Rotax 277 on Hovercraft

by Ron Knight in General Tech Discussion 11 years ago

Hi Folks, newbie here to this site, name is Ron. I purchased a 1987 Scat Hovercraft with 277 pull start. We have been rejuvenating it, and now have motor starting, not running too bad. When we went to fly it, the craft seems way underpowered and will barely move across flat grassy areas at WOT. Same on water. After 25 minutes or so, with engine smelling hot, it just quits. Cleaned out carb (Bing 54) new premium gas @50-1 new fuel lines. There is gas in bowl, and floats seem to be floating ok and level. Went to check timing and found points had disappeared....someone replaced with CDI ??? Didn't know you could do that ! We are coming up short on ideas and would appreciate any you may have.

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Re: Rotax 277 on Hovercraft

by Dennis Richardson » 11 years ago

Dennis Richardson

1 153 174

Not enough information here to be sure but it sounds like it is over propped. At WOT you should be seeing 6000 to 6500 rpm. Another item to check would be restricted exhaust, rust scale, mouse nest or some other debri.
Dennis

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Re: Rotax 277 on Hovercraft

by Ron Knight » 11 years ago

Ron Knight

1 1 0

Thanks for the suggestions. We may have discovered the problem, or part of the problem. When I removed carb for the tenth time, I noticed a crack in the rubber elbow from the intake manifold to the carb. It was hidden under the clamp at one end. I replace it with a temp piece of rad hose, and it started up fine, and ran parked for 15 minutes at 1/2 throttle with no problem. I believe it was introducing too much air into the mix, causing lean running and high temp. The revs seem higher. We are going to try it out tomorrow on land, as the last attempt ended up with me and my friend taking an unexpected dip in the lake fully clothed. (Note to self: Do not move to the rear of craft to attempt restart when on water) :woohoo:

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