[cwkoch]

Hey- I'm having issues with my back-up sled that I just can't get solved. It's a 98 Indy 500. It likes to foul plugs, and sometimes it will bog down and not rev over about 5000RPM. I did jet down one size, but hasn't seemed to help much. My buddy rode it in the UP all last weekend and it ran fine. Then, my girlfriend was riding it yesterday and it was fine until she had it floored running some drifts. Bogged down and wouldn't move. Put new plugs in, and it didn't help. Plugs were wet with fuel when I pulled them out. I've heard I may need a new CDI??? Has anyone had these problems?? Any other suggestions?? Should I try to go even smaller with the main jets?? I'm so fed up with this thing I may have to resort to bringing it in to the dealer!! :banghead:

 

[williewonka]

do a compression check, sounds like a burndown.
snow ingestion will do that.

 

[can-amsledder]

First things first :welcome:

You have to think your way though this checking one thing at a time. Don’t get discouraged yet. Like willie said a compression check is a good starting point. I don’t know the exact PSI for you sled but anything over 120 should be good.

As for the main jets, what size is stock ( might say on a sticker under the hood ) and what size is in there now. Anything more then two sizes down would be a lot.

How was the sled last year? If it ran good last year then it must be jetted about right.

Check the color of the spark, should be blue-ish not orange. Orange might mean a weak spark.

And lastly, you have come to the right place to get help. Give it a couple more hours and you will have lots of ideas of thing to look for.

:HCS_rules:

:mother_nature:

 

[CHUB_CHUB]

i had the same problems with the same sled last year, havent had it out this year

 

[montecarlo33]

I had the same problem with my families 99' Indy Classic 500. It would bog down and run like a dog, foulin out plugs. This fall we tore down the carbs and found that the needle on the chaincase side had dropped. It would run fine, when you put fresh plugs in, but then the next time it wouldnt even start. It sounds like you should have someone who knows about carbs take a look at it. I dont know that much about it, but me and a buddy fixed mine.. Hope this helps :beerchug:

 

[cwkoch]

I had the same problem with my families 99' Indy Classic 500. It would bog down and run like a dog, foulin out plugs. This fall we tore down the carbs and found that the needle on the chaincase side had dropped. It would run fine, when you put fresh plugs in, but then the next time it wouldnt even start. It sounds like you should have someone who knows about carbs take a look at it. I dont know that much about it, but me and a buddy fixed mine.. Hope this helps :beerchug:[/b]

Are you talking about the needle and seat, or the needle on the carb slide?? I replaced the needles and seats both last year. They had been leaking and would flood the motor when you parked it if you didn't turn off the fuel valve. The needles on the carb slides are all the way down, so leaning it out some. I can't remember what size the jets are, but what's in there is either stock, or one size down. I know a little about carbs....but this thing is just being a pain. it will run fine, then bog down. Sometimes it will clean out and come back on it's own, but sometimes not. I guess I'll just have to pull the carbs and see if anything is messed up in there. I didn't pull them at all yet this year, but had them off last year to clean them.

Maybe I should just replace the sled with an EFI sled like my new one!!!! Then I wouldn't have any more carb problems anyways.....

 

[cwkoch]

OK- compression is good. Spark is strong and blue. Mains should be 350, and I have 340's in there. Should I change pilots?? What about Needles??

Also- I think this sled came with champion plugs, and I switched to NGK BR8ES long ago.... should I go back to those stock champions that were in there?? Does anyone know what they are?? (can't find manual).

Thanks.

 

[can-amsledder]

BR8ES are a bit hot if anything, most everyone runs BR9ES which are colder. And the NGKs should be fine.
What I really need to know is did this sled run good before with this car setup. If it did I would be looking outside the carb.

 

[pockets]

BR8ES or RN3C are the plugs to run.

 

[gen2]

Make sure your choke cables both a free. Also make sure they are set loose enough to have a little slop in the flipper before it starts to pull on them.
The bogging down sounds like your dropping a cylnder. Might want to put new spark plug clamps on. they are only a few bucks each.

 

[need2snow]

It sounds like time to check all the real basic stuff.
Broken intake skirt on piston?
Fuel pump diaphram cracked?
Fuel pick up line in tank broken or cracked?
Broken clutch spring, or unhooked?
If it has good spark, check timing?
Junk in airbox or exhaust? you won't believe what can be found in them!
Pressure test cooling system?
Base gaskets and crank seals?
Good luck, been there before too, actually all of the above...

 

[need2snow]

...The needles on the carb slides are all the way down, so leaning it out some.
... I know a little about carbs....[/b]

Just re-read your post. A freind had his needle dropped all the way down (96 Indy 500) and blew a piston trail riding at part throttle. Maybe try going back to stock settings, middle clip position? He was trying to get better gas mileage.

 

[jcm700]

One of the guys I ride with had a similar problem. While it was bogging, he would open the hood a few inches and it would clear right up and take off.
If you try that and it clears up, I'll ask him what he did. I know he found the problem.
I'll ask him anyway.