[img]i/expressions/face-icon-small-shocked.gif[/img] try taking the air cleaner off and put your hand over the hole this will choke the eng. out but it helps you to know if your getting fuel plus if the is any small chuncks of dirt or gunck in the carbs it will pull it thuogh

 

Good point daatv.

 

you must use 2 strokes and 4 strokes carb cleaner only as well.

 

FYI for anyone following this diagnostic... the cylinder is cracked. Found it after wasting about six hours of relentless checks. I'm suprised though, it's got 110 lbs of cylinder press. cold. So can anyone tell me why a two stroke won't run w/o crankcase pressure?... I know this to be true, but don't know why.

 

A 2-stroke needs crankcase pressure because if you follow th fuel system the fuel mixes around the crankshaft and then is pulled into the cylinder via the ports. your fuel also lubes the crank and rod bearings in these beasts, thats why ratios are so important

 

Primary compression or crankcase pressure is created on the piston down stroke, this pressure is what forces the fuel/air mix up through the transfer ports to fill the cylinder. If the engine doesn't have this it won't run. Do you have the cylinder off the engine? What does the base gasket look like? Where is the crack in the cylinder?

 

Don't have the cylinder off yet... basically one of the front flanges where the cylinder bolts down is cracked off. The crack goes around the corner. Some of my buds tell me this can be welded... is it worth welding, or should I opt for a new cylinder?... where is a good place to price a cylinder? The piston is oversized, as well. I suspect this is a result of running the machine at WOT in deep snow for period of time. I know this in not a proper fix, but would it be worth JB welding (epoxy) to get crankcase pressure and run it like that for a while?

 

Rick Ritter can weld that cylinder up for you.He did one of my friends .

 

CED - checked out your pix... sweet quads... how come it's common to cut the plastic off when dune riding? I've never been

 

Well at one point i still had some rear fenders ,then i was run over by a dune buggy.It cracked one side of the rear fender,so i just cut the other one so that it wouldn't keep on cracking.I will get some new ones eventually.We have a bunch of polaris guy's headed to Lil Sahara ,Okl. you should try and make it.May 15th weekend.