[smitty55]

Gidday folks. I'm getting a rather loud slapping noise with a cold engine. Not a good sign I think. Once up to temp after a run the noise is pretty well gone so the issue does seem to be temp related. I'm pretty sure it's the timing chain so I'm hoping it's just a tension issue. What I'm wondering is if the tensioner lifter assy that mounts on the outside of the engine is adjustable, or is it supposed to be self adjusting? If it is adjustable is it just a matter of taking out the center bolt and turning the internal shaft? I did watch a video adjusting the tensioner shaft ccw on a trx200 so I'm wondering if it's a similar procedure. If not, what is the chance that a replacement unit would fix my chain slap? Also I see that there are after market manual adjusters available on ebay. Would that be a good alternative?
Tks for any help. I am quite concerned as this noise is quite loud and can be easily felt when I put a screwdriver up against it and to my ear.

Item 6 in this pic




Cheers

 

[smitty55]

Hmmm. Over 60 views and no response after 18 days. Did I offend someone? Don't see how I could have... I did introduce me and my old gal.

Anyway I googled my issue and of course found plenty of threads from this site over the years. So I know the tensioner "lifter" assy on this model is auto adjusting as the chain stretches to maintain correct chain tension. If it's at the full extent of it's travel then the chain and possibly other parts should be replaced with quality parts, not the China crap, and should be replaced before it becomes so loose that it jumps a tooth and causes major damage. As for those aftermarket adjustable ones they don't seem to be a good idea as it's not a proper fix, and just asking for worse trouble. Btw, anyone know why is it called a "lifter assy"? All it does is put lateral pressure against the actual chain tensioner guide.
Now I haven't removed the adjuster yet. It likely has never been removed and I'm wondering if I should have a new gasket at hand or are they good and sturdy? Also, I did see at least one post from a mod here saying how to test chain stretch by inserting the the adjuster assy with shaft extended until contact is made with the tensioner and then measure the gap, gasket included I believe. I don't recall the exact parameters but 1/8" comes to mind for some reason, maybe that was a minimum? I'm not sure now.
So back to this auto tensioner. They seem to be dependable from what I've read, but I haven't found anything about how they do fail. I'm not familiar with the internal workings, movement and pressure of the assy. How much does this unit actually move over the life of the chain, or is it more of a static pressure against the chain tensioner guide? I guess the guides must wear some too but to what extent I have no idea. So I guess my question would be do they get sticky ever? Maybe with a cold engine, and then free up when warm? That would be an easy fix lol.

So to me this still boils down to the fact that the engine noise is predominantly only at cold start at idle. With a bit of choke on you can still just hear it. After a minute of sitting and then a leisurely two minute drive total up the road and back and when I park it the slapping noise is gone so long as a good idle speed is maintained. If it does falter I can just hear it a bit.

So this noise is not present at all when the bike is moving or when the revs are up a bit. I guess my big question would be with these symptoms what would your opinions be on the possible extent of the chain stretch and also what is happening that causes the noise to go away once the engine is warm?

Tks for any replies. I appreciate it.

Cheers

 

[retro]

You're right smitty55, this thread was one that got missed or overlooked somehow. I'm glad you bumped it back up!

I'm thinking your cam chain is probably about worn out like you said... You can rotate the motor to TDC on the compression stroke, then take the tensioner out of the bottom of the jug. The tensioner should extend all the way automatically as you remove it. Poke it back in against the chain guide as you would if reinstalling it... until it stops (is held out by the extended lifter) to get an idea how worn out the cam chain is. Anything less than 7/16" (11mm) space between the tensioner and the jug can become a suspect as a potential noise maker.

Those tensioners rarely stick or fail. A bike that sits a long time with old motor oil in it might stick, but you can clean it up in solvent, re-oil it and they are usually fine.

Changing the cam chain is relatively easy too. The right side cover has to come off (get a new gasket for that) and the rocker cover has to come off. You'll need to be prepared to handle a few stuck bolts in the rocker cover.... a good quality tool set and a hammer impact driver is advised.

If you have any questions share them. We're all ears this time!

 

[shadetree]

sorry smitty55, I some how missed this thread ?, but I stay very, VERY BUSY outside the forums, and I don't get to catch all post ?..sorry. as retro said ^^, your better off buying a new cam chain, please don't take the risk with a manual tensioner !. and yes, the oem tensioner is automatic. other than the cam chain ?, it's posb your valves need checking/adjusting ?. .

 

[smitty55]

Hey no problem guys. Tks for responding. I kinda figure my post slipped through as there were a couple of pretty busy ones on the go. Btw I do have a service manual that I ordered off ebay after I bought it 7 years ago, but the pictures are lousy.

Shadetree I highly doubt this is lifter noise, it's not a high tick. It's like a light slap when it does happen. A good bud heard the noise and first thing he said was cam chain. What I still don't understand is why the noise goes away so quickly after warming up. I get that things expand with heat but what would be changing so much here to get rid of the chain slap?


Retro tks for the specs. I was way off lol. Could you explain to me why the engine needs to be at tdc just for tensioner removal? I believe that's the first time I heard that mentioned. Obviously I don't understand the internal workings of these engines enough at this point. Like how do I know for sure I'm on the compression stroke? About the most I've done with small engines is the odd carb kit over the years and popped off the odd flywheel the good old fashioned way. Best thing I did was install electronic ignition and a switch on the old briggs 8hp that runs my 70's vintage super split. Hasn't missed a beat since.

I'm sure I'll have many more questions including when it comes to cam chain and other parts purchase from Canada. Tks for now guys. I'll be back.

Cheers

 

[shadetree]

tick until warm up ?, I would say its because your oil hasn't ran through the motor would be my guess ?. but !, piston rings and valves are lose when cold ?, when they warm up, they expand, sooo..your call. still, a new cam chain is in order, I use D.I.D. brand, nothing but them.

 

[retro]

Retro tks for the specs. I was way off lol. Could you explain to me why the engine needs to be at tdc just for tensioner removal? I believe that's the first time I heard that mentioned. Obviously I don't understand the internal workings of these engines enough at this point. Like how do I know for sure I'm on the compression stroke? About the most I've done with small engines is the odd carb kit over the years and popped off the odd flywheel the good old fashioned way. Best thing I did was install electronic ignition and a switch on the old briggs 8hp that runs my 70's vintage super split. Hasn't missed a beat since.

On a single cyl OHC motor I always crank the motor over by hand to TDC on the compression stroke before doing anything on it valve-train related. Whether I'm loosening the valve lash adjusters before taking the rocker cover off, or in your case... yanking the tensioner out to check for chain wear, I put the motor where both of the cam lobes are facing down (not on either cam lobe ramp) so that a valve spring cannot push back on a rocker and rotate the camshaft backwards on me... and possibly ruin my day or otherwise leave me feeling really dumb. Its a "best practices" sort of habit.... I got a gazillion of 'em! Picked 'em up over 50 years+ attendance in the-schools-of-hard-knocks. Your experiences (and luck) may vary...

To find TDC:
Take the spark plug out of the head, put it back in the plug wire boot and lay it on the head somewhere so the plug is grounded.

Take the two plugs (large flat blade screwdriver) out of the left-side cover. Use a socket on a short extension with a ratchet thru the largest hole (in the center, or the rear-most hole) and crank the motor over counter-clockwise (when viewed from the left side of the motor) until the "T" mark on the flywheel lines up with the index mark inside the smaller (forward-most) hole on the compression stroke. You can stick a finger over the spark plug hole as you turn the crankshaft to sense the pressure escaping... that is the compression stroke. Continue turning the crank slowly until you see the "T" mark line up and stop. Alternatively, you can take both valve covers off and watch the rocker arms (or cam lobes) to find the compression stroke. You can now work on the valve-train.... you can check the chain, readjust the valves... or take the top end of the motor apart. The service manual covers all of this more thoroughly...

Have fun!

 

[Goober]

Sorry never saw this post could be a lot of the viewers couldn't answer with certainty. Not something I have sperience with--would have to let the boys at the shop do for me. And then I have to give them $400��

I would think the chain slapping noise quiets after running cause now you have a fresh layer of oil on the parts.

Oh btw buy a paper copy of the manual much better pics

 

[marlinman]

I know this is an old thread, but I have the exact same bike, with the same noise, but all the time. Have adjusted the valves, but made no difference. I saw a mention in this thread of D.I.D parts. Who is that, and would they still have the chain and sprocket still in stock?
The bike has some other issues I will start another thread on later, but this chain and sprocket are a do or die for this bike.

 

[Eric the red]

Does anyone make a manual cam chain tensioner for these old hondas?
That's the easy fix on dirt bikes with noisy stretched cam chains.