How do I check my engine compression on 1994 Suzuki dr 350 with auto decompressor?

ErikBennett

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Apr 22, 2013
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I have adjusted the valves and know how to test compression on vehicles. Trick is the engine has auto decompress built into system run by a knock cam. Therefore I can't get pressure built up like normal as well as know if valves are leaking and in need of service. It is difficult to start at first. Has a constant velocity carb that is all rebuilt for millionth time trying to solve start problem. Has good spark. new battery. Book says hard starting caused by low compression. I just need to know how to perform proper compression test. Take out knock pin in cam? There is no manual decompress or kick start on this model.1994 DR 350 SL? Thank you!
 
I would just do a cylinder leak down test! It is much better than a compression test!
 
simples really

you only need to know what the compression is
Put the bike into gear
and with the compression tester screwed in

PUSH BIKE BACKWARDS
!!!
the lifter will not work as the valve train is now working backwards it sucks air in from the exhaust and so it should give you a clear reading.
Wet testing
before you do so spin engine on starter, remove plug add oil turn engine over a couple of times
put in compression tester and then in gear
PUSH BIKE BACKWARDS
You need to crank the engine on the starter to ensure the bike clears any possible contaminants
 
If your trying to test the valves you need a cylinder leak down tester anyway and you can use one of them on engines with decomp valve
 
what is the voltage from bat neg to the positive side of the coil?

if it is a single cylinder then I dont know how you will do that but its correct adjustment must be critical to starting too?
 
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