HI GUY'S;
Just re-read some of my mags with articles on the KAWI650,and I am somewhat confused. In the Apr2002 issue of DirtWheels mag they had a shootout between the Prairie650,Polaris700,Grizz660,Bomb650,and a modified Hon Rub500. The article went on to describe some of the test's and so on, when they described the 300ft drags, the NON-modified bomb650 won against them all! I am not knocking the Bomb in any way. However you have some quads in this shootout that are much quicker in their stock form vs the Bomb650... so my question is what is wrong with the mods on these machines that caused them to be slower in a drag ( a 300ft drag at that ) The Pol700, Grizz660,and especially the Prairie650 are quicker in their stock form! Notice I did not say faster, the Bomb is faster top end due to its very tall gearing...but 300ft is not near top end!!! Makes one wonder... why mod at all.

ROB

 

I am currently investigating this issue, very slowly in my spare time.

It seems that all my mods have added low and mid rpm response at the expense of top speed, since I could go 64 at one time on a flat surface when it was stock, now I only go 63 on a good day on a flat surface (either with loose belt, and properly adjusted new belt).

Other people report this too. I feel that none of us have our main air jets right after we do an airbox mod. I am sure we are mostly getting our needles right, and our main jets right. We have not needed to mess with the pilot jets. We adjust our air screws. The main air jet is reponsible for the wide open, peak horsepower mixture of the carb. Why else would we all slow down when driving without the airbos lid. this is just my guess and I have been wrong before.

So, my best answer to your question here is: those modified quads were not really modified completey (or correctly), at least as far as acceleration and top speed are concerned.

 

Before you just hall off and bash me here, just try it.

Drop the main down one more size. Just try it, very easy and quick compare to other things.

 

Gaff may be right, from the posts I've seen from him he's no novice.

Hey Gaff, do you think Nyroc might have to richen up on the needle a notch after dropping the jet down?I think Nyroc said before that he was running one notch leaner than recommended on the needle as it was.

Oh, the drag thing, I don't remember whether that article said that they were dragging in high or low range.I'm supposing that with the oversize tires on that they would run low range for such a short drag(300').So it's probably a gearing difference.The results would probably be totally different on a longer run

In short, the Bomb may have taller gearing in high compared to the 650 ,and the 650 may have taller gearing in low.

 

Have you noticed much difference with the jet sizes changed! More low end or highend. Did you only change the jets because of the muffler mod or was it the air box mod and other things combined? what about trying the settings that dyno has teh needle I think I read it is in the 5th notch. Also, what would it do by moving it out a notch? Richer, leaner, etc...

 

I changed the jets last week because of the muffler mod. I got the dynojet a month ago along with filter and airbox mods. I have noticed more low and midrange power since I put one size larger jets in. Also, the transition from low throttle is perfect. It also pulls fast when I punch it.

I changed the jets due to the muffler mod.

Monte and King, the needle affects low throttle which is perfect on the 4th notch, and stumbles a bit on the 5th notch after the engine warms up.

Gaff, I think the my 650 and a few others around here are running lean on the full throttle, high rpm.

 

So you would still recomend going with the previous jet sizes for just the air filter and new intake I plan on getting as soon as it's avaliable 128f and 132r 4th notch then

 

The mud shootout in DW was a total travesty. they said that the riders chose, but in all actuality the mag chose. I know most of those guys and seen the quads they raced. I wouldnt take the findings to heart.

 

Nyroc, I was just thinking that if you upped the main like Gaff was saying,you might run a little richer everywhere, I'm pretty sure the main will also affect low speed, just not as much.

 

he said drop a size, but I know it was lean throughout the midrange and went up one size in the mains to fix it. Gaff was suggesting the reason we are all missing a little top speed is the jets are a little rich. I bet Gaff knows quads jetting better than I do, but I still think I have the needles and main fuel jets right. Everything works perfect, better than new, I just expected a little more top speed.

I am thinking the main air jet is a bit large, due to the restrictive filter and airbox. now that the restriction is reduced, a smaller air jet is needed. Whatcha think Gaff?