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bigtom17

Valve adjustment Questions????

3 posts in this topic

So twice now I have attempted to adjust the valve clearance on my pig and I just seem stupid when I attempt to measure them. First of all I don't know which is the intake and which is exhaust. Second it I can never get a feeler gauge in the gap. I am going to buy the special one today though. It seems that they are too tight but I don't want to adjust because I think I am doing it wrong. :excuseme:It says to turn flywheel CCW 2-3 turns past the "t" mark. Do I use the kick starter to do this or do I manually grap the fly wheel and turn it. How do I make sure the piston is at top dead center, it this done by slowing cranking it, what if I pull decompresser to achieve this, is that bad. It seems like such a simple procedure but I am afraid to tweak them at all. I am sure you guys have done this many times. Throw me a bone. :thumbsup::awww:

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Start here:

http://www.off-road.com/dirtbike/tech/XR650ValveAdj/

Q> It says to turn flywheel CCW 2-3 turns past the "t" mark. Do I use the kick starter to do this or do I manually grap the fly wheel and turn it.

A> Use a socket and ratchet wrench.

Q.How do I make sure the piston is at top dead center, it this done by slowing cranking it, what if I pull decompresser to achieve this, is that bad.

A> TDC? Read article

A> Do not pull the decompressor lever. You will get a false exhaust clearance reading.

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The Motion Pro feeler gauges makes adjusting the valves easier (for me anyways). On the way to TDC, you should feel the compression stroke beginning (piston moving upward & valves closing). At TDC, you'll also notice that the rocker arms are all up for both the intake & exhaust valves. The intake valves are on the side where the intake occurs through the carb (air/fuel) and the exhaust valves are on the side where the exhaust pipes are.

The reason for spinning the engine over a few times is to make certain the auto decompressor mechanism isn't engaged. The auto decompressor mechanism (which is part of the cam assembly) lifts an exhaust valve when the engine spins backwards to minimize the kick start lever from kicking back at you. So if you're spinning the engine over to check your valve clearances and the flywheel rolls backwards while your trying to find TDC, then the auto decomp mechanism has probably lifed an exhaust valve, which means you will not gete an accurate measurement. If this happens, just spin the engine over a few more times to be safe. The article explains things pretty well, but ask more questions if you need to.

Also, make certain that your engine is stone cold when doing your valve checks & adjustments, otherwise it won't be accurate.

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