Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: krez on August 15, 2012, 02:21:55 PM

Title: cannot start pw80
Post by: krez on August 15, 2012, 02:21:55 PM
looking for some advice, I have a 2000 pw80.  I installed a new wisco piston .010 over, new gaskets, a new reed valve.  The bike still won't start, when I kick the bike over gas actually spits out the front of the carb.  Any suggestions would be apppreciated.  Compression is only 55lbs
Title: cannot start pw80
Post by: xandyx on August 15, 2012, 02:29:26 PM
is there a spark?

maybe it's overfueling, split the carb and check if everything looks fine.
Title: cannot start pw80
Post by: cnrcpla on August 15, 2012, 03:19:47 PM
Do a spark check, if it is sparking a nice bright blue then move on to the carb.
Title: cannot start pw80
Post by: Logan Dewey on August 15, 2012, 04:06:57 PM
I would say replace some of the possible issues cheapest to most expensive, starting with a spark plug, then eventually if you try alot and it still doesnt start, I'd say get valves checked. if those things have em. :)
Title: cannot start pw80
Post by: cnrcpla on August 15, 2012, 05:25:54 PM
A pw80 is a two stroke. It has no valves. Two strokes use ports. Google an engine animation of a two stroke to get a basic understanding of what happens within a two stroke engine. The only valve two strokes have are the power valves and I don't think this bike has one. Not to meantion I don't think many members on this forum will be trouble shooting with valves   ;D one of the many reasons why I ride two strokes, valves can be a pain in the arse.
Title: cannot start pw80
Post by: Stusmoke on August 16, 2012, 01:07:10 PM
Quote from: cnrcpla on August 16, 2012, 12:25:54 AM
A pw80 is a two stroke. It has no valves. Two strokes use ports. Google an engine animation of a two stroke to get a basic understanding of what happens within a two stroke engine. The only valve two strokes have are the power valves and I don't think this bike has one. Not to meantion I don't think many members on this forum will be trouble shooting with valves   ;D one of the many reasons why I ride two strokes, valves can be a pain in the arse.

Totally false: Valves ARE a pain in the ass, not just can be a pain in the ass :P
Title: cannot start pw80
Post by: riffraff on August 17, 2012, 07:09:55 AM
" The only valve two strokes have are the power valves"

Don't forget the reed valve   ;D
Title: cannot start pw80
Post by: cnrcpla on August 17, 2012, 05:39:55 PM
Well yeah those too but they are a little different  :P
Title: cannot start pw80
Post by: SachsGS on August 18, 2012, 04:46:49 PM
Typically you need at least 100PSI for an engine to run. I've had Yamahas run at 80PSI but at 55 she won't start.
Title: cannot start pw80
Post by: metal_miracle on August 18, 2012, 09:27:35 PM
1.  If your bike have reed valve i would check those.

2..  And if your petrol is old, you can kick til your blue in your face

3...  Also try removing your exhaust it it my be blocked
Title: cannot start pw80
Post by: eprovenzano on August 20, 2012, 02:34:48 PM
Just a thought, could the piston be in backwards?