250-500cc wr360 no power

[starman981]

hi just wondering i have a 1992 wr360 does anyone know the compression readings of this motor ive done 1 on mine and its a 180psi acording too my tester but my main question is is the piston at tdc meant to be level with the top of cycinder? mine is 1.25 mm from the top is this normal as every pther 2 stroke ive ever worked on the piston is level with the top of the cylinder at tdc ????

 

[2premo]

you check the squish area to determine the piston height and set it with gaskets under the cylinder

 

[2premo]

the thread is titled "wr360 no power"
what is your bike doing that brings up your question??

 

[2premo]

http://www.husqvarnamotorcycles.com.au/files/editor_upload/File/Manual/manual_2002_wr_cr_250_360.pdf

go to page 200 to read how to check correct squish
FYI all 360's are the same basic engine design so this will work for checking

 

[starman981]

well it dont have any power it wont wheelstand without the clutch it doesnt really spin the wheel and i cant do a sqish band test as the piston doesnt come up high enough

 

[starman981]

would having too large a squish area cause it too have no power?

 

[2premo]

checking the squish area is done when replacing the piston
180 psi should make power, probably have some other issue
how long have you had the bike?

 

[starman981]

well i just had the cylinder resleeved with new piston and rings ive had it about 6 months its never really had the power it should have

 

[2premo]

did you do the work yourself or take it to a shop?
did you own it before the sleeve and piston?
if you did the work did you adjust the power valve?
did you do the top end only or was the bottom also worked on?

 

[rancher1]

You have good compression so the squish area is not the problem. How about a plugged muffler ? Timing ?

 

[Kyle Tarry]

i cant do a sqish band test as the piston doesnt come up high enough

Did you read the procedure in the manual? There's no reason that you shouldn't be able to do the test.

An easier test (which doesn't require removing the cylinder or the piston) is the solder squish test. Some good details here on the RB-designs page:

http://www.rb-designs.com/rb_designs_llc_017.htm

Based on the 1.25 mm number you gave and your compression test, it doesn't sound like the squish is off, it sounds fine.

I'd be questioning the jetting if a fresh rebuild didn't make good power. Checking timing and for a plugged muffler are really good tips too.