Help with Old DOO

[outcold]

90 or 91 formula mach1 w/617 twin, starts and idles for a second then seems to go to about half throttle and stays until shut off. there seems to be something hanging up somewhere but it quits before you can figure out what it is. I'm a CAT guy so the rotary valve and everything around it is new to me, one cable goes to something between the carbs right above the valve not sure what this is but it was moving smoothly where moved with a finger.
Other than that I will be checking the carbs again since I think the slides are sitting too high any suggestions or ideas would be great. I got this sled for fifty bucks so spending a few to get it fixed is not a big deal. THANKS

[slideways]

I had the exact same problem with a 670 Rotax this fall. I put one of the slides in backwards when I cleaned the carbs. There are two slots on the slides, but only one of them is long enough to rest on the alignment tab and let the slide go down all the way.

The result you get is one carb almost wide open and the other at idle. Simply take the airbox off and see if one is open farther than the other.

At least you can say you weren't the last guy to have the carb apart!!!!;)

[outcold]

that was it thanks, was going to check the carbs out anyway.


Why would they make this a possibility? my Cats won't go back together unless the slides are in correctly. Oh well it runs great now and the chaincase is needing attention.

Thanks again