Marathon Engine troubleshooting

[SamCarroll]

well, i ran the wire down the swingarm, removed the oil reservoir and the pump. Pre-mixed the gas, pushed the gas out and primed the engine. It just sits there and sputters like it wants to start but just doesnt catch.
Anything else i should try? This is becoming aggravating because it wants to but just isnt starting.

[BrewCityMusic]

Hmm ... alright, let's keep moving along here. First, are you sure you have compression like you should (130lbs+) ? If so, let's try this: unbolt the muffler from the exhaust pipe and leave it so there is a decent sized gap between them and see if that helps it start (muffler could be plugged, even a partial obstruction will keep the cart from running right).

If that doesn't help, you *might* want to think crank seals, if they went bad from sitting it would keep the engine from drawing enough gas to run (although correct me if I'm wrong, Dave or ? but if there's enough vac to make the fuel pump work, then technically there still should still be enough to run, right?)

[SamCarroll]

I kept messing with it and now i have it to where the exhaust puffs like its just about to start then still doesnt. It still backfires from time to time but i checked the grounds and now the starter sounds like its healthier so it may have been a weaker ground as well.

Ill unbolts the pipe from the exhaust and see what happens.

[Dave Box]

Sam,
BrewCity is correct with regard to the crankcase pressure. If you are getting a good healthy output from the fuel pump then the crankshaft seals should be good. Try running without the muffler and let us know.

[SamCarroll]

it just keeps backfiring with the exhaust open, smokes a little, sputters as the starters going thrn backfires or doesnt do anything.

[SamCarroll]

it just keeps backfiring with the exhaust open, smokes a little, sputters as the starters going then backfires or doesnt do anything.

[SamCarroll]

i quit for the night. I cant figure this engine out. It sucks because i have plenty of knowledge in engines and what not in cars but i dont know a **** thing abut this cart. It backfires constantly, it gets fuel, the starter goes, the gas is premixed and lines are primed.

I noticed whenever it tries to start the carb pushes air out. to me that seems backwards? ive used starter fluid spray, ive used some lighter fluid in the spark plug hole to try to force ignition spark.

Im so close to giving up and taking it to a shop here locally.

[Dave Box]

Sam, I wonder if the timing ring that holds the pulsar on has slipped and your spark is way retarded. It's a long shot (actually it's a very,very long shot) but the test is simple.

Put it in reverse and try to start her up. Does it sound the same, different, maybe even start up.

Blowing air out of the carburetter is clearly not correct. The only way that I can think of this happening is if some dirt has fallen into the reed valve and is holding it slightly open. Convesely this would kill your crankcase pressure and stop the fuel pump working. Are you positive that you are getting a generous pulsing jet of gasoline from the pump as you crank the engine?

Best
Dave

[SamCarroll]

Originally Posted by Dave Box

Sam, I wonder if the timing ring that holds the pulsar on has slipped and your spark is way retarded. It's a long shot (actually it's a very,very long shot) but the test is simple.

Put it in reverse and try to start her up. Does it sound the same, different, maybe even start up.

Blowing air out of the carburetter is clearly not correct. The only way that I can think of this happening is if some dirt has fallen into the reed valve and is holding it slightly open. Convesely this would kill your crankcase pressure and stop the fuel pump working. Are you positive that you are getting a generous pulsing jet of gasoline from the pump as you crank the engine?

Best
Dave

Ill try to put it in reverse and attempt to start it. I replaced the fuel pump and ive pulled the gas line after several attempts to start and it had a good amount of gas in the line.

[GoTeeMan]

Just for thought, pull the plug wire and check the condition of the spark should be blue/white. If it is red/orange then you need to check the coil, ohm the plug wire etc make sure you are getting good clean spark. Check the state of the battery, neighbor with a par car tired everything to make his cart run properly and it turned out to be a bad battery, maybe put a charger on it just to make sure you are putting enough juice to it. Take the reeds off to make sure they are undamaged cause you shouldn't be getting backflow out the carb.