I just got a 2000 DS650. When i went to pick it up it ran strong, but when i got it home it started acting up. It will start right up with no problems. It runs strong for about ten seconds then it sounds like it's loading up. It will backfire and pop and will not let me go anywhere. I have replaced the plugs a few times with the correct plugs (I do not know what the gap needs to be though). I have drained the gas tank and cleaned the carb. It is getting fuel. I have just about ruled out fuel. The backfire is so rythmatic that i think it's electrical. Both plugs are getting spark but I'm ruling that out yet. The only other thing it air. We have plugged and unpluged vacum hoses and the air filter and it doesn't really change the way it runs one way or another. I am new to this but i have some motor knowledge. Please let me know what you think. I'll try anything. Thanks for your help.

 

I had a similar problem once and it turned out the rubber boot between the carburetor and the engine intake had a big crack.
It started fine but when I accelerated to much air was allowed into the engine causing the same type of symptoms.
Hope this helps.

 

Was it the rubber piece in the Carb, or the rubber hose between the carb and the engine?

 

diddo on the carburator flange that goes to the manifold....also check to make sure the diaphram on the top of the carb is seated good, and the bowl seal is seated good. if you got ANY carb cleaner on that diaphram it will swell and not seat good. same with the bowl gasket/seal.
I might be way off, these are just things i discovered with mine....

If the flange does have a hole/tear look at Home Depot before buying a stock one. They should have one to fit in the plumbing section....and they are only like 4.99 compaired to 15 or 20.

Good Luck

 

I would take the boot between the carb and intake on the motor off and go to the auto parts store and get some radiartor hose. If that doesnt stop it open the top of the carb and check the diaphram in the top for any cuts or tears. after that maybe check the CDI

 

I do not think the diaphram is damaged. I will check tonight though. I have not checked the hose between the carb and the engine. If i would check the CDI, Where would i find that and what would i check for?

 

Alot of guys go with after market ones and I bet someone has a good stoker laying around. Check on the garage post

 

Where on the bike is it located? How would i test to see if it's bad?

 

The CDI is located just under the tank on the left side. It is a little plastic box about 2X3 inches bolted to the frame.
Usually the only way to test it is to try another one on your bike and see if that makes a difference.

 

Try cracking your gas cap when it does it. . . doubtful but, chould be your tank vent.

Pull your seat off and try holding the fuses. . . again, doubtful but, the fuse holders sometimes become loose.

Check your plug wires. The wires would sometimes come loose from the plugs. . . only a spring in the cap holding them on the plug.

hmmmm