I have a 1993 LT80 that I purchased as a set of two from a friend. One runs fine the other I was told was run out of injector oil by his kids. My friend stated the bike started again after oil was added. I took it home and pulled the cyl off and honed cyl and replaced the piston and rings with suzuki stock bore. Carb was removed and rebuilt with new kit. All passages were cleaned and new jets and float needle and seat replaced. The problem comes when I try to start it. It will only start when I put fuel into cyl. Once I do this, it will start and stop fine unless it sits for a while then its back to priming the cyl. again to start it. Checked fuel valve and installed new diaphram but unit still should start on prime. Any suggestions? I'm becoming baffled.

 

Welcome to the forums.
Once the rings seat, it'll prolly have enough pull to get the fuel in.
In the mean time, try using 2 fingers in front of the carb (or squeeze the rubber) to hand choke it.
This happens.

 

Thanks for the info. I've never had this problem before. I read a few threads re: piston orientation. Could I have installed piston in backwards, ie: arrow towards front? Would this affect the fact that it wont start/ pull fuel in and only run?

 

The arrow goes toward the exhaust. This is important.
I'm not saying that this will fix the current problem, but it will eliminate any future problems caused from the ring ends scoring the cylinder.