Down a cylinder DASA 1200. Any guesses?

[johnmarchetta34]

I was riding when my ski became down on power big time. It felt just like a fowled a plug so I put fresh plugs in it and it did the exact same thing. I noticed that it was idling very high and sounded very odd. I checked spark and compression in both holes and they were both fine. I then pulled the plugs and saw that the front plug was not burnt at all but the back one was. I tried running on just 1 plug in both the front and back. The back hole sounded perfectly normal. However, the front hole idled very high and sounded much worse. I assume this issue is fuel/ carb related in just the front hole? Any guesses on what this might be before I tare it apart? Its a DASA 1200 with OEM ignition & MSD enhancer, BUM carbs.

 

[bkspeedwerks]

Check the pulse fittings and make sure they are tight and did not fall out. Have seen them fall out of dasa cases.

 

[Harbor]

I’ll add, make sure the throttle blades in both carbs are opening and closing when operating the throttle lever.

My coupler between the carbs came loose on the slave carb so only the carb with the throttle cable was operating

 

[ScottS]

Remove your flame arrestors, start the engine and look down the throat of the carbs as you rev it. As Harbor said, it will let you see if both carbs are opening, but it will also show you if both carbs are getting fuel, or if the fuel is atomizing or just dribbling out. Most importantly, it will let you see if you are getting blow back from a broken reed valve. This is something I check first after looking at the plug whenever my ski starts running funky as it's so easy and tells you so much.