Polaris 2 stroke problems

[2g00d4u]

This is the best of all places to ask I guess, I'm trying to fix my friends' polaris trail blazer 250 2 stroke, I can get it started with the pull start, for some reason its a total biotch to start with the electric starter, the pull start gets it in a few pulls, but it will idle fine for a bit, then start popping and idling lower and lower and then just die and it doesn't want to start back up, I have cleaned the hell out of the carb and put fresh gas in it and cleaned every wire connection I could find on it. I can get it to cruise around my yard a bit, but it will only go around the speed of the average lawn tractor, and it revvs up to normal, misfires a bit and drops, goes back up to normal rpms, then misfires a bit and drops, it just keeps doing this. Any suggestions? this video is of it idling itself out:

Polaris' are made so that you can't adjust the mixture or idle speed, its done to perfection at the factory, so that can't be the problem. Will try any ideas pitched. thanks guys.

 

[Zwiser]

probably lean.....

 

[2g00d4u]

how would I get more fuel into it though? there's no screws on the carb that I can see

 

[yzrider]

it sounds like its either not getting air or not getting fuel

 

[Braaaptor]

How does it run without the air filter in place? Polaris ATV's use an automotive-style paper filter that can get clogged with dust to the point that it chokes the engine. Sometimes, you'll never know until you replace the filter. Sand, especially, hides in there and you'll never get it clean.

If the engine still doesn't run right without the air filter in place, put on a new fuel filter and replace ALL the fuel line. Just trust me on this; we're getting all kinds of issues with swollen fuel lines at the shop. Still no go? Be sure the pilot jet is 100% clean inside the carb. Pulling the fuel bowl and spraying everything down with carb cleaner does not count as cleaning. Much of the time you have to be more thorough (as in, disassemble it all and clean individual parts).

If all this checks out and the fuel system is in good condition, I'd suspect an air leak somewhere. Pull out that leak tester and get to work. But it sounds like ur dealing with fuel problems to me.

 

[2g00d4u]

How does it run without the air filter in place? Polaris ATV's use an automotive-style paper filter that can get clogged with dust to the point that it chokes the engine. Sometimes, you'll never know until you replace the filter. Sand, especially, hides in there and you'll never get it clean.

If the engine still doesn't run right without the air filter in place, put on a new fuel filter and replace ALL the fuel line. Just trust me on this; we're getting all kinds of issues with swollen fuel lines at the shop. Still no go? Be sure the pilot jet is 100% clean inside the carb. Pulling the fuel bowl and spraying everything down with carb cleaner does not count as cleaning. Much of the time you have to be more thorough (as in, disassemble it all and clean individual parts).

If all this checks out and the fuel system is in good condition, I'd suspect an air leak somewhere. Pull out that leak tester and get to work. But it sounds like ur dealing with fuel problems to me.

Right now, I made the mixture as rich as possible and its running the best yet since the problem started, it will idle perfect, and I can ride it around, but it revs up, bogs, revs up, bogs, and keeps doing this, but won't die. I will try what you're suggesting right now, just an update on whats happened so far.

 

[244blackblastard]

I have a 400 scrambler I hate it but it's the girlfriends. These are some things i would suggest of problems i have ran into with mine. If it's still stock there should be an inline fuel filter by the fuel petcock that might be plugged I would pull the fuel line and make sure you get good flow to carb. check your spark plug and wire. check air filter or temporary pull it off and see if it runs like it should. This is a little more involved but you could of sheared off the flywheel key or flywheel nut is loose. It kind of makes me wonder that it starts by hand better than electric starter which would put less force on the flywheel or less force when trying to start. also as a warning in the future pull the engine dipstick and check for milky oil or also pull the rad cap when you start it and check for air bubbles...if you see anything like that you will have to rebuild the waterpump before it takes out the motor. The water pump bolts onto the end of the counter balancer and if the gasket or seals fail it starts leaking into the oil and takes out the bearings and seals in the motor. At least a $500 job not counting finding a place to repress a new bearing on counter shaft or getting a new counter balancer at $400.

 

[2g00d4u]

Its air cooled, so no water pumps or anything, I love the 400 scrambler personally, had one myself.

But back to business, I have done all of the fuel line cleaning everywhere possible, filter cleaning, carb cleaning, fresh gas, I took apart the carb and cleaned it, I ran it without the filter, I don't know what else to do. and it was running perfectly a few days ago, its a fuel delivery issue, its hard to start with electric start because the fuel flow is messed up. it needs the jolt from the pull start.