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xr 350 compression issues

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hello i just finished putting my lovely xr back together (new piston ,rings headgasket etc.),before i put the engine back in the bike iit had alot of compression, i put the engine back in the bike and the first few kicks lots of compression, i hooked up the cables for the decomp and ...very little compression,so i un hooked the cables, nothing changed same thing???

i dont really understand excatly how the decompression works maybe i did something wrong on reassembly

thanks!

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Quick test; open up valve adjuster caps, bring flywheel around to TDC [ T] mark and all the valves should have some free play. Adjust all valves and decompresser while at TDC, check your manual for specs.

Decompresser has a cam on the right exhaust valve that holds it open just a hair on the compression stroke when pulled. Check adjustments per manual.

If I remember, there should only be a little bit of free play 5/16'' @ TDC but I don't know about the 350, sounds like it has a cable to the kick starter like the older xr250's

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I recently had my xr 350 ('86) split in half and put it all back together with new rings. Kicking it through its cycle felt really weak to me in comparison to what it used to be (trouble finding where TDC was as oppsed to before where I had to use decomp lever to pull it passed TDC). I had other probs and it wouldnt start so I kicked it 40 hundred million times and stil the same. Once she was fixed (something unrelated to the compression) and started the compression came back to what it once was

EDIT: I think it was something to do with or down near the pulse generator and apparently I had it on backwards, something marked with outside on it

Edited by MrNoodle
further detail

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