"DK" wrote in message
...
Eisboch wrote:
"Mike Slater" wrote in message
news:knfZl.742458$yE1.158636@attbi_s21...
I was cruising along in my 24ft pontoon boat when I got a real surprise.
Somebody please tell me how and why I could be running wide open
throttle at my normal 5500 rpm and then suddenly the boat took off like
a bat out of hell running at 8000 rpms and 25mph??? I never touched the
throttle. It has never run that fast ever. After about 2 minutes it
went back down to 5500 and never did 8000 again. Its a 60hp mercury
Bigfoot outboard. It has never done this before and I don't even know
how it could rev that high and go 25mph. Normal is 5500 and 17mph.
What happened??

Mike


Is it a two stroke? I've often noticed on 2 stroke weed wackers or
chain saws that just as you are about to run out of fuel they speed up.
I think they start running lean due to air in the fuel line.
Is it possible you had a temporary air leak in a line and a similar thing
is happening?

Eisboch

For two minutes? I can't believe 8000 rpms didn't blow it up!

My boat runs comfortably at 10,000 rpm. g

--Mike

mgg wrote:
"DK" wrote in message
...
Eisboch wrote:
"Mike Slater" wrote in message
news:knfZl.742458$yE1.158636@attbi_s21...
I was cruising along in my 24ft pontoon boat when I got a real surprise.
Somebody please tell me how and why I could be running wide open
throttle at my normal 5500 rpm and then suddenly the boat took off like
a bat out of hell running at 8000 rpms and 25mph??? I never touched the
throttle. It has never run that fast ever. After about 2 minutes it
went back down to 5500 and never did 8000 again. Its a 60hp mercury
Bigfoot outboard. It has never done this before and I don't even know
how it could rev that high and go 25mph. Normal is 5500 and 17mph.
What happened??

Mike

Is it a two stroke? I've often noticed on 2 stroke weed wackers or
chain saws that just as you are about to run out of fuel they speed up.
I think they start running lean due to air in the fuel line.
Is it possible you had a temporary air leak in a line and a similar thing
is happening?

Eisboch
For two minutes? I can't believe 8000 rpms didn't blow it up!

My boat runs comfortably at 10,000 rpm. g

--Mike



Your pontoon with a 60hp Merc Bigfoot? Nice!