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Pressure build up in DT85?

Toddys suzuki

New member
My 1983 suzuki DT85 is not turning over. I have pulled the head off and everything seems fine with the power head. no signs of scoring or anything. the cyclinders move fine with the head off but with the head and plugs in there seems to be a building up of pressure that prevents them from moving. im thinking this could be a blockage in the exhaust? how do i check? any ideas? i dont really want to pull the lower leg off if i dont have to.
 
did you do a compression check before you pulled the head off?could you not turn the motor over by hand,before removing head?
 
One of the only things that could cause that is something protruding down into the cylinder, like a too long spark plug that is preventing the piston from coming up all the way.My advice is to put the head back on and do a compression check.
 
done compression test 135, 135 and 110. no i cant turn the motor by hand with the head and plugs in. im leaning towards a blockage or valve issue. thoughts?
 
does the motor stop solidly,like its hitting something when you turn it by hand?did you use a power bar with socket on flywheel nut.Ive even turned over big diesels by hand,so a 600 odd cc two stroke shouldnt be too hard.when you started it originally with the starter motor,or tried to,what did it do?
 
no it gradually gets stiffer and stiffer and eventually stops. it turned over a few weeks back but only ran for 10-15 secs then stopped. i have tried turning it over with rope around the flywheel but makes no difference. it really feels like pressue is building up until theres just too much back pressure.
 
no it gradually gets stiffer and stiffer and eventually stops. it turned over a few weeks back but only ran for 10-15 secs then stopped. i have tried turning it over with rope around the flywheel but makes no difference. it really feels like pressue is building up until theres just too much back pressure.


That's normal, it's called compression, that's how engines work !!! How are you trying to turn it over ?? Are you saying the starter won't crank it??? How did you do a compression test if it won't turn over ??
 
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