Jump to content
Sign in to follow this  

83 XR200R intake valve adjust has me scratching my head?

Recommended Posts

Just got in a 1983 XR200R (two valve, one carb) to replace my 13 yr olds dr125 he just sold and was going through some things on the bike before it's trail ready. I was checking the valve clearances and noticed that the intake valve had not clearance and so I backed it out to spec and noticed that there was no play in the rocker arm at all.. Usually I can just wiggle the arm vertically and hear a little tap. Just for kicks I backed the screw quite a bit to get a bigger gap and the rocker arm still did not move down. So I screwed it back down to spec and am running it this way. I'm not new to valve adjustments so I'm pretty sure I know what I'm doing but this is kind of weird. The bike idles and runs fine. What could be going on to cause this and should i be concerned?

Share this post


Link to post
Share on other sites

I would be a little concerned. When was the last time it was ridden and can you see any signs of rust or water contamination around the valve rockers, looking inside with a torch.

If you are able to remove the cover and inspect the rockers then now would be a good time before a long ride on a your new purchase. Sounds like it is bound and could cause some issues if it it wearing away on the aluminium cover or another component. They are not hard too repair and should always be easy to move.

Share this post


Link to post
Share on other sites

The bike was ridden all along by the prior owner. I did find the oil contaminated with gas and was pretty thin. I changed out the oil and cleaned up the carb, replaced float valve etc so there should be no more leaks. I will probably take off the valve cover to inspect before too long just to make sure nothing is binding.

Share this post


Link to post
Share on other sites

sounds like you needed to turn it over 360 degrees more on the crank

cams off 180 degrees

2 turns on crank = 1 turn on cam

Share this post


Link to post
Share on other sites

sounds like you needed to turn it over 360 degrees more on the crank

cams off 180 degrees

2 turns on crank = 1 turn on cam

I took off the head and the intake valve was so worn out it caused the stem to stick too far up. I got quote of $150-200 to redo the head. I'm planning on getting a good used head with tested valves from an ATC185. Cheaper and more plentiful than an Xr200R too.

Share this post


Link to post
Share on other sites

You can exchange the exhaust and intake rocker shafts which will turn them to a fresh wear surface.

Any two valve125/85/200 head will do. The XR cam is the most aggressive.

To elaborate on previous posts; only one of the two TDCs is good for adjusting valves. the rotor should be on a "T" or "F" mark and the advance mechanism should align with the CDI sensor; this is TDC Firing or Firing position when both valves are closed.

Share this post


Link to post
Share on other sites

Will I have any problem using a 185 head on the 200 cyclinder?. Which top end gaskets do i get 185 or 200 or larger? Can i use this configuration without a problem? I will be boring out the 200 head to 66mm to accept a wiseco piston.

XR200R Valve cover

ATC185 head

ATC200 cylinder

Share this post


Link to post
Share on other sites

All of the two valve heads (incl CRF150/230) have the same stud spacing so head gasket is determined by bore size. The late model XR200R head gasket is used on the CRF230. All of the cylinders have the same liner OD and spigot size, I have a XR185 cylinder with a .5mm oversize piston on one bike and a ATC200 big fin cylinder with a 66mm bore on another. Just do a check to make sure the head gasket bore opening is big enough for the piston. :bonk:

Only possible problem is cam bearing journal alignment when mixing cam covers/heads because Honda bores the journals with the cover on the head and sells them as a matched set. Have said that I've mixed units but check for a mismatch of the journal surface at the parting line and that the bore diameter is in spec, then check for free turning with the cam installed. Have said that be aware that the cam bearings always seem too loose, compare journal size of the XR200 combo to the XR/ATC combo.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...