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Runs rough after valve adjustment

13281 Views 10 Replies 5 Participants Last post by  bostthehause
I have a 1984 Honda TRX 200. It was running fine until I decided to adjust the valves on it because it hadn't been done in forever. I consulted the owner's manual and followed the valve adjustment procedures step for step. I aligned the two timing marks to make sure that the engine was at the top of the compression stroke. Once I had the marks aligned, I then wiggled the rocker arms by hand and they were loose, which would mean that the engine was indeed at the top of the compression stroke. I then adjusted both the intake and exhaust valves to the specs recommended by the manual, which was .05mm(.002in). After I put the quad back together, it was difficult to crank. I did eventually get it cranked and it idled fine. It also runs fine at lower rpms, but at upper rpms it loses power and runs extremely rough! It spits a lot of white smoke out of the tailpipe when it is running. Also, the quad has a compression release lever, which is supposed to make it easier to pull crank. After the valve adjustment the compression release lever no longer works. The lever won't stick at the top like it is supposed to. Does anyone have any idea what could be wrong with it? I am out of ideas. Any help will be greatly appreciated! Thanks.
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I would start by looking at what is wrong with your decompression switch. If it worked before and now it doesn't, it's probably directly related to your problem. Pull off the inspection cover on the exhaust side, and look in there with a flashlight while moving the decomp switch. Try looking in while slowly turning it over too.

Another thing that comes to mind but may not be relevant. I used to have a 250sx and every time I flipped it, it would run like crap until I cleaned the carb. Has your bike been upside down lately?
You are correct. The decompressor switch on most bikes just holds down the rocker arm on the exhaust valve until the cam actuates the valve and clicks the decomp off. Like I said, take a look through the inspection cap while moving the switch. It is a simple system and you should be able to see what's going on in there if you crank your neck just the right way.

Keep us posted

Found an exploded view of your cylinder head if that helps you any.
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