Hey all you DS experts, I'm quoting this from another forum and I would like to help this kid out let me know what you all think the problem is. It sounds like some serious carb issues to me but I don't know.

"ok me and my bud both have ds 650. he has an 02 standard edition. and this thing has problems, the main and biggest on is it miss fires or back fires horribly sometimes. i mean it does it so bad and constanly he cant ride it. it blows flames and crap out his exhaust wich makes me think its firing at the wrong time? any ideas? i think it might be the cdi. and..it burns Anti-freeze. i dont no if it has a bad head gasket or what. the main problem is the miss firing. it has the stock cdi. another think i noticed oil spewing out of the crank or stator breather (i forgot what one it was) that goes up under your seat into the in-take hoses. Heres a pic of the hose on my quad so you no what one..It is spiling out under the seat!!! so yea what the heck lol please help"

Thanks.

 

Head gasket is toast, that one I am sure of.... Also may need at a min rings, maybe even a piston.....

 

Maybe his flywheel moved a little, mine did the backfire thing by having it out of time.

 

def a new head gasket (the antifreeze deal)
I would pull head and check valves (for damage and clearance) as well as the piston...that much blow by (oil coming out breather) is a problem and means there is pressure going in the crank case from the cylinder! I used to get small amounts of this with my 03 but if its a really large amount I would pull the head to check ,before you find pieces of piston in the valvetrain!

 

I had a similar problem with mine a while ago. It would back fire and loose alot of power. The dealer found that the choke was stuck open and fouled out the plugs. Something to look at.

 

ya if its backfiring out the exhaust it is def. too rich (the unburned fuel is igniting in the exhaust cuasing the backfire). If the intake pops (backfire through the carb/airbox) it is generally too lean.

Sounds like there are multiple problems here!

 

well when you have anti freeze burn that should move to problem number one. like the others guys said head gasket. the early ds's all had oil that came out of the breather tube, like the dragon said it can be rings. so where to start, since the head gasket is in need of replacement it's a great time to replace a piston which will have new rings. after that you can start checking carb and exhaust for proper jetting and exhaust leaks, once those areas are in good working order things will operate proper.