Restoring a vintage motorcycle - 1980 Honda CB900C - Part 2 - Cam Chain Tensioner Adjustment

In this video, I am adjusting the cam chain tensioners on my 1980 Honda CB900 Custom. The procedure is the same for all early 1980's Honda CB900 and 1979-1982 Honda CB750 models. As far as motorcycle service jobs go, this job is pretty straight forward. I go through step by step. If you have any questions or comments, please feel free to leave them below.

[@giribardi_yt841]

grazie per il tutorial, l'ho seguito passo per passo con la traduzione automatica in italiano di youtube e ho risolto il problema. Grazie sei un campione #1 🇮🇹

[@jonsmotorcyclerescueandrev3538]

Grazie! Sono felice che il video sia stato utile. Saluti!

[@paulplantinga2865]

Thanks Jon. I followed your advice. Engine is now much quieter. I bought my '81 CB900C 4-years ago with just under 12,000-miles. I've only added about 500-miles. Now retired and planning to use it much more.

[@jonsmotorcyclerescueandrev3538]

Awesome Paul! I'm glad the video was helpful. Enjoy the ride!

[@sgranty02]

just done this wow what a difference! my engine now doesn't sound like something is trying escape! great video

[@jonsmotorcyclerescueandrev3538]

Thanks Stuart! Glad the video was helpful.

[@richardknott2021]

Love your channel..very informative..

[@jonsmotorcyclerescueandrev3538]

Thanks Richard!

[@TheMarcball]

Interesting. I just grabbed a kz440 Ltd 1982... for my wife while I'm still on full strip down of the 1981 Kz1000Ltd... I guess I'll get to the cam tensioners soon enough... Thanks for the inspiration and keep on trucking!

[@jonsmotorcyclerescueandrev3538]

You probably already know this but just a heads up: the tensioner on the KZ is completely different than the Honda. There is a single unit behind the motor (external to the motor). Your shop manual should have the correct adjustment procedure if it's adjustable.

[@jaymesims3070]

excellent Jon. I have the very same bike in the garage. Will be doing the procedure this weekend.

[@jonsmotorcyclerescueandrev3538]

Nice! Doing this procedure eliminated the slight cam chain noise on mine during startup.

[@GCharlton56]

To all: I've got a clean 1982 CB900C Custom for sale. Looks identical to what is pictured in the video except my cylinders are black. I am in the Columbus Ohio area. Message back here if interested.

[@davidroberts8854]

John, I just aquired a cb 900 custom from my father in laws estate. Looking at replacing all fluids, hosed etc. Thanks for videos.

[@jonsmotorcyclerescueandrev3538]

Hi David, you're welcome.

[@BricksAxeMan]

I have a CB900C and I love the forward controls you have on the featured bike. Who makes them? I need this in my life!

[@jonsmotorcyclerescueandrev3538]

Hi Chris, the controls were custom fabricated by the previous owner.

[@ThrillaPark]

Just found your channel. Subbed. Some time ago I saw a version of this job where the engine is running while doing the adjustment with the acorn nuts. Is that a valid method?

[@jonsmotorcyclerescueandrev3538]

Hi Alex, I saw a similar video where the bike was running during the job but that isn't the procedure in my shop manual. When in doubt on any important project, go to the true info source - check with the manufacturer. You will save yourself lots of money and frustration in the end.

[@mschott2297]

First, great Video thanks. Then, I have a both a Clymer and a factory Honda manual. Clymer says to do it the way you show. The factory manual says it can be done with the motor running and warmed up or your way on a cold engine. Just sharing info.

[@HotRodMediaByDrew]

Hi, I’ve got a 1981 750C and I’m did the adjustment or at least I think I did I pretty much ended up backing them like all the way out it feels like and it helped a little I also did this while running so that might play a part? I would like to do it again ur way should I tighten them all the way back down?

[@jonsmotorcyclerescueandrev3538]

I would suggest following the steps in the video. I'm not exactly sure what you're asking and I don't want to advise you incorrectly. 🙂

[@HotRodMediaByDrew]

@@jonsmotorcyclerescueandrev3538 so I’ve already done it once while running cause another video did that. I want to do it again ur way with it not running. Should I turn them back down or keep them where there at now ?

[@jonsmotorcyclerescueandrev3538]

@@HotRodMediaByDrew The adjuster locking bolts should only be loosened briefly to let the internal springs take up the chain slack and then tightened back down to lock the adjusters in place. Then the locking nuts get tightened to hold the adjuster locking bolts in place.

[@rodofsteel6662]

Hello, i have an 81 cb900c and it seems to have no vacuum leaks or any carb issues. After I ride about ten miles and it gets warm I pull the clutch in to stop and it revs bad around 3,500rpm. I have read it could be a clutch adjustment issue or timing advance, my cables are all fine also. Would you have any idea what this might be? Thank you.

[@jonsmotorcyclerescueandrev3538]

I had the same problem recently on a similar Honda. It turned out to be a blocked port for the idle circuit in one carb. Before getting into that however, turn your idle adjustment screw to adjust the idle to around 1200 rpm after it is warmed up. If that fixes it your problem is solved.

[@rodofsteel6662]

@@jonsmotorcyclerescueandrev3538 thanks I’ll try that.

[@mexiflush8077]

Hello, Jon I recently got my 1980 cb750 running again and noticed that the cam chain tensioner bolt is leaking. After some research I found out there is a O-ring on the bolt for the exhaust side of the engine. But I cannot find an exact answer on how to replace the O-ring. Would I be able to just loosen up the locking nut and completely remove the bolt replace the O-ring and put back together?

[@jonsmotorcyclerescueandrev3538]

Great question. I would check with the service manual and maybe talk to Honda to be sure. I don't know the answer off the top of my head. Cheers!

[@mexiflush8077]

@@jonsmotorcyclerescueandrev3538 thanks

[@jonsmotorcyclerescueandrev3538]

@@mexiflush8077 You're welcome.

[@brendonsummerton3509]

So maybe I missed it in the video, but how do you know when it’s at the correct tightness? Typically you measure the slack but since this is an internal chain I don’t think you can do that lol

[@jonsmotorcyclerescueandrev3538]

You don't. This is an adjustment that you do blind and hope everything went well. If your chain was making noise before, hopefully it is quieter now.

[@brendonsummerton3509]

@@jonsmotorcyclerescueandrev3538 is there a good way to determine for sure if it’s the chain or not? I have a little bit of what I would call valve chatter but I’m not certain that it’s the valves. I reckon it could be the chain or any number of other things from what my research has told me

[@jonsmotorcyclerescueandrev3538]

@@brendonsummerton3509 The easiest procedure to do is setting the chain tension as outlined in this video. You can eliminate chain noise as a possibility. Start with the easiest first.

[@brendonsummerton3509]

@@jonsmotorcyclerescueandrev3538 alright, much appreciated!

[@hansbjrn6008]

Hi Jon. I have a cb 900 Bol'dor from 1981. Haynes manual tell me to adjust cam chain while engine running, but it also tell me that in owners manual it can be recomanded to do it in a differet way- I think with engine not running. I don't have owners manual...Do You have any idea what I have to do, and what is the difference? - Thank You

[@jonsmotorcyclerescueandrev3538]

It should be the same procedure as the CB900C outlined in this video.

[@hansbjrn6008]

ok, thank you 🙂

[@lovingjesus5184]

Just purchased the 1980 cb900c off of AutoTrader. The gentleman had a whole garage full of restored vintage bikes and seem to have a really good reputation. I rode the bikes for about an hour just one time and it was pretty hot out so I don't know if it has anything to do with that but I just noticed that it's leaking oil. Can anyone give me any advice?

[@jonsmotorcyclerescueandrev3538]

Where is it leaking from? It might be a simple fix. With vintage bikes (or used bikes in general), they can develop leaks if they haven't been ridden regularly. Until I've ridden a bike a few hundred miles, I stay local and check it over often. It's similar to owning an antique car.

[@lovingjesus5184]

@@jonsmotorcyclerescueandrev3538 my timing is not the best :-( I'm having a surgical procedure tomorrow on my right arm so it's basically useless and for me to get out and try and figure out where the leak is is almost impossible right now. I appreciate your response and if you don't mind, once I am able to investigate I'll send you another message.

[@jonsmotorcyclerescueandrev3538]

@@lovingjesus5184 Sounds good.

[@lovingjesus5184]

@@jonsmotorcyclerescueandrev3538 good afternoon Jon. Good news. I think I found the problem. It appears that the shifter seal is leaking. I wonder if you could tell me where the best place to get those kind of parts for this bike might be? And is it a pretty easy fix?

[@jonsmotorcyclerescueandrev3538]

@@lovingjesus5184 I would check with Honda first. I don't think it's too involved but I have never replaced that seal before.