yamaha golf cart issues

[mysticmissle]

Just picked up this 1993 g9a cart. ran awesome for a few weeks. came home last nite, after kids took it out,without my supervision and all of a sudden it no longer runs. battery will push cart around a little, but no power. clutch looks like it moves in, i checked plastic rollers in spider and they look almost unworn. It has spark, if i put my finger over the hole it has compression, and i took the carb apart and cleaned it and it looks ok. there is fuel to carb for sure. watched fuel pump cycle, with line off. only thing im thinking is timing? does this thing have a timing belt? any ideas? thanks

[sho305]

Fuel, spark, compression...hmmm. They can foul a plug and it will still spark, especially if the airbox lid is off that makes it lean and they run poor and can foul them. The plug will look good yet. I use the plug for the newer yamaha, the 2, bpr2es or whatever the letters are. The G9 takes the 4 iirc. You can pull the boot just off the plug and it might make it spark, mine would then run with a bad plug. It is a pain to get that airbox on right, the rubber straps are pretty cheap though.

The ignitor is like a CDI its under the fuel pump on the tank. They don't go bad often, best to swap it with another before you buy they are pricey. They advance the timing as rpm rise. There is a pulse pickup coil under the flywheel.

Wiring issues are common on these, about the only common problem, but cheap to fix. There are fuses on the fender behind the battery, check all ground wiring the frame is not ground on these. If you put lights on them you have to ground them or they can screw up the wiring or blow fuses. Check connections, however you should not have spark if the ignition is dead.

[DOOmsman]

Did they bash the exhaust or back it into mud and plug it?

[mysticmissle]

figured it out. apparently whatever compression i was feeling must have been the exhaust valve sucking in/pushing out in because the other push rod was just sitting in there! must have been loose. I reset it and have been drving it all day. thanks guys.

[mysticmissle]

Update, it is still doing it. It is the intake valve either hanging in the guide or the spring is week. it will run for a little while and then push rod jumps out. What is proper way of adjusting valves? It always seems to fall out when you shut it off not under power. thanks guys

[sho305]

When its cold you set them to .004" with a feeler gauge. Tighten it down then lock it and check it, it changes when you lock it down. When you put the rocker cover back on make sure its sealed because oil will drip down to fins and plug them with dirt inside the cowling. You have to find TDC make sure you are not on the compression release I think it has. The valve must be shut when you set the lash and not moving (off the cam lobe). Check it and turn it over then check again. Piston up and both valves up and not moving is TDC.

[mysticmissle]

i pulled it apart and did a quicki valve job on it. 2 days later seems fine. it had a burr or tight tolerance o the upper part pf the guide. I took the edge off it, stoned the head and lapped the intake real quick. 3 hrs start to finish :) seems to be good now. although i do need a new valve seal due to monkeying it up taking it off the head. just get a little oil burning after you shut it off. no smoke. I did a compression test it will go to 170 if you crank it enough. got 15mph on gps with me and kid in it. about 300#s total.