Engine problem

[rhtrudder]

have a mate with a 80 Rotax , at cruise , 5200, when he backs off the throttle a couple of hundred revs there is a slight miss but then settles down , does every time , l thought it was to high in the rev range to be carby balance, any ideas,

 

 

[Downunder]

Could be the change from full main jet to needle jet.....

 

Maybe check the rubber slide diaphragm for a pin hole? And needle clip setting.

 

 

[rhtrudder]

You might be on to something, sort of sounds like fuel, thanks

 

 

[skippydiesel]

Long shot but might as well throw in - as with all piston engines, any changes in throttle position should be gradual/smooth. Sharp changes can "upset" the engine as it adjusts to changes in air/fuel mixture.

 

 

[alf jessup]

Rhrudder,

 

What fuel does he run in it

 

91 or 95/98?

 

Alf

 

 

[rhtrudder]

Unsure , but I will find out , plane is a Europa, the one with the mono wheel and two wing stalks, gets along pretty good , thought the problem might have been a throttle cable hanging up but thinking about it the cables are pulling the butterflies closed when throttling back

 

 

[alf jessup]

Wal at Floods says only to use 91 octane on the 80 hp as that is what it will run best on.

 

Mind you a reputable brand though

 

BP, Shell, Caltex ect

 

 

[rhtrudder]

Thanks Alf , I’ll pass it on .