Need help 89 650sx wont stay running

So the story goes, i bought it last year painted it and swapped out a couple of things. Got rid of the 28mm carb and went with a 38mm kehin. Swapped pipes to a westcoast, and ride plate. I checked compression twice once when i bought it and the second recently. Both times and both cylinders are around 170. Problem is i can only get it started with primer shot, otherwise no good. Wont even run past a couple of seconds. tried a couple different carbs to insure that it wasnt the carbs. ive replaced all lines, checked the pick up, new cdi etc. i have run out of ideas and im beginning to become frustrated with it. Oh yes the reeds are new. Any ideas would be greatly appreciated. By the way it is kawasaki 89 650sx.
 
If it starts with a primer shot, try priming it slowly as it is running to keep it going. If it does then you have another issue. If it stays running it is fuel related: carb, fuel selector restriction, fuel filter or fuel pickup.
 
Thanks for the info. But I'm probably going to take it to blowsim since they are close to me. Its been to much of a headache. I routed a line directly to it and no fire. Even gravity fed it to eliminate fuel pump issues; beings I tried 3 different carbs that I know worked prior. Bypassed selectors and pickup tubes. Replaced just about everything and no go. Haha
 

simofx-1

freeride
Location
new zealand
i had this problem when i got my engine back from a rebuild, i found out he had put the reed gasket around the wrong way cutting off the air flow over the pulse fitting(take your pulse line off the carb and suck on it to see if you can draw air,it wont run if no air gets thro),
if you changed gasket when you did your reeds it could be this.
 
Pull the fuel line off feeding the crab. See if the fuel pump is pushing fuel to the carb.
 
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