Help friends quad on crack!!!!

[Dune Surfer]

engine speeds up then slows down after jetting. I know two members experiencing this problem. Any expert advice?
It is strange, the quad runs ok but the reves keep going up then back down until it almost dies or does die.

[ewalker302]

Probably just karma catching up with you
for buying that polaris. Ha

[Pappy]

if it was a car id suggest an air leak in the intake tract:confused:

[Dune Surfer]

Originally posted by ewalker302
Probably just karma catching up with you
for buying that polaris. Ha

Ha ha ha It's not my predator. It is a 400ex:eek2:

[Bad Habit]

What year 400? Didn't the 99s have a problem with the intake boot (between carb and head) cracking or coming apart? This would let air in and, dare I say it, Pappy would be correct?:eek:

[ewalker302]

OK I see now

I thought it meant help friends------ my quads on crack.

Now I get it.

I still think you should have held out for the new 450.

Let us know what happens the first time you race one up the dunes.


:bandit:

[Diedrich]

yeah i've think i heard of the 99's having the problem with the air boot..tell him to check that out man

[Pappy]

i know that sometimes the throttle cable will get kinked into a weird position and cause weird things:ermm:

[Dune Surfer]

I gave him a new air boot and that didn't solve it. I think it's an air leak too, but he has checked the carb, intake, I don't get it

[zoom400ex]

make sure you screwed in the main jet tightly, because if it falls out you will be running extremely rich..........i had this same problem with my 400 i could go all the way till about 1/2-3/4 throttle and it would bog down and almost die out.

[Big - D Racing]

that was my bike I would take off the carb dissamble clean it all out real good, then reassemble. Hopefully that would fix the problem.

[Dune Surfer]

bump

[Atreyu]

I would remove the carb and use some gum cutter on it, and check the boot. ;)

[BigThumper33]

to ensure you don't have a air leak. Take some carb cleaner and spray it all over the carb, boot, and air box boot. If this makes it run funny thats your problem. If not, I would take the carb part and clean it. Might have something gummed up.

[4TraxRider]

If you took the chocke out and replaced it with a cap, the cap might have fallen off. Happened to my friend. Just a thought.

[Glamis400ex]

What a pal you are Dune Surfer...;)

I'll try the carb cleaner trick..never thought of that.

I'll look for the cap on the choke as well.

I hope to get it all apart and clean and check everything.

Stay tuned...

Glamis

[Dune Surfer]

If you do the carb cleaner trick, do one thing at a time to help narrow it down. Good luck:) One way or another we will find a way:D

[Glamis400ex]

oh yah, not worried, but still need to find out what it is before dune season is upon us...:eek:

Glamis

[CowsBitePeople]

Originally posted by Atreyu
I would remove the carb and use some gum cutter on it, and check the boot. ;)

Cleanness waaaaaatt:macho

[hondafox440]

Try a leak down test. Remove the pipe and plug the exhuast manifold, then plug the intake and pump the engine up with 8PSI of air. Spray the motor down with Simple Green. If there is a leak, the Simple Green will bubble up around it. The motor should hold 8PSI for about 6-8 minutes without losing any.

[pnut420]

This sounds like a carb problem for sure. Ive seen a couple times where the carb gets stuff down in the needles, etc.... happened to my edelbrock carb on my truck, the tuck would idle at 500 RPM then jump to like 1200, wouldnt run for crap, so I crossed the spark plug wires (which is no good in this case) and as soon as I started the motor it backfired (which is what I wanted to do) and then all this dirt flew out of the carb, I switched it back and it ran like a champ, an old school mechanic showed me that little trick, I did it twice and it worked great.

[Glamis400ex]

Thanks to all who contributed...one of these suggestions HAS to do the trick...

Glamis

[Atreyu]

No Prob man...


LOL waaaaat