My kids Outlaw 90 has always been a nightmare to start since we got it. Seems if it sits more than about a month without starting then I have to spray some starter fluid down the intake to get it going and then it will run on its own. After that its fine and will start no problem as long as its started every week. Once it sits for a month or more it won't start up.

Now its been sitting for about a year and it won't start, even after the starter fluid trick. I have drained the gas and refilled with fresh, pulled plug, cleaned/re-gapped and checked for spark, all good there. Pulled carb, twice. First time cleaned with brake clean and blew air thru, 2nd time I boiled it. It looks clean as a whistle and I could see no issues.

So what am I missing? It cranks great, has good spark, fresh gas, carb is cleaned, mixture screw was bottomed and then backed out 2.25 turns. It will fire on starter fluid but doesn't even pop or fire without it.

Any suggestions? I'm starting to think the carb is bad but at $400 for a new one I don't want to go that way just yet.

Thanks!

 

These little 2 and 4 strokes didn't have much vacuum pull to get fuel into the combustion chamber to begin with. If you're sure the carb is clean,jets are open,all orifices blown out,you can try to adjust the choke out a tad more to see if helps,plus on a different note check valve clearance as tight valves can affect starting and running. Worst case you can always do as many had to do on the 2 stokes and block off the air inlet when trying to start.This gives more of a fuel charge than air charge to get fuel into the engine. Not really fixes the problem,but better than shooting starting fluid into the cylinder and washing the oil from the rings and cylinder.

 

Thanks for the suggestions. The bike is a 4 stroke.

I contemplated valves being out but it will run for a few seconds on starter fluid and not at all without. I figured that if the valves were out or vacuum was low that it should atleast continue to run after getting it going with starter fluid.

I have tried putting my hand over the intake and there is a decent pull there as well as a decent push out of the exhaust.

 

Just as as a process of elimination I'd always check valve clearance because clearance is tight to begin with. .002 intake and exhaust. Rather than throw 400 bucks for a new carb,I'd rebuild one if you've exhausted everything you can do on the carb,plus checked for intake manifold cracks,fuel flow,etc. Very few places to get carb kits for these. You can either go here for individual oem parts or at least a new float needle for 20 bucks. Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse or you can go for a complete kit for about 40 bucks here.Polaris 50 90 Sportsman Outlaw carb rebuild kit 03-422

 

Thanks for the spec, I'll check the valves.

I did consider rebuilding the carb but I couldn't see anything wrong it any of the jets or needles. The seals/gaskets are o-rings any look ok as well.

 

Stopped by my local Polaris dealer to ask for advice and picked up a new spark plug while I was there. Mostly I bought the plug just so I actually spent some money and didn't mooch advice for free. I had a CR7 in it and they gave me a CR6 and also suggested checking the valves.

Came home, pulled the old plug to aid in turning the engine over to get TDC. Got it set to TDC and checked the valves, they were spot on. Bummer. Threw the new plug in and turned it over and VOOM! it fired right up. Must have had a bad plug which is weird because when I held it next to the head and cranked it over it had good spark. Either that or the quad REALLY didn't like that CR7 plug.

Anyway I set the mixture and idle and it seems to be running good now. I'll get one of the kids to take it for a spin tomorrow and see. My 2nd oldest is about big enough to ride it now so we'll see how she does with it. Her older sister didn't ride it much, a bit of a scaredy cat. Daughter #2 is a bit more daring so I'm guessing she'll be ripping around the yard in no time.

Thanks for the support! Next up I'll see if I can get my 2001 Sportsman running again, I replaced the cam almost 2 years ago and goofed something up and its been sitting ever since......

 

Simple things a lot of people overlook. This was one of the first bulletins we had on the 4 strokes was to go go a hotter plug on the 50 and 90. Same thing on the Hawkeye and Sawtooth when they came out. Came with a 7 series plug,had to drop to a 6 to keep from fouling. Glad you found the problem.