'86 Vf500 F Cct Knocks. Safe To Engine To Keep Riding?

[Guest DrJay]

In a post on VFRW I asked about a mild but noticable engine knock and was advised to synch the carbs. Well, I did and there was no change. A mechanically skilled friend said it sounded like a cam chain tensioner noise to him, so I searched U Tube and found 6 videos with good audio of VF500 Fs and 4 of them had exactly the same knock or click that mine has, but a couple of them did not. This to me says that most of the 500s still running have poorly or non-functioning CCTs but those that do have good CCTs are click-free.
I have researched replacing or fixing VF500 F CCTs and it looks like a daunting job, fraught with risk of dropping oily parts into the crankcase, even if parts could be found.
I'm really enjoying riding the bike and have put about 100 miles on it with no change in the knock and have (against general advice) run it up to 10K RPM a few times with no problems. So, what I'm wondering is, how risky to the engine is it to continue to ride it as is, given that I typically ride like the 70 year old guy I am with only occasional higher RPM blasts. I'm leaning more and more to making this bike a long term keeper and have every reason to believe the bike and engine are very sound overall. I don't want to ruin the engine by running it a few hundred more miles just because it is fun to ride now. But I also don't want to spend a lot of time painting and detailing it now if fixing the CCT problem is not realistically possible without major expense and mechanical talent. I have built from bare blocks about 3 small block Chevys 7 Triumph twins, a couple of Nortons and 1 SOHC 550 Honda 4, but am uncertain I could succesfuly tackle a 500 CCT repair, even if new parts were available and affordable.
So, my happy fantasy is that you will respond by saying, "No problem, ride it as much as you want, thoroughly do your homework on how to repair or rebuild the CCT and do that this winter." , but what I really want is your honest thoughts on the matter.
Thanks in advance

Jay

[YoshiHNS]

Have you done a valve check?

If the chain is lose, you are asking for major trouble. The kind of trouble I have two of. I would at least pop the valve covers and take a peak. If you are planning on making this a long-termer, then the proper elbow grease must be applied.

I'm a bit confused though. You say you've done several major engine builds, but you are afraid of replacing a CCT?

[Guest]

Before I even tried to start it I checked and adjusted the valve clearances using the 2 feeler gauge method. I noted that everything in the engine was super-clean, but didn't check anything related to the cam chain since I didn't know about the issue at the time. I am not sure even now how I would check the CCT condition to confirm that that is what is causing the knock.

The only instructions I have found on replacing the CCT were for the first generation 750 not the 500 and involved using new parts, pulling the engine from the frame, using a coat hanger hook device to keep a spring loaded tensioner under control while installling the CCT and numerous warnings about dropping various bits into the crankcase. I'm a decent mechanic, but if there is no way of blocking components from falling into the crankcase with rags during the process it would be nerve wracking. Plus, I doubt if new parts are available and am unsure if repairing used ones is possible.

What have been the bad results of running noisy CCT? It seems that as long as the chain is not so loose as to jump a tooth no serious problems would result. I'm not trying to dodge fixing it if fixing it myself is fesable and should not be put off, just not sure about what is possible and affordable.

The above long-winded background info leads to some specific questions that I hope folks can help me with.

1. Does the engine have to come out of the frame to replace the CCTs?

2. How do I definitively diagnose the need for CCT replacement?

3.Where can I find detailed info on how to replace the CCTs without pulling the heads?

4. Where can necessary new parts be found?

5. Is it usually possible to repair the old CCTs and how does one do so?

Thanks in advance for any and all help!

Jay

[YoshiHNS]

I put the VF500 service manual in the download section. I would start there.

I feel like you will want to pull the engine out of the frame to do the CCTs. Maybe with the F frame it will be easier, but with the C frame, that center beam makes it impossible to work on.

I doubt there are any CCTs available on ServiceHonda or anywhere. I probably could take the ones out of the spare 86 engine I have if need be, but that engine blew up, fyi.

[Guest]

Thanks Yoshi,

I already have the Factory Service Manual, I agree it is essential for many jobs on this bike. For first things first, do you know how to check the CCTs with them on the engine, I think the noise is the CCT but before pulling the engine would want to be sure. Can it be done by pulling the rocker covers and observing cam chain behavior or slack there while rotating the engine by hand?

[YoshiHNS]

I don't know if there is a proper way to check it. I would assume it would be similar to any other tension device. Just rotate it around and see how much slack there is. There shouldn't be much. You might be able to get a screwdriver and see how easy it is to relief the tensioner. If it's really easy, something might be bad.

Maybe someone else knows more.