I have a 2002 Sportsman 90 that runs awesome..........ONCE it stays running. I am having a hard time starting the quad if it sits after a few hours. I will drain the battery to nothing and then have to kick start it from there. What happens is the bike will start for 2 seconds then die........then wont start for another couple minutes worth of electric and kick starting. this will go for several short running starts. then once i get it running, it runs great. I can start and stop it all i want............till it cools off. this is getting frustrating for my kids and I.

I have changed the spark plug, cleaned the carb, adjusted the air screw, adjusted the idle screw, put new gas in. i even leave the gas manual shut off valve in the ON position to make sure there is fuel in the carb. I have replaced the needle/seat assembly in the carb. seems like i have done almost everything. to me, it seems like the engine is starving for fuel.

I did read some people complaining about the stock electric choke on these bikes. and that there is a manual choke kit out there as a replacement for this atv. does this sound like a good idea to try? if so, where do i get these manual choke kits and are they easy to install.

any and all help would be greatly appreciated.

BB

 

Try blocking the air intake tube on the air box with your thumb then crank it. Should crank a lot easier if the carb and everything else is ok. These little ones are hard to get the fuel running into the carb. The conversion choke kits helped a little,but I've still had to block the air intake on these too,especially when cold or have been sitting up awhile!! This procedure just allows the engine to pull in more fuel to crank. Even received an "in house" bulletin from Polaris on doing this. Plus a Polaris manual choke kit costs more than an after market carb on Ebay! OPT

 

So it's a simple as blocking the intake upon start up? I have an 02 and can usually get it to start right up cold. My boy will take it around the yard a few laps and then it starts to lose power and stalls. We then have to wait an hour or so for it start back up. And the same thing continues to happen.

I've read coil, carb, fuel, choke...any other recommendations other than blocking the intake? Is the reason for stalling out just too much air going in? I've read in another post where it was as simple as adding a new battery.

I've been reading alot of your posts OPT and you seem to know your stuff! I appreciate your time and feedback.

 

Welcome to the forum! What blocking the intake tube does is to allow engine vacuum to draw in more fuel than air for quicker starts than just grind the starter down or kick start these little atvs forever. Your problem could be more top end related since once it gets hot it dies . Rings could be loosing seal against cylinder. Do a compression check cold and when it dies and see if there is a great difference. The manual says 115 psi is minimum compression with a cold engine. Plus check the tank air vent for any kinks(vapor locking could cause it to gulp air slowing down fuel supply to carb. Plus any restrictions or kinks in the fuel line to the carb and that fuel is flowing good. Plus have had a few fuel valves that would not allow good flow of fuel. You can kick start these little ones with a dead battery. If all checks out,then the other problem that the little ones had were stators shorting out,getting weak, from dirt and water entering through the plastic cover. Replaced quite a few of these over the years. Hope this helps. OPT

 

Thanks for the response. I'll try to get into it this weekend. I do have a slight oil drip from down around the oil pump and dripping on to the bottom frame and exhaust.
I have kept an eye on the tank to see how much i'm losing and it's not much at all. Could the issue possibly lie in there? Or is that just another fix I need to make eventually but currently has no effect on my current peformance issue?

 

Anything that could cause an air leak,carb gasket, air in oil injection line,leaking pump,etc should be looked at as it could cause a lean running condition. Could cause engine to overheat and piston/ring damage could happen. OPT

 

OPT, thanks for the input. The quad sat for 24 hours. I hit the starter, it didnt start. I plugged 80%ish of the air intake pipe and within a second or two, the bike fired up. I let a small amount more of air in to keep the bike running no too lean. I will let it sit for 2 days now and see if that helps! But I am confident, this is the fix I have been looking for. Great help (as usual) OPT.

Kaz Man, i did a compression check on sportsman 90 and it was 112 PSI. just so you a reference as to what an 02 sportsman compression is at. And let me tell you, its a pain in the butt to get a compression tester in there. the spark plug cant be any more dead center with the steering shaft and frame. Best wishes with your fix.

 

Agreed that it sucks taking a compression reading on the 50s and 90s Don't think they could have had the frame and steering post any closer to center of plug! That's where short adapters or swivel compressions hoses help! Hope the tube block off solves the hard starting for you.Thanks for giving info to other posters,hopefully both of you can figure out your problems. OPT

 

OPT, once again, great advice. I let the quad sit for a couple days (kids hated that part). and the bike fired right up by blocking (choking) the air intake tube. all the struggles and carb tear downs and adjustments and dead batteries from trying to start and kick starts................and now it is over. for now!!!! it is still a 2 stroke. so plugs will foul, carb will need tweaking/cleaning and all the good stuff. but for now..........life is great again.

can you recommend a good 2 stroke oil to use for the 90?

 

On these little machines any TCW3 rated injector oil is ok. Penzoil, Quick Silver,even Wally World 2 stroke injector oil. Not necessary to buy the expensive synthetic unless you just want to. Good luck. OPT