Adjusting valves on older Honda engine

[buckslayer]

Was hoping maybe somebody could help me out here. I've got an old Honda 3-wheeler (ATC200M) It's got the little, single over-head cam engine with decompression. Can somebody tell me what the clearances should be for the valves? I'm assuming that the front cover is for the exhaust valve - right? Also, I can't remember the procedure for adjusting the cam chain tensioner. Do I loosen the lock nut, tighten the inner screw finger tight and retighten the lock nut? Any help would be appreciated with tuning up a play toy.

 

[JasonJ]

Grooooaaann.
I just so happen to be toiling over a POS Honda XL 175 SOHC. Yeah, the front hole is for the Exhaust the rear is for the intake. These things are the worst. The valve cover actually holds the rockers so clearance can vary greatly depending on the cast of the head, the gasket and torque of the vale cover nuts so try to check the conditions of all that junk before your clearance check. Call your red dealer for the specs or if you want I can give you the specs for the XL 175. I just read the cam chain deal after not being able to find the POS to remove the cam, it was under the shifter hidden by the skid plate of all the sneaky places! Is that what the Trike looks like? If so the book said loose the jam nut and tightnen the nut. Im not 100% now though, Ill try to dig out the book and re-read that part. Its just the poorley translated owners guide though, it has the vale specs in it. Run the best oil you can in that thing with someting like prolong or duralube in it, from what I understand from talking to people about these older Honda SOHC bikes is the oil design and cam/head/valve cover jornal and oil system was poor and leads to early cam and jornal failing. Thats what happend to the one Im working on as well. Actually looking for ward to kicking this bike out and starting the CB 400 Hondamatic thats next,,,, none of these are my bikes!!!!! why do I keep doing this junk for other people???????

 

[buckslayer]

Thanks for the response. What year is the XL175? This is a 1984. Basically the same engine that I had in a 1979 XR185. Unfortunately, I sold the maintenance manual with that bike - should've kept both!! Anyways, it sounds like this engine is a little different than yours. For sure, my cam chain tension adjuster is on top of the cases, covered by a rubber boot thingy.

 

[JasonJ]

Ok, yeah, this is a 75 but they made it untill the early 80s. The dealer should give you the specs for the valves.