1997 G16 Yamaha cranks but won't start

[logan1211]

Hey all, been reading these forums like mad the last few days trying to narrow this down.

I've got a 97 Yamaha cart that I took in on a trade and started tinkering with. When I got it, it wouldn't start. Gas looked and smelled good. Would just sit and crank, no fire.

Looking at it some more, I realized the previous owner had the vent tube off the valve cover to the fuel pump and the crankcase vacuum tube was sitting there disconnected in the rear. I connected the valve cover vent to the nub on the front of the airbox, and the crank case vent to the fuel pump

Started it up, choke, boom! Fired! Awesome. Drove around the yard a while seeing how she did. Stopped a few times for 10 minutes, drove it again. All was well.

Well about 3 hours later I went to show my wife, and it's back to doing the same exact thing. Just cranking; but no fire. Thought I had it.

I've verified I've got
1. Air
2. Fuel (pumping when carb line disconnected and cranking)
3. Spark - just verified saw spark when grounding plug removed

I would think this means my next steps are digging into the carb for a good cleaning? Previous owner said it had a new carb put on like 2 years ago. No idea of manufacturer though. Appreciate any input!

[CAMPERCART2013]

If it was running and now it is not i would try to verify GOOD spark and fuel. Dynamic spark tester or timing light. And if it's been sitting then if it was me I'd at least tear carb apart and clean, rebuild if necessary

[cgtech]

Spray a shot of carb cleaner down the carb to verify the carb is actually delivering fuel. Fuel coming out of the hose does not necessarily equal fuel being delivered from the carb. Also verify the throttle blade is opening. Both can be done with the air box in place, but will need to remove lid to spray carb.

[1arunem]

Maybe carb sucks up trash and carb is not delivering fuel into the combustion chamber.. A small shot of starting fluid will help diagnose this.