Cb750 dohc valve adjustment BTW, there are DOHC sites that specialize in them. They are considered more difficult to maintain because of the vacuum carbs and use of shims for adjusting valve clearance instead of the screw and lock nut type on the SOHC. After that it ran, sort of. Adjustment, testing and troubleshooting Basic Carb Terms The carbs are numbered the same way as the cylinders on the bike – 1 through 4 left to right as you sit Sep 6, 2023 · Cb750 valve guide1 Cb750 k2 ep. Mar 9, 2018 · When the valve seats get cut the valves sink deeper into the head, that being in an up direction, then the stems become too long. My 97 TL1000 has an inspection interval of 15k miles, but so far (currently have 35k on it) it hasn't needed adjustment since new. The valves tend to close up to no compression. You may start seeing oil seeping around this gasket and if it's not taken care of Dec 16, 2012 · Found these a while back and the Admin over on CB750C. Did you ever adjust the chains? Not doing that and they then buzz from being Jun 11, 2006 · Yep. I don't mean thickness, I know those are supposed to change, but what is the diameter of the shims. It doesn't cover the cam positions that well, but it shows you how to measure the clearances and remove the shims. Valve adjustment for sure. Odmckee CB750 New member. 1979 to 1983 DOHC CB750/900/1000/1100 Honda Custom: Forums I now can do valve clearance adjustments on the DOHC 750! Took 7-10 hours in three shifts and the bike Aug 20, 2020 · Hey forum, Background: Currently doing a lot of basic maintenance on my 1982 CB750f, my first post here was a few weeks ago and you guys were great help so here is another question for my current problem. inspect and clean. I am impressed at the way they capture the little plugs on the end of the valve cover in the gasket. The engine can be run until compression drops to 120 ish and then they will be getting weak. 005"-. Basically you need to check the gaps between the valve shims and camshafts. Swapping the shims to the correct sizes to achieve 5 thou of clearance is "adjusting valve lash" or "performing a valve adjustment" on this bike. Now, I have had a specialist Honda Technician pull my carbs apart, replace Idle air control valves, check plates, jets, alignment, clean the carbs, lubricate lifters etc etc. K exhaust: 41 grams. It's relevant for the Honda CB750, CB900, and CB1000. Jun 7, 2013 · This seems to be important. Cam Chain Adjustment. Jun 25, 2021 · The only reasons as to this issue is either throttle valves sticking, or vacuum leaks. So the good news is I got the 1980 CB750F (speedometer indicates 31,000 miles +/-) back on the road after rebuilding the carbs and brakes and absolutely love it. Apr 4, 2020 · No, but valve adjustment is called for as nobody ever did them. Register for free to get updates on all our auctions and to bid or sell. According to the shop manual, you adjust the exhaust valve on #2 and the intake on #3 at the same time. Below 4500 RPM it coughs, misfires and splutters and has poor acceleration Jun 27, 2019 · Valve adjustment/check dohc Q: "Does anyone have step by step instructions for checking the valve clearance on a dohc cb750?" A: "Download the FSM from the front page of the site. 005" instead of the service manual spec of . the crank is moving, can here compression, but the cams aren't Sep 21, 2020 · The DOHC Garage (1979-1983) . Disengage the choke and the bike just cuts out. I got this bike from a guy The manual describes how to turn the cams 90 degrees each time to check certain valves each time (not the engine 90*) . com Apr 10, 2021 · The Honda CB750 K2 project is gaining a little more momentum now the remaining parts have finally turned up! In this video we set the valve clearances on thi Mar 21, 2023 · Yes, changing valve shims can change your carburetor synchronization if the carbs were previously synchronized with the valves not in perfect adjustment. Dec 31, 2016 · Put engine on TDC #1. It also has an oil seal inside of the May 5, 2014 · How to Help the Channel:1. But back to the wider shim sizes, is it possible that i measured wrong? Nov 5, 2012 · Most machine shops I know of dont even lap valves after a valve job is done. 012" IN/Ex. Apr 17, 2006 · No valves to adjust But seriously, valve adjustments are not a big deal and most (jap) bikes hardly ever actually need it. TDC for Valve Clearance Adjustment. Jun 27, 2019 · Valve adjustment/check dohc Q: "Does anyone have step by step instructions for checking the valve clearance on a dohc cb750?" A: "Download the FSM from the front page of the site. Aug 28, 2019 · Here's a good video for checking valve clearances on the DOHC CB750s. On both cylinders, even with the adjustment screw backed all the way in, the rocker is sitting tight against the top of the valve stem. cb750kz CB750 Big Bore Engine by RPE – rpengines. I thought the carbs were buggered but nevertheless the valves needed adjustment. 12mm or . Question: Hey all My buddy and I just finished adjusting the valve clearances on his 83 CB750 SC. Should be pretty close to base idle. Compression I pulled the valve covers and adjusted the cam chain tensioners to take out the slop in the chains. Feb May 29, 2017 · Bike does not rev high and dies immediately if put in first. it appears someone was in here before me and all the valves need adjustmentIn inches they are 4-6 thousands. Carbs needed cleaning, to get rid of the old dried up fuel. I'm not a pro mechanic if you know what I mean, I'm just getting started (its my first bike actually). If the slides are held open too far from binding no amount of idle screw adjusting will get the mixture right. If that's the case here, there is no solution besides splitting the crankcase and replacing the chain (basically total engine overhaul). 750_cafe; Apr 15, 2024 Jun 14, 2016 · The 79-82 DOHC offer a little more power and better brakes. Cyl. Apr 9, 2017 · Hello all, I am new here - I have come across a problem in the rebuilding process of a DOHC CB750 and I don't know where else to go! A little background about the bike: 1979 CB750K DOHC engine fit into a SOHC frame, mileage is unknown, started to make cam noises (spinning noises) so removed Oct 5, 2021 · Rather than run with complicated DOHC designs (like the CB450), the CB750 would roll with a slightly more dated SOHC setup (up until 1978). any kind of step by step for a valve job? a link would be appreciated or any leads thanks in advance. Nov 2, 2023 · SOHC and DOHC engines are the same kinda with differences and upgrades / changes from year to year. Highest risk is on exhausts. Much to my dismay, she made the same noise she made when I first bought here. supamandasun; Feb 20, 2024; Replies 5 Views 530. … Honda CBX1000 | CB750 and CB900 DOHC. May 17, 2014 · so i just finished putting together my 79 750f brat trying to get my carbs tuned right this is what ive got. Messages 1980 cb 750 tuning. Ron Burgundy my 1975 CB750K! Parts used are I found the first couple of adjustments on both my K5 and K1 to be slightly difficult in the fact that you have to learn the best angle and position for the feeler gauge based on which valve you are adjusting. My valve shim inspection was unsurprising, they all had absolutely no clearance. I recently did a 2 hour trip with her back and forth and she was awesome. 100 psi is a dead cylinder. Camshaft chain Valve weight will also be a factor in making spring pressure decisions. Drive pinion oil leak. It has some issues but I have been working on them rapidly and making her run as smooth as she deserves. 1980 CB750 Custom Just did compression test and was surprised by the numbers. The plunger bar is a machined fit in the hole of the housing. Is the OEM Honda two piece tool (07964-422000A) better to buy or the MotionPro Jan 17, 2024 · Listed below are manuals that have been sent in to share with the CB750 community. But, luckily Mitch knew what we were doing and got me up to speed. My accelerator pump was working great 2 weeks ago. 5 intake: 49 grams. 8. Bike status: Carb clean twice and float re-adjustment. I haven't run the motor yet but i did check cold compression (carbs off so no throttle) as part of my winter work and im getting pretty low compression on the cylinders. noob move. But after the knob is maxed out CW bike still dies eventually. . There is lots of info online too. The DR-Z/TLR/TLS motors usually have to put a little RTV in the bottom Honda DOHC Customs - 1979 to 1983 DOHC CB750/900/1000/1100 May 29, 2017 · Bike does not rev high and dies immediately if put in first. Submit Oct 15, 2024 · In this video we will see how to adjust the intake and exhaust valves with the head on the bench. 15 valve clearance adjustment #1180Cling on for dear life !!!: honda cb750 Cb750 chain. I added a small washer to shim the needles of the Keihin Carb pack. 001 which coincided with the lowest compression reading at 90psi. I've just measured my clearances, with the results shown below. Then get bike running and drive the crap out of it. Jan 13, 2017 · The DOHC Garage (1979-1983) Adjust the valves to . I have scare’s from Jan 19, 2017 · These DOHC commonly had valve sealing issues even brand new when people refuse to check the valve clearances because they had to buy shims and then the slides again begin to drop in response to that. As i am currently assembling mine for my project, I am intimately aware of their construction at least for the K2 and the parts microfish indicates it's the same for the K8. Fits CB750 (ALL) 79-82, CB750SC 83, CB900C/F 80-82, CB1000C 83, CB1100F 83, CBX 79-82. 1 valves are loose and can be moved slightly with your fingers then that is the cyl. No need to find TDC, the cam positions are easy to find by reading the manual. 005", the bike runs longer and better. Jul 11, 2023 · Valve seats rather than valves. C should be same as K and F on the DOHCs. That is your front cam Chaim tensioner adjustment. CB750 DOHC HONDA VALVE CLEARANCE - YouTube Oct 1, 2024 · On my 1979 DOHC CB750 also had the same issue that persisted and demonstrated the same behavior. I pulled the valve covers and adjusted the cam chain tensioners to take out the slop in the chains. The tighter valve clearance specification listed in the manual, which has a minimum of . Will definitely purchase more from this supplier if needed. 002 inch feeler gouge, very tight, almost no clearness at all. Now Idle remains where set at about 1200 rpm - in my case, I had to replace the original pipes which I loved. 003 and a . This Honda DOHC CB750 / Clutch adjustment / Throttle adjustment / Air filter change / Tune-up / Cylinder head nuts / Camshaft chain adjustment / Valve clearance Jul 27, 2012 · The factory Honda manual for the cb750 says adjust valves every 3,000 miles, I have a bigger cam so I check every 1000 but rarely need to change the clearance. The DR-Z/TLR/TLS motors usually have to put a little RTV in the bottom Sep 21, 2020 · The DOHC Garage (1979-1983) . This is safe for the valves, but surely would decrease performance, right? I may not be checking the clearance at the right cam positions Jul 4, 2014 · I'm slowly going through all the maintenance items the previous owner neglected on the car (mismatched spark plugs, maladjusted clutch, burned out bulbs all over, chain not tensioned, cam chain never adjusted, etc) and one of the most major items from my perspective would be a valve adjustment Mar 25, 2020 · In this video I do the routine scheduled maintenance as recommended by the Honda factory service manual. Apr 9, 2017 · Hello all, I am new here - I have come across a problem in the rebuilding process of a DOHC CB750 and I don't know where else to go! A little background about the bike: 1979 CB750K DOHC engine fit into a SOHC frame, mileage is unknown, started to make cam noises (spinning noises) so removed Jul 27, 2012 · The factory Honda manual for the cb750 says adjust valves every 3,000 miles, I have a bigger cam so I check every 1000 but rarely need to change the clearance. I have 4into1 delkevic exhaust and individual K&N pod filters. Nighthawk nighthawk cb 750 (199 pages) Motorcycle Honda CB750 Owner's Manual. Having a 1992 CB750 DOHC (Nighthawk) I am required to do valve adjustment NEVER!!! WOW!! But it is important to have clean engine oil to keep the hydraulic lifers clean. Before I tore into it to check valve adjustments I wanted to verify pilot settings. The bike is able to stop and start easily while the bike is warm. Chapter 1 Nov 27, 2007 · After adjusting, check them again within 500 miles. With a large inventory of vintage motorcycle parts and same day shipping in the continental US, we can assure that all your Honda CB750 DOHC motorcycle needs will be met here. Setting float height on 1979 cb750K Fairly new to working on CB 750's and just looking for confirmation of process. 1982 CB750 DOHC The head is removed, awaiting new head gasket. 9) Turn the crank over 360 degrees clockwise (always clockwise) until the T lines up again on the T-F 2-3 mark. The camchain should be set when cylinder #1 is 15 degrees past TDCC or #4 is passing TDC WHILE THE INTAKE VALVE IS STARTING TO OPEN, stopping in that forward direction at the "corner" of the spark advancer: that's the 15 degrees point. 150mm. pod filters kerker 4 into 1 110 main jet 75 pilot jets 2. It's my belief that it is these reasons that a SOHC in good condition is harder to find then a comparable DOHC. So ive done my Dec 26, 2006 · I have an 82 DOHC and have developed an oil leak from the intake cam chain tensioner adjustment. Are you sure it's the cam chain? DOHC Honda engines have a chain primary drive, and they are well known to get really rattly as the chain stretches. 002" from them held open while running. Once the engine cools I have trouble starting the bike without increasing the turns in the idle adjustment Valve Tappet Clearance Adjustment. If you adjusted cylinder 2 in the previous step then you can now adjust cylinder 3 or vice Jul 28, 2023 · Valve lash is the distance between the camshaft lobes at 0 lift and the surface they push on -- in this case the shim itself. 5mm from the arm. to adjust. I am fully sure this is not a fuel/air or throttle valve issue. raene; Jul 4, 2014; Replies 1 Views 7K. May 19, 2014 · '81 DOHC cam chain adjustment proceedure. Low compression on 3 of 4 and what got me to this point is that cyl. A quicky valve adjustment and the thing ran perfect again. Nov 25, 2017 · I'm doing the valve adjustment on my 81 750 while the engine is out of the frame. I think the best way is on a milling machine which is expensive. As far as the intakes go, the ones that are reading . Feb 8, 2017 · Here I demonstrate how to replace the pesky 90's CB750 valve cover gasket. If I replaced the valve guides and valves, does a new seat need cut in the head or can I grind it (using stones from Goodson as described in hondaman's book?) The current seat is in decent shape but I wasn't sure if it would be possible to have the new guide in straight enough to get away with just a light grind. I don't want to be too rough as I know these parts are delicate for clearances, especially around the Feb 1, 2020 · I guess my question is which jet controls WOT? I have totally rebuilt my 1981 CB750C. Honda DOHC Customs - 1979 to 1983 DOHC CB750/900/1000/1100 Jan 18, 2020 · Hi guys - hope everyone had a good week. I mean it is very tight, less clearance than a valve in a valve guide. Sep 4, 2023 · Chasing some advice on tuning the 4 KEIHIN Carbs on my CB900. You should really get familiar with it. Would a small easy out be my best bet? Open to suggestions Dec 26, 2022 · In practice it is ok to have the lobe apex 180 degrees from the shim (pointing directly away). Can it be related to loose Aug 25, 2020 · This video shows how to properly adjust the cam chain tension and valve clearances on the Honda CB350F, CB400F, CB500K, CB550, CB750 family of motorcycle eng May 11, 2014 · Hi there, I checked today the valve clearness on my CB750F 1980, all 15 valves where in the correct tolerance except the the 2 exhaust valves on cylinder 4 that are well to close, I couldn't even insert 0. 007", carbs cleaned, pilots adjusted out 2 turns (new washer and o ring), new air cut offs, carbs were bench synced and vaccuum synced. Oct 28, 2015 · So I'm measuring my valve clearance and I'm getting some wayyyyy wide readings. The inside of the CB750 is truly magical. Has to be the O-ring (number 20 in the parts diagram above) and have sourced said O-ring. Durable rotating components like a single-piece crankshaft, durable, easy-to-adjust valves, and an easy to repair chain drive would make long-term running and maintenance on the 750 a snap. Dec 18, 2014 · Turn the screw in until the slides just start to move then give it another turn. The Feb 15, 2022 · Hey guys! I just bought a 1981 CB 750 Four. If no. Jul 28, 2023 · Good evening, everybody. Messages 6 Reaction score 0 Points 1 Location Virginia. Like 120,60,30,40. the crank is moving, can here compression, but the cams aren't Jun 25, 2021 · The only reasons as to this issue is either throttle valves sticking, or vacuum leaks. Use promo code "GJD10" for a 10% discount on a quality knife from Odenwolf at https Jul 8, 2024 · Hello, I recently purchased a 1981 Cb750 custom and it has the issue with the idle hanging when coming to a stop. Nov 19, 2024 · Mostly that loose after adjustment using the combo of shims i had to bump the clearances up a bit, that's what i ended up with. I am working on a motor that has just been broken in Jul 31, 2021 · However, my question is on valve clearances. Standard procedure is to set the valves again after any valvework. 4mm clearance between the rod and the arm. All comes down to what you like. version. It is not a vacuum leak. 1 = 95 psi Cyl. Coils, wires and plugs have all been replaced, valves set to 0. Forums. Apr 25, 2020 · The rod rests on the control arm when the spring is out. 5 grams. 2. Is this a teardown or can I replace that cover, smooth the cam, adjust clearances and run it? I'm assuming it would have made horrendous noise if that valve were bent or broken. 4. It's not hard to do but very fiddly, best bet is to get yourself a manual. Carb rebuild 5. Mar 21, 2016 · Also, the bike didn't want to idle last week and I got to messing with the adjustment where the throttle cable goes into the carb bank and the idle air mixture knob (the only adjustment knob/screw I have located on the carb bank[Black plastic knob underneath the carbs in the middle]). I took off my bowls to put in new needles (I was having leaks) and noticed a couple of tiny bits of crap in the bottom of the bowl. cb750, cb750c, cb750f, cb750k, cb750sc dohc 4-valve cb900, cb900c, cb900f This is a how to video to show you how to measure and adjust your valve shims on a Honda CB900. i know theres a quality carb guide. One of the intake valves on cylinder 4 seems like its getting stuck open, or halfway open atleast. I’m just hoping to get the seats a little less pitted and then lap the valves themselves. au CB750 Big Bore Engine. What I don't know and haven't come across any information about is how quickly valves clearances on this bike change. Mar 18, 2017 · Anyway, I've been reading through the Clymer manual regarding where to start the adjustment for the pilot screws on the carbs (I think they specify 1 1/2 to 1 3/4). Mine currently sit at approximately 3 1/2 (for all 4 of them), but I really have no idea if this is remotely correct or the PO was just fiddling around. I'm getting readings ranging from . Recheck and adjust carb balance750's very picky about carb balance and unsettled idle. Posted by Peter on 30th Oct 2020 Nov 29, 2015 · My opinion on the valve clearance is that all of the exhausts are on the tight side and should be adjusted. Lapping is not a cure for leaking or worn valves or seats. F2 exhaust: 47 grams. Ever since I got this bike the idle has been 'hanging' high only when the engine is Hello everyone, I'm in the process of rebuilding my first engine and was wondering how you guys remove the carbon build up on/around the valves ( if its even necessary to remove all of it ). Mar 29, 2022 · 5. The final stwp before we can balance the carbs - cam chain adjustment. 004"-. Apr 12, 2023 · Some are setting top dead center for cyl 1 and adjust exhaust and intake for cyl 1, exhaust for cyl 2, and intake for cyl 3. Loosen the lock nut and then loosen the bolt on the underside of the tensioner a couple of turns. Sometimes if the exhaust valves have a bit of carbon buildup on them to leak a bit the hard dogging of engine then lets it get beat off if the valve is a bit loose to allow it. for stock camshafts. CB750 Member. Aug 28, 2019 · 1980 Cb750c So Im stil new to doing my own wrenching and have just learned about doing valve clearence checks of course after i replaced my cylinders, jugs, rings etc. 10mm - Pkg 20 from Randakk's Cycle Shakk. im looking for a comprehensive valve adjustment guide here for my cb900c. S. The most common thing that gets done then is that the carbs then get blamed (it's a male testosterone thing) as the problem and then how you find May 17, 2013 · from what the OP said, he had a valve adjustment done (which will not correct any of the issues causing oil to be burned in the cylinder). com. Mar 16, 2015 · hi everybody, this is my first post just picked up a sweet barn find for $200, 1980 cb750k was told the timing chain was broken, got it home, pulled the valve cover and the right side engine cover and turned the engine over. Feb 17, 2023 · I want to buy a good tool for adjusting the valves on my DOHC CB750k. The noise sounds like the starter motor turning over, but nothing else. It looks like whoever did it last confused the . 0015" and I couldn't get it between the shim and cam lobe on any of the valves. If there is a problem with the seat or the valve lapping may make it seal for a while but if the seat and/or valves are worn it needs to be fixed correctly. The recommendation is that it should be closer to . 003", the engines commonly burn valves at . Can I simply install each camshaft in the correct position (using the small mark on the right Z1 Enterprises is the leading destination for Honda CB750 DOHC Engine Gaskets and Seals. I've triple checked everything and I'm stumped. choose your desired size and quantity from 200-315 shim size. ) As per step 5, check which cylinder is on the compression stroke. Looking for advice and or someone in the cedar rapids IA area with Buy your Valve Shim Kit - 25mm Diameter - 2. 006" is now the preferred clearance in order to prolong valve life. Bank breakdown 2. These valve weights are for Cycle X valves: F2 intake: 47. Stop trying to go against Honda engineers and go with the stock spec. 4 are loose, then obviously adjust no. Honda must think that 90* cam movement is simple and accurate enough to do the job. With the spring in it is 0. 005-0. it ran ok and wasn't noisyI don't know how much you can cheat on this but even shuffling the shims around I'll need about 8 of them. Carbs cause many issues for many people on the dohc. Jan 30, 2012 · 1. 25mm valve adjusting shim. pdf") -- I finished my valve tappet clearance check/adustment today after some distractions the past 2 days. It is the same for most duel overhead cam motorcycles includ Aug 20, 2017 · Clearance specs for 79-83 cb750 valve clearance Aug 13, 2017 · Cb750 carb adjustment help. 0015 didn't fit. Bronze Valve Guides must be hones or reamed to size AFTER they are installed in the head. Aug 6, 2016 · Even as simple a thing as valve adjustment can make the pods more problematic, these engines are known for being freaky to set valves on, you set looking for . Is there anything in the hole? Aug 27, 2015 · Valve Cover Gasket Question. I'm getting ready to do a valve job on my DOHC 750 and cannot find the correct size shims. After the cam shaft depresses it open, it doesn't retract all the way. Electrical system came up and it rides surprisingly well despite still needing everything Apr 27, 2016 · That "valve" you speak of should have a bolt and nut in it. Reply. 005 inches. Valve Adjustment using Sean G's Excel Spreadsheet (screen grap of final measurements attached) 6. Apr 20, 2020 · The valves CANNOT be ground, seats can, replace valve only at like $25 each, you will discover this engine to be very expensive to rebuild. There's also damage to one edge of the cam lobe, it's sharp. _____ Valve Guides Standard (fits both intake and exhaust) Fits Honda DOHC CB750C/F/K/L CB900C/F CB1000C CBX CB1100F. Cheap to do now instead of later. 05mm spec with . Jan 30, 2007 · Holds valve spring bucket down so adjusting shims can be removed. Valve cover is off at this point and about to check clearance. Mar 26, 2023 · Hi. Then rotating 360 degrees for cyl 4 to be at top dead center again and doing the rest of the valve adjustments left. The rework is to use thinner shims to make up for valves too long now. Non stock camshaft valve lash can vary. Most valve seats (to my knowledge) can be cut. Earlier attempts did not feel correct and rather then continue with the engine installation, How to adjust Cb750 valves and cam chain tensioner!In today's episode we are starting the basic tune up of Mr. 075mm, can lead to burnt exhaust valves over time. If you happen to have aftermarket, high performance parts installed or you regularly run the motor hard @ high rpm then adjust all to . 007 or greater should also be adjusted at a minimum. Simply put I have to hold the throttle to keep bike at 1000-3000 rpms. New posts Search forums. 006" for CB750, CB1000 and CB1100 with slight differences, which will be noted. Besides, needle is mostly 1/4 to 3/4 and you've already said your problem is 1/4 to 1/3. We are your #1 source for Honda Vintage Motorcycle Parts. Personally, were it mine, I'd adjust the intakes that are currently . 006 with one . Been so long since I used the OEM valve setting marks I can't say, I didn't like setting like that, probably OK what you are doing though. 81 Honda CB 750 Custom Persistent Charging Issues- HELP!! Klackey; As measured with my caliper, the valve shim was perfect. 2 was cold at first. 006, and one . adjust, or replace if necessary. 005" on the valves. Mar 16, 2021 · I wanna hit the clearance of 0,12-0,17 on every valve. 5 turns on the a/f screw 4 washers on the needle the bike has good throttle response now when its warmed up but the idle is very Sep 14, 2021 · You can not sumpley put the air mixture screws at 1. Later model addendums and specific wiring diagrams are at the bottom. My bike runned like crap in the high rpm range, these clearances can verify these issues. May 12, 2022 · Anything you want to do with the sohc, parts are available for the most part. Unless specs have changed for later models and I missed it,correct valve lash for 69-78 CB750 K and F is . more. Bank rebuild 6. Please comment, like, subscribe and share!2. The needle clip is 4th from the top. Aug 23, 2013 · Hey folks, I got this little problem here : I want to adjust the clutch pack on my 1980 cb750 (there's too much freeplay on the gearshift selector) but I have to get pass this damn bolt here. This Honda DOHC CB750 / Clutch adjustment / Throttle adjustment / Air filter change / Tune-up / Cylinder head nuts / Camshaft chain adjustment / Valve clearance Mar 16, 2015 · hi everybody, this is my first post just picked up a sweet barn find for $200, 1980 cb750k was told the timing chain was broken, got it home, pulled the valve cover and the right side engine cover and turned the engine over. 5 K&L valve adjustment shims. If the no. Aug 19, 2023 · Everything on the exhaust side is . Mar 4, 2024 · So 1980 CB750F Idle with choke engaged sits kinda high at around 3000rpm. Replaced the cracked cam cap "D", new valve cover gasket, new valve cover bolt rubber. The current jetting I have is a 135 secondary main and a 80 primary main. First question above: "What is TDCC?" That's "Top Dead Center, Compression" stroke. 005 or . Any types of sealers won't last so I would recommend not trying any sealers to fill the hole. I noticed 3 screws were accounted for and the 4th appears to have been snapped off. K intake: 45. In this video I adjust the valves on a Honda CB750 Four (K2) in preparation to synchronize the carbs. 5 turns out you have to adjust each one to get the highest idle on each cylinderbwhen you adjust the airscrew you should have your bike idleing low so you can tell when your adjusting the airscrew by how fast or slow it's idleing when adj turn the air screwvon eachvcylinder to get the highest Jul 16, 2024 · Depending where the hole is it can be welded up. Adjust valve clearance of the cylinder that is on the compression stroke. 1979 through 1982 Honda CB750K/C/F/SC Service Manual U. With 3 turns out on Clymer manual for the Honda CB750 DOHC fours from 1979-1982 Clymer motorcycle repair manuals are written specifically for the do-it-yourselfer. 004 and leave the rest as-is. Carb breakdown 3. 007, and on the intake same . Valve clearances are never checked on dohc and have caused the death of many of the dohc engines. Nov 6, 2019 · If too small, the risk is burning a valve. I followed the manual (specifically, pages 42 and 43 of the fsm I downloaded from the 'Manuals' section of the SOHC site, filename "Honda CB750 SOHC K0-K8 F1-F3 Shop Manual. No dice. If you have additional manuals you'd like to share with the members, or have concerns about any of the manuals below being shared, please email admin@cb750. So I am preparing the valve clearances and want to know how to mock these parts up. 3 = 50 psi Cyl. Valve adjustment. Then other people are setting top dead center for each cylinder they are about to adjust. I'm worried about that one with 0015, hope it's not an exhaust valve (but I bet it is). It then lowers the compression. Forum: The DOHC Garage (1979-1983) K. I've seen 29mm -- is that right? Can't find the info in the service manual Jul 12, 2018 · I adjusted the valves on cylinder #1 no problem. 100mm to . 13mm. May 19, 2014 #1 I just bought an '81 CB 750K. 003" Ex. K oversize 33. I have done the timing and the valve clearances. Just got the carbs to sort now. Tried to adjust idle knob with a small increase in idle after turning clockwise. If you are going with a complete engine it would be wise to check the chain guide and replace if needed. 4 = 70 psi How can these be this low and bike starts and drives? Valve clearance must not have been done by previous owner and if I understand right, the Oct 10, 2021 · Good day New here and working on getting a 80 750k running properly. Just to let you know I’ve sorted the valve timing out & have 4thou on all 16 valves now!! I did a compression test yesterday & got 135 on all 4 cylinders, before I did the valves #3 was 105 (obviously valves being held open) . 750SSCafe; Honda CB750 DOHC (1979-1983) Discussion. Its running, and i have to say it runs pretty well tbh. Something that is often overlooked & if left poorly adjusted can cause internal engine Sep 27, 2023 · What’s up with the idle adjustment on the 750’s ? I know the book says adjust at operating temperature but Man oh Man is it hard to keep from burning the snot out yourself!! I have large hands and they hardly fit in the hole you need to reach into and turn the knob. Jul 22, 2010 · I had a 1973 cb750 I overreved one time and backed the valve adjustment nut all the way out, a common problem. amc49 Aug 23, 2023 · Honda CB750 DOHC (1979-1983) Discussion. It was in storage for 5 years, and not running when I bought it. Aug 19, 2023 · The #4 exhaust valve next to that cam was super tight, the . anyone with experience please chime in and any previous mistakes i will be sure to read carefully. Don't be surprised that on a poorly-maintained engine, there are several with zero clearance. Clean 4. I prefer the looks of the sohc over the dohc. The bike ran fine but sounded like someone was hammering the engine from the inside out. Then rotate 360 deg to T mark 1-4 again and do the other cyl. When opening full throttle the arm stops just short of contacting the pump rod bottoming out on the idle adjustment housing notch. My concern is removal of tensioner adjustment bolt without removing the valve cover. com gave me permision to share. 1 valves are tight and no. 5mm Kibblewhite 34mm intake: 38 grams 5mm Kibblewhite std exhaust: 29 grams Note: Mar 13, 2016 · Double check valve clearance and make sure the low cylinder has at least . 004. The #4 exhaust previously had several . When a valve gets adjusted to the correct clearance from an incorrect one, the amount of air it allows through at maximum valve lift also changes. Same goes for 16 valve kawasakis Hi. I had a little trouble wrapping my brain around the design. I did notice that Aug 18, 2024 · Now, if it were my engine, I'd be checking the valve clearances carefully before removing the cams, then if any need adjusting (swapping shims) it's easy while you have the cams out. There could be carbon on the seat which will get "beat" off once you adjust the valves, which would be good. Replace Fuel Hose & Carb to Engine Boots Last weekend, I attempted to start the bike. I know all about the factory specs, and how the general opinion is that . Posted by dammitdave on 8th Apr 2022 Worked just fine, Quick shipment and had them in stock 5 Valve shims. Head has valves, springs, shim bucket installed. 2 = 100 psi Cyl. so do I lower the fast idle speed or do I simply increase the idle? And in increasing the idle, do I adjust the pilot screws or just the black knob beneath the carbs? Thanks First question above: "What is TDCC?" That's "Top Dead Center, Compression" stroke. honda cb750 | Motorcycles | Gumtree Australia Free Local … Find honda cb750 ads in our Motorcycles category. Jun 11, 2006 · Yep. The book says to “bend the adjustment arm” to get between 0 and 0. e. honda 50k cb750f clean replace adjust luamcate frequency item fuel lines throttle operation carburetorchoke air cleaner crankcase breather spark plugs valve clearance engine oil engine filter cam chain tension carburetor-synchronize carburetor-idle speed drive chain battery brake fluid 'front) Apr 7, 2023 · So firstly, the valve clearance in the factory service manual is too tight for long-term use. a proper valve job (i. Many can be replaced entirely if you are doing a full valve job. The process is in 6 steps: 1. Dec 29, 2023 · I am having problems with my cylinder 4 spark carbon fouling on my 79 750k. Do a search for "adjust can chain dohc" for a video description. The "nay-sayers" will tell you you shouldn't trust a riveted chain, but every single link of a chain is a rivetted assembly anyway, so as long as you form the end May 4, 2017 · I get my carbs within 2 cmhg of each other which I believe is close enough. Tags carburetors cb750 dohc carbs tuning dohc O. 30mm-3. The RC 315 cam in my unit is set at . The internal plunger is spring loaded and will apply the correct tension to the chain. Most ports are all pretty out of whack mostly tight so my crank shaft is pretty hard to rotate. The bike idles between 1000 and 1200 rpm. Many consider it to be the first superbike and we still think it’s worthy of that title. Sep 14, 2021 · Hi there, adjusting the valves is important and can be done yourself with basic tools. Honda also recommends adjusting the timing chain at the same interval. Air Cleaner. They are broke down in chapters for easier downloading. If the valve is burned, the clearance will keep closing up and you'll eventually lose compression. Mar 15, 2018 · Hi all, thanks for all the replies. 1. After getting all the shims put back in their buckets, we are running in a weird issue. 002" to . 002" In and . amc49 Jul 22, 2010 · I had a 1973 cb750 I overreved one time and backed the valve adjustment nut all the way out, a common problem. My thinnest gauge is . removing the head, getting the valves and seats recut and ground, replacing any gaskets that are removed or exposed as a result of removing the head, and replacing the valve seals hey guys. Thank you to everyone who contributed. For adjusting valve clearance on twin cam models. xzda aibxyc xusipv hlehaiv jnjn trtt hfjlmlw zjotii gxtu thysi