[Chevytech49]

I have a 94 Polaris 300 2 Cycle that wont start. I have been having problems with it since I bought it. It doesn't make sense to me as it will start sometimes and then other times it wont start at all. If you wait awhile (day or so) and try it again it usually starts. I have noticed that when it does start, you have to fan the throttle since it bogs down when you first touch the throttle. I tried starting it last night to see if it would run today for my hunting trip and couldn't get it running right. I tried starting it for about an hour and it finally started. When it started it bogged down. I finally got it to clear up and revved it a bit to clean the cylinder out. I let it idle to make sure it would continue to run and it died. I checked the plug and it was barely wet (looked like a little film of oil on the porcelain part). I have tried to start with choke on and off and it doesnt seem to make a difference. I do smell gas when I crank on it eventually. Checked the spark and it has good spark. Changed the plug and still nothing. I did notice that if I let it sit for like an hour or so and go out and try to start it it will start on the initial hit of the start button and immediately die. After that it wont start at all again. I'm trying to find out why or what to look for so I don't tear into this searching for something that may be simple. Are there any common problems with these atv's? Thanks for your help

 

[roadiestar]

check for air leaks

 

[Xploder]

notorius for cracked intake boot, also sounds like carb is dirty, running lean, prob pilot jet clogged, my 96 300 was a bitch to start at times if it sat for over a day

 

[Russ C]

chech compression, needs at least 100psi

 

[Chevytech49]

Checked for vacuum leaks and I didn't see anything. The only thing I seen was the clutch cover inlet duct hose dry rotted and separated.

 

[Chevytech49]

Intake boot as from the carb to the cylinder? Or from the carb to the air cleaner housing? It would make perfect sense that this would be an air issue but I don't see anything else.

 

[Chevytech49]

I forgot to mention. When it does start it starts up on the first crank almost everytime.

 

[Xploder]

then does it run lean?, will it run good if you choke it?

 

[Chevytech49]

I'm not sure. It always starts (when it starts) without choking it but I haven't put the choke on after it's running. It seems to run fine when it does run. Just on the initial start up the throttle is "boggy" and you have to fan the throttle for a bit to get it cleared up.

 

[mrfxit]

I too am working on a xplorer 300 and have similar carb issues. when i got it it would not start at all. i adjusted the air bleed screw to the factory 1.5 turns and then found my throttle cable and choke cable were completely out of adjustment. well to make a long story short i now have a engine that only starts on either then runs and idles pretty good. i found through some reading in the tech manual that in order for the engine to start cold the idle enrichment circuit has to be open to allow extra fuel into the engine so it will start. i would bet you need to pull the brass choke adapter off from your carb and blow some carb cleaner through the passage or adjust the choke pull.

 

[Xploder]

Call me fordtech50........is what i am, how about you?

 

[Xploder]

Let's all agree...It wouldnt hurt to remove the carb and teardown and give a good cleaning!!

 

[Chevytech49]

Fordtech50?

 

[Chevytech49]

What do you mean by fordtech50 how about you?

 

[Xploder]

Means the same as chevytech49, I assume your a chevy tech by trade and are 49 years old

 

[roadiestar]

Check the reed valves make sure they are closing.

 

[getuaload]

your problem is bad crank seals, these engines do not have reedd valves. they us the piston and crank case to create vacum to pull in from the intake/carb. when the seals go out & they do it will suck air in too much air and basically its like removing reeds from a reed engine and see if it will run.
cheap fix, its most likely the one on the clutch side. need to remove the primary clutch and you will see the seal right there.. replace it and your good to go