I recently purchased my first quad, a used 2001 DS650, and it appears that the last owner had tried to rejet. But it looks like they only stripped out the heads of the screws. I have replaced the screws and installed a jet kit. The settings are #3 from the top of the jet needle and a dj185 with 2 1/2 turns out. Over the last week I have tried many variations and still have not gotten rid of my problem. I am also using WhiteBrothers E-series and K&N stock replacement air filter without the foam cover from the stock filter.

The problem is once I get in the higher RPM's it sputters and sometimes pops. I also lose power.

Any suggestions?

[img]i/expressions/face-icon-small-confused.gif[/img]

 

Keep adjusting the air screw

 

I have a White brothers E-Series pipe & K&N filter in the stock air box on my 2001 DS650 so I have almost the exact same setup as you the differences would be possibly elevation & weather related items. I'd set the screw at 2.75 to 3.0 turns out from gently closed. I did the full test on mine and it ended up being 3.0 turns out was right in the middle of where it would sputter on the low and high end. I have the needle on the #3 and a 185 in my DS as well, however it is running a little too rich, but I haven't taken the time to fully re-jet since then since it runs rather well as it is.

As far as sputtering & popping, I wonder if your hitting the rev limiter? It is set very low at 7700 RPM and the engine will feel like it has a lot left to give when the limiter cuts in & makes the machine sputter & pop. (Now that I think of it, I think that is how I would describe the rev. limiter as well.)

The more I think about your comments the more it sounds like the stock rev limiter is causing all of that meaning this is all normal. To fix the problem, replace the stock CDI box with the Ron Wood Racing box.

FYI - I liked my 2001 DS650 so much I just bought another one! This time a 2003 DS650 Baja! You really can't go wrong with a DS650, congratulations & welcome to the family!

 

lol

I agree with Blackhawk. Your hitting your rev. limiter.

Opening the engine up to breathe and it is easy to get to the limiter.

Your jet may actually be a little high (trying to remember.)

By Stock Replacement K&N I assume you mean K&N in the air box?

So, other than that. You must be running pretty strong now?

 

The Ron woods CDI was on my wish list. But now it is a must have!!!

Thanks.

 

get the cdi you will be very happy[img]i/expressions/face-icon-small-smile.gif[/img] the wish list will get bigger

 

Exellent call blackhawk way to go[img]i/expressions/face-icon-small-wink.gif[/img]

 

The Ron Woods CDI is on its way[img]i/expressions/face-icon-small-smile.gif[/img]

I am using 92% octane would it be better to step up in octane?

Also I thought about getting a carb mount K&N filter. But I live in Washington and it is not recommended for wet riding conditions.

 

I took my brand new DS back to the dealer three times for that same problem. They said I had something in the jet then the next time they re jetted then said if I signed a waver for the mechanic to take my DS out to a ridding area to experience the problem first hand they would be better able to diagnose the problem. So I signed who knows what but I wanted this fixed. He had strapped on a tach and ran it. His conclusion was that I was hitting the rev limiter. Three days later my new Woods CDI was in and problem gone.

Maybe we all can get together for a class action suit against Bomb for knowingly selling defective designed CDI units and we will settle with them reimbursing the cost of the Woods CDI.

All in favor say I.[img]i/expressions/face-icon-small-smile.gif[/img]

 

Theres another quality shop [img]i/expressions/face-icon-small-wink.gif[/img]