Cam chain tensioner 1986 VFR700F

Driving one day ~50mph and click, engine rev'ed itself up to 10kRPM, and ever since, I have this clicking/ticking/tapping noise. I've driven it about 3 more miles further after that, to get home.

After some research, I'm thinking it is a cam chain tensioner problem... I think it is the front one (which is the more involved one... yay...). Here's an audio clip of how it sounds like.

If I am incorrect, stop reading and advise!

If otherwise, after more research I think I want to go with a manual CCT. Do you guys know which MCCT will fit my 1986 VFR700F? Or will any modern APE/CRU MCCT work? I'm thinking to might as well replace both together. Some ACCT vs. MCCT debate welcomed.

I'm planning on referencing this thread, and this to aid my quest.

I miss riding it already! Trying to get this fixed ASAP!
Thanks!
Joe

 

CLICK-CLICK-BOOM!

After some research...

you are kidding right, you do know there is no cam chain on a VFR?

 

me an my damn compooter bike got 2 of dem!

 

The audio sounds like a gen 1, how aboot a pic to clear things up. hoto:

 

That doesn't sound good, but an 86 has gear-driven cams = no chains, maybe exhaust leak or valve? :unsure:

 

Btw here is the manual I refer to. I know, it is for a VFR500F. But nowhere can I find one that is for VFR700F... It is the same year and everything looked the same when I was doing electrical work a few months ago.

This manual has a section for cam chain and tensioners...

@fredsncoma do they sound like that? the sound does seem to come from the top & front end of the engine. From all the youtube videos, the sound sounds similar to a cam chain slapping.

 

Yep. Time to pull the side fairings off, get a stethoscope, and figure out what area the ticking noise is coming from.

 

Should be easy to locate as loud as it is.

 

No crap. But it certainly is NOT a cam chain.

 

i know, and i feel sorry for ya

Real VFRs have geared cams...lol

 

Something smellsa funny here !

Try removing the fairings, radiator, and front valve cover for inspection. If you don't find something wrong there, proceed to rear valve cover.

 

Hello! Sorry for the MIA. I finally have time to work on the bike!

I got the front cylinder head cover off per the manual. Now, I have a few questions:
1. Each cylinder marking on the crankshaft is confusing. There are 3 markings per cylinder number, and are marked with "T1..4F" (the manual is too pixellated, so the diagram in there is useless). Please see the attachment and advise on which marking (a, b, or c) do I line up for TDC?
2. When I go to measure the valve clearances, the exhaust and intake sides need different clearances... Problem is, I am not sure which one is which (x, or y). The below image shows cylinder #4. Please advise!

Thanks!

 

can't remember on the timing marks w/out looking at manual, but it should be pretty clear in there. as for valves, ex are on the side the exhaust comes out so (x) in you pic and intakes are the carb side of the cylinder, so (y) in you pic. good luck

 

Thanks fredsncoma.

The manual literally only says:
1. Line it up to the T1 mark.
2. Make sure # piston is at the TDC on the compression stroke (with pixellated picture).

Each piston has three markings... I WANT to say I line it up to the (a)-marking in my image, as it says "T#", but there is an awkward space between the T and the #... so it seems to read "T 2F"... The F (assuming that means front, but there's no "R") and the unmentioned II confuses me.
a. Long line
b. I
c. II

 

T means Top Dead Center for that particular # cylinder, e.g. 1,2,3,4.
When you adjust the valves for # 4 you will use the T4 line, for #3 use T3, etc. It's not a critical alignment, they are just helpful guide lines to get you where you need to be for each cylinder.

But you also have to make sure at TDC that the piston is on the Compression stroke for that cylinder (both valves closed) and not at the end of the Exhaust stroke. The lobes of the cam will be pointed down toward the piston at TDC of the Compression stroke, whereas they will be pointing up away from the piston at the end of the Exhaust stroke.

F means the Firing position, that is when the spark plug fires for that cylinder. Those marks are used with a timing light when adjusting the ignition timing.

 

I love your answer!

Yeah... I figured (a) is the TDC... Good to know for F.. What might the II mark be?

Also, I will check the cam lobes... I was going by the feeling (and sound) of pressure leading up to the T mark for getting the compression stroke.

My poking around (at the right combinations) last night seem to show the #4 clearances were less than the spec 0.005/0.007 in... Which I think is the culprit of the (RPM matching) loud knocking sound I was getting.

 

You can easily ignore the timing marks when checking clearances !! Simply measure clearances while the high point of the cam is generally pointing AWAY from the valve.

Setting cam timings, checking ignition advance, both require close reference to the exact marks, but valve checks do not.

 

Take the plugs out, it will be easier to turn over. Plus you'll want to put new ones in after doing all this work.

Ignition timing can be advanced or retarded with respect to TDC. The || line is the most advanced timing line and the F line is the retard position.

If #4 was too tight then it wasn't closing completely during combustion and could be causing all the racket.

 

So I checked #2 and #4's valve clearances, hoping that might be it (since the sound seems to be coming from the front). Before my adjustments, 6 out of 8 positions were too tight, that my feeler tool didn't even budge. So now there are slight drags on all 8 there.

Sound is still there, however. I took a video of it running, traveling back and forth between the front and back. I don't have a stethoscope, but the sound seems to be coming from the front. Any more ideas?

No, I have not yet inspected #1 and #3. I hope this is not a piston issue (per 12-2 of the VFR750F manual).

Thanks.