Need to adjust cam chain tension on an OHC 200cc engine

[jimbob22]

How is this done on the 200cc OHC engines? Pushing 2000 miles now, and things are getting a little loose Thanks...

[ob1]

Post a picture of the left side of the motor, as close as you can while still showing the top of the engine cases to the valve cover. Take the picture from the direction of the foot pegs, so it shows the side and rear.

I may be able to help if it uses the Honda XR200 style tensioning, the picture will let me know if it does.

[jimbob22]

http://members.bellatlantic.net/~vze3sdb7/m15.jpg

The valve tension adjuster is a steel plate on the back of the cylinder.
It has 2 hex nuts, one at the bottom of the plate, the other at the top.
The plate also has a large philips screw in the center.

Cheers

PS: The picture is rotated 90-degrees counter-clockwise.

[ob1]

That would appear to be an automatic tensioner, similar to that on my XR400. I could be wrong.

Describe the noise you are hearing.

[jimbob22]

Noise is very light....barely noticable. My first thought is that it sounds like valve tappet noise. I adjust valves and re-checked. No difference.

I first noticed it about 5 months ago? Has not gotten worse, or better over time.

It is most noticable when engine is at mid-RPM range under slight load.

When engine has no throttle applied (slowing for stop) there is no noise.

Engine under full load noice is not noticable (maybe it is being drowned out by louder exaust note?).

No metal particles in oil (I think honda's chains rubbed an aluminum guide and caused metal in oil?)

Thanks for the help.

[jimbob22]

PS: It sounds like detonation......I ran it on 93 octain and it did not improve. I'm thinking that it is just normal valve noise.
It is the OHC version (not many of these are around) so it's hard to compare it with other peoples experience on the OHV version. Top-end is totally different.

Thanks again

[ob1]

Well, if it is the cam chain rubbing, the sound would be at a much faster rate, as compared to the engine RPM.

Take a long screwdriver, place the handle in your ear, run the motor and place the tip of the screwdriver at different point on the engine. You should be able to track down the noise. It will get louder the closer the scredriver gets to the place where the sound is originating.

If your valve tappet clearances are in order, dont sweat tappet noise, it's natural.

[dlunt]

It can't be any louder than the OHV!
Once mine warms up the sound reminds me of my Mom's old Singer sewing machine.
This is funny (to me anyway) because I always joke around with my buddy that has a BMW R1150R that his bike sounds like a sewing machine when he comes up behind you on the road.
His bike sounds like the "newer" Kenmore sewing maching my mom bought.
:lol:

[fatboy250]

Ok, so how do you adjust the cam chain tensioner on these OHC engines?

I remember on some of the other bikes I've had, they had a "bolt" and a nut. Once you loosen the nut and backed out on the "bolt" the spring tension would adjust and push against the cam chain guide. Once you did that, you would just tighten the nut back up.

Has anyone done this yet? I noticed a phillips head screw? Not sure how this is going to work. Would be nice to have a shop manual or something similar.

PS. I'm am hearing a similar noise as described above when I thottle up under load when the engine is still warming up. I only have 350miles on mine. I think dad mentioned something similar on his.

Jason

[tzrider]

You don't adjust the cam chain tension, it's an automatic tensioner. The valve tappets will rattle a bit and as the engine ages there'll also be some piston slap. Air cooled motors are noisy if you're not used to 'em. Heck, my old Goldwing has enough piston slap the noise sometimes concerns me, but I've taken several long trips on it and it's not caused a mechanical of any kind. Sometimes we just get a little paranoid.

I have the OHC motor, didn't really know it was rare. :lol:

[fatboy250]

Ok, I know it's an automatic tensioner, but there is interval maintenance at like 1000 miles (I think) which it even states in the owners manual.

This is something that I pulled from another webpage http://dirtrider.net/forums3/showthread.php?threadid=13140
http://dirtrider.net/forums3/text/topic/13140-1.html

And from http://www.thumperpage.com/articles/tl125faq.html
About midway down under the heading "What are the common problems/weaknesses with the TL?"

4.) The cam chain adjustment is very counter-intuitive, even if you have access to the Clymer service manual. You have to "unscrew" the tightener to tighten cam chain (manual just tells you to "turn the tightener until resistance is felt"). When I got my bike the tightener was screwed in all the way, resulting in so loose cam chain that it had jumped 2 teeth on the sprocket.

Now does that mean that you would just loosen the philips screw while at idle and maybe loc-tite it in place until future adjustments?

Jason

[ob1]

If it works as I suspect, you loosen the screw, which locks a spring loaded shaft. The spring loaded shaft extends to take up the chain slack. You tighten the screw to lock the tensioner in the new position.

[fatboy250]

Ok for the OHC guys out there. Has anyone done this adjustment? Just looking at it, the starter is in the way and that would have to come off just to get to it.

Jason

[red2003]

Any update on this? I am curious too. Cam chains make a big mess when they break!!!!

[czowner]

OK guys, here it is; if you have an adjuster like the one in the picture at the top of the page it's fully automatic. Take it form me DON'T TOUCH IT. There's a threaded rod and a 12 inch clock spring in there. If you have to remove it for any reason it will pop out to it's deepest setting, to re-set it remove the phillips screw and with a small screwdriver turn the rod clockwise to pull the plunger back. This will need 3 hands with the motor still in the frame.

Jonathan.

[fatboy250]

So there is no need to adjust it ever??

What about the valves??

[red2003]

Sounds like it doesn't need adjustment. The valve adjustment is in the manual that came with the bike. Set engine to TDC, then set valve lash. I am assuming the valves are lashed with the engine cold. Of course the manual that came with my bike was for the pushrod engine, but I assume the valve lash would be the same for the OHC.

[ejcycles]

Hi All
Valve adjustment is on a cold engine at TDC, both intake and exhaust valves should be set at .002-.003 thousandths.

Ride Wild and Fly Like an Eagle! 8O
Bruce

[fatboy250]

Thanks Bruce! Is it better to have these OHC engines closer to .003 than to .002 ? Something I remember reading about them working there way closed or something.

[ejcycles]

Hi Guys
Adjust them between .002-.003 and you'll be Ok. This goes both of these engines, Push-rod & OHC {Over Head Cam}. Valves wear and so do the seats this is why they need to be adjusted. I tighten then at a tight .003.

Ride Wild and Fly Like an Eagle! 8O
Bruce