I posted last week on this forum about my 650 after I put in the Dynojet kit, DiamondG Snorkle and TwinAir filter. Went on a long 121 mile ride and now the quad seems to be slightly hesitating at first stab of the throttle.

I first noticed it as I was trying to do high range wheelies, which were easily capable after the air filter, snorkle and jet kit mods and before I put 121 miles on it. I've tried it over and over and I notice that the quad hesitates for about 1/2 second as soon as you stab the throttle. It then comes right out of the hole hard, it's just that first initial stab of the throttle that it isn't responsive.

It's actually not too noticable, but I know it wasn't doing this before (immediately after I put the jet kit in). I have the needle's at the 5th notch and running 128 front and 132 rear jets as per DynoJet specs.

We did have a run in with bad 87 octane gas when we rode last week. A grizzly and a sportsman 500 both were backfiring and running like crap. Wouldn't go over 1/2 to 2/3 throttle, and would just stutter and backfire. Dumped dry gas into both machines and ran carb cleaner through them for a while. They quads cleared up and then ran well. It happened again to the Sportsman again, after he got gas at the same place again. I gassed up there too, but I put 93 octane in after seeing the problems they were having with the 87 octane. I haven't had any of the problems they had. The quad ran great.

Think it could be the gas causing my problem?

Hoping for an easy fix...

 

It could be but did you check your air filter is it still clean just a geuss[img]i/expressions/face-icon-small-confused.gif[/img]

 

The filter was brand new but got caked with dirt & dust from the ride (very dusty). I took it out, cleaned it with twin air filter cleaner. I let it dry overnight and put it back in w/out oil to give it a try yesterday. It was doing the same thing, just a slight hesitation on first stab. I reoiled the filter and will be putting it in tonight. Doubt it's gonna make any difference though.

 

We all run the needle jet on the 4th notch instead of the 5th like dyno said. I have the same set up but with a UNI filter and I am running the 4th notch.

 

I read somewhere that people with your exact setup are using the forth notch instead of the 5th. I don't see how this would effect your situation though?

 

Whoops...my bad...I am running at 4th notch. Sorry.

What controls idle and low-end revving, needles?

 

I actually thoght the manual says to use at least 91 octane in it. I use 93, just a few cents more and I luckily haven't had any probs yet.

 

Hey parker,I had the similar problem w/my Wolverine after a REALLY dusty ride..try using compressed air to blow out your jets..I had a very small peice of dirt stuck in the tip..finaly had to use a needle and poke it out

 

I also have my needle at the 4th notch. I bet you got some water in your carbs. Even though you use 93 octane I thought you would still get some fuel from the 87 octane tank and it is mixed with a high octane to give it the 93 octane rating.

 

idle to 1/4 throttle is controlled by the pilot jets. Maybe there is small piece of junk stuck in your pilot jet.