1979 Johnson 70hp over-revs

[Hoochie]

Gday,

I've got a 1979 Johnson 70hp here, haven't yet used it in the water.

The motor reaches very high rpm when the throttle plate is only just fractionally open. If I was to go to WOT it would surely damage the engine. This is being tested in a 44 gallon drum full of water to provide some back pressure.

I have little experience with outboards, is this normal?

There does not appear to be any air leaks surrounding the carbies, timing is fine, seems to blow a fair bit of smoke, but this is only running the engine for short periods.

Cheers,
Chris.

 

[cougar1985]

Re: 1979 Johnson 70hp over-revs

do you have a prop on ?just puttin my motors in gear in a barrel they become the worlds deadliest washing machine,lol.you cannot run a motor properly in a barrel, you need a test tank to go into higher revs and preferably a test wheel.the prop is what gives you a load,without it your asking for trouble.

 

[Hoochie]

Re: 1979 Johnson 70hp over-revs

No worries, time to put her on the water then.

 

[tashasdaddy]

Re: 1979 Johnson 70hp over-revs

check link n sinc.