I am fairly new to the 4 wheeled world but not to dirt. I traded a KTM625 for a 2001 DS650. At 46 yrs I am getting to old to hit the ground and bounce back up and at 6'3" and 275 the DS is the only sport bike that fits (still love the power and speed). On the second ride I experenced some problems that I related to the carb so I took it to the shop I had gotten the KTM from and had them clean the carb and change the jet to the K&N recommendation of a 175. After reinstalling the carb I rode the DS for a while but was somewhat disapointed with the performance. My neighbor was out running me drag racing on his 400Z. Since it was used I figured I would take it to my dealer and have it looked over. They told me that the diaphram had a hole and I was running dangerously lean. They had spent about 3 hours on the jetting and had it better though still lean according to them with a 200 jet (the biggest jet that they had ever put into a stock motor). I rode the bike at the dealer for about 5-10 minutes and it was like a whole new machine though it did stumble once. The stumble was attributed to the old outer filter (so I purchased a new one while there) or the in line fuel filter (replaced with one piece fuel line when back home). Enough backround. Recently I went riding for the day in about 95 degree heat and after about an hour of feilds and trails we went out on the gravel roads for about an hour long loop. The bike started laoding up and I had to keep it running high in 3rd gear where I would normally cruse in 4th or even 5th. It was popping out the exhaust and had no power if I let it get low in a gear. At one point we turned to go up a hill and I had to stop and rev it up 3-4 times to get up the hill slipping the clutch in 1st gear. I pulled the plugs and the KTM dealer said that they didn't look that bad and he recommended that I raise the clip 1 notch. I called the DS dealer and was told not to do that but to try adjusting the air/fuel mixture and I fthat didn't work go to a 180 jet. I looked in the manual and do not find anything labeled or instructions on adjusting the mixture. I am confused by the different advice and was hoping that someone here may be able to help on who's advice to follow. I have been going to the KTM/Arctic Cat dealer since he is about 2 mailes from home and the Can-Am dealer is about 1-1/2 hours away in each directon. The guys at the Can-Am dealer seem to be knowledgeable and most are drag racers. I have been reading the Extreme Garage and this forum for sometime and this seems to be the place to get the type of information that I need. Please Help and Thanks in advance!

PS I envy those of you with the big sand boxes to play in but hope to make a trip to one in the future.

 

Popping is symptom of lean, and thottle position determines which jet circuit is being used. Its not alot of fun being held hostage to the dealership for issues such as jetting.
Your best bet is to learn about jetting, and be able to trouble shoot the symptoms on your own. Its not difficult. Read up on jetting, like this article And youll be able to do your own jetting.
The article has the symptoms of lean and rich, and also tells how to figure out which circuit is the one that has a problem. It also explains how to set the mixture screw.
You did a good job of explaining the issues, now youll need to figure out at which position the throttle is, to know which circuit is lean.
Welcome to the forums

 

Just glanced at the article and am prining it now but looks very informative. Thanks for the quick reply and I think the guys at the Extreme Garage forum were right and this is the place to get your questions answered. Thanks Again!

 

If you were having trouble crusing at 4th and 5th, but ran good with open throttle in 3rd then it is the clip position like you were told. That will need to be adjuswted, and then you will be able to lower you jet also........

 

http://forums.atvconnection.com/mess...%20carb%20mods


With the RW cdi you have alot of ignition advance.

My recommendations to start:

Pilot screw out 3 turns.
Needle in the 4th position from top down.
Main jet 180

Check float per the above specs.

 

My ? to you is that you had mentioned that the diaphram was torn that will cause a huge mess for the carb if the bladder was torn...But you said they messed with the jetting and never mentioned if they actaully got a new bladder/diaphram...Do you currently have any mods on it also so that way we can get an idea on where your jetting should be at?...How do your spark plugs look color wise? If you can do it yourself save your money instead of a dealer doing it for you...with a new ds I would inspect it over this part is off topic but I would check the oil and make sure you drain the oil tank and the pan, repack the rear bearings,brakes,a good antifreeze for the ds is engine ice and you can get it from rockymountainatv.com,adjust the valves,and a problem that alot of people have had on the ds there is a ventline under the plastics that attaches to the gas tank itself and if that is kinked it causes the bike to sputter so you may want to check that also. On the early model ds's they had problems with their fans/thermostats so what I did was I tied my fan into a manual switch so I can turn it on myself.

 

Thanks for the answers so far. In reply to bombrider04
Yes, the dealer did replace the bladder/diaphram.
Only mods are:
K & N Filter in Stock Box
FMF Power Core 4 slip on
Ron Woods CDI
17 Tooth Front Sprocket installed before last ride by the dealer
Plugs seem dark to me but KTM dealer said they weren't bad. They were white on the tips where the electrode comes out of the ceramic for about 1/16" and then black.
Thanks for the additional advice and I will be doing some of the things this fall to semi winterize it. Did have the dealer do the oil change whie they had it and they used Klotz full synthetic.

 

Yea I ma sure you know the white tip means you are running lean which you mentioned before and you said it was darker so them you are fine...I would def check the vent line comming from the gas tank that thing is a pain take off the cover on the gas tank and you will see a fitting and a vent hose that goes from the fitting to the rear of the quad I would recommend cuttin it shorter or taking it off for good...I am running a 190 main with no airbox lid,full exhaust,and a K&N filter with a prefilter just to give you an idea. try jetting yourself and start with a higher jet then 175 and work your way down...If you need advice on the carb even though to me you said the plug isn't white anymore it sounds like you have gotten the mixture pretty good...If you need help on carbs omr is very knowledgable along with the others so give them a shout...My guess would be if the plugs seem to be alright then try messing with the ventline and go from there and make sure the bladder is seated correctly even if it is new...If your carb is fine and the line then there are a few other things that have come to my head so let us know how you make out.

 

I was reading over your mods again and it said you had a ron woods cdi do you guys with experience with the woods cdi had any troubles with it on a stock engine with stock valves and such?