View Full Version : 200ES Cam Chain Tensioner and Crankcase Pressure
Guggenheim99
01-29-2022, 09:46 PM
I have 2 questions. After getting my 200ES running well, I noticed it had the typical 200cc cam chain rattle. I had seen the video on how to adjust it online so I went to adjust it. Had bike running and warmed up, pulled the cap, screwed the tiny screw in, loosened the jam nut, and when I went to go down then up like DRay shows, the small bolt doesn't move up or down at all. The jam nut was pretty loose. I gave it some moderate force, but did not want to force it and possibly break something. Any ideas on what may be causing it to not move? I plan to pull the motor this winter to do valve seals since it smokes on startup, so I may end up doing guides/chain/tensioner while I'm in there. Unless it's a simple fix. The second question is should you have excess crankcase pressure coming out of the timing cap? I went to check timing once and the pressure was just pouring out so I couldn't check it. Compression is very good and can't pull over by hand without decomp and does not burn oil (only on startup, but that's valve seals like I mentioned previous question) I actually had to route new crankcase vent hoses due to the old ones rotted off, and there's that same pressure coming from the nipple on the crankcase; so I know it's not a restricted hose. Is there another port somewhere else that may be clogged? My 125M doesn't have any pressure when I pull the timing cap. Thanks in advance.
ATC King
01-30-2022, 10:40 AM
What you're getting out of the timing is probably more splash than pressure. The flywheel is whipping away in oil right there. If everything else on the vent is free flowing, it's just what it is, and that's a mess.
I've never had much luck with the factory timing chain adjustment procedure. After decades of use and sitting, I chalk it up to things just being stuck, a weak spring, or any other other possible reason why it doesn't work properly. It probably did when new and near new.
Keep in mind, a chain in need of replacement isn't going to be able to be adjusted to get rid of all the noise and if the guides are worn out, same thing.
My procedure is to get the engine TDC on compression, line up all the timing marks like for adjusting the valve clearance. Inside of that adjustment plunger are small threads, something like an M3x1.00, but I don't remember exactly. I'd have to go in the shop and look. I loosen the locknut, thread the bolt into the adjustment plunger, pull up lightly to adjust the chain tension, and tighten the locknut while holding tension.
That bolt in the top is just a plug, what you need to get a bolt in to is part #6 here. It needs to be a long bolt.
https://cdn.partzilla.com/cdn-cgi/image/quality=50/MTE/d/1/MjAxNDg1Nw-173f1132.png
https://www.partzilla.com/catalog/honda/atv/1984/atc200es-a-big-red/cam-chain-tensioner
Shear forces from parts #10 is all that keeps it locked, and you can probably imagine how those may not work right with decades of sticky oil residue on them. There's also part #5, which most certainly could be loosing it umph and with other sticktion in the adjustment mechanism, can't run uphill like it used to.
How about posting a link to the DRay thing. I can't find the video.
Edit I found the video.
https://www.youtube.com/watch?v=GpoHh9EMhaU
Same way to adjust it as I was saying. He says M3x0.5 thread. If you can't get theat plunger to move it could just be stuck or it may need a harder whack to unset the locking parts. You're going in the right direction though.
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