i have a 99 scrambler 400 4x4 and today when i was riding it acted like it wanted to die so it just went quite for a second then let off throttle for a secong and it ca, back to life, so the it did it a gain so i headed back. so when i went in for 10 min and came back out started it up to take to shed and for the first 30 feet it was fine, then it would barely creep along at all. so i had to push it the finally 10 feet. what is the problem? spark plug?

David

 

Sounds like a spark plug. Or something plugging your fuel system. Go the spark plug first, though. 90% of the time when a 400 doesn't seem to run right, that is all it is.

 

How often do you guys change the plugs??? Just wondering what to expect. Thanks.

-Josh

 

I ride with four other two stroke Polaris machines. Believe it or not, I've yet to see someone foul a sparkplug. I usually change my plug every four rides, but I don't think my buddies change theirs that frequently.

 

Mine did something a little similar last weekend. I thought it was the plug in mine at first, but I checked it and it was fine. It turns out what was happening was my gas tank was getting a vacuum in it and not letting gas go to the carb. I just had to keep unscrewing my gas cap every 5 or 10 minutes to relieve the pressure and it was fine. When I got back home I just drilled a tiny hole in the top of the gas cap, I think this will fix it.
I don't know if this is the cause of your probs, but you may want to try running with your gas cap loose to let it breathe a little and see if that's the problem.

 

Every four rides? That sounds like a lot. I have only changed the plug on my Xplorer twice I think, in 2200 miles!

When changing the plug, is there something special to do? Spacing?

 

how do you go about changing the plug?

 

Look under your gas tank at the top of the head. Take off the rubber boot with the wire running from it that you see. Back out the plug with the supplied spark plug wrench you got in your tool kit. Get a new BR8ES plug, gap it to .027", start it by hand to be sure it is threading right, then snug it down with the wrench. Do not overtighten it.

 

Still doing the same thing but now it just does the half die thing part of the time seems like after rode for around 3 minutes, replaced plug and tried gas cap deal...

help.

 

check air filter