1974 9.9 question s

[Starboardlean]

Great compression. Spark that puts lead in your pencil. New coils, points, condenser, and rebuilt carb. Starts super easy, trolls and slow rides great. Try to go fast and she does it for a few seconds, loads up and slows down. Does not shut off, just quits " pulling". So I search the forum. She passes the drop cylinder test. Then I find this thread:

http://forums.iboats.com/forum/engi...948-9-9-evinrude-won-t-go-over-3000-rpm/page4

So I break carb back down and sure enough it is a # 54. So I ordered an OMC correct part 319016 and it is a #51, but the advice in thread is a #34. Sea trials are tomorrow. Of course the barrel test was great. Your thoughts on the discrepancy between the advice in other thread vs OEM??

 

[flyingscott]

I highly doubt you have a jetting issue because the motor has run since 1974 on that jet. I would look at the fuel pump. The motor in the post is a 1992 model NOT the same as yours.

 

[Starboardlean]

Pumping bulb had no effect.

 

[flyingscott]

How long have you had the motor? Is this a new problem? Is the float set correctly? Do you have a good quality tank? Is the vent open on it?

 

[Starboardlean]

2 months. Non running when bought. Float bowl is set per instructions. Good tanks, other motors( 6hp and 85hp )run fine with them. Will know tomorrow for sure. Some defiantly either tried to "make a 15" or inadvertently put the wrong jet.

 

[flyingscott]

are you sure that is not a 15 hp carb

 

[Starboardlean]

are you sure that is not a 15 hp carb

Not sure on carb...never even seen a 15.Sea trials went outstanding.

 

[tomhath]

She passes the drop cylinder test.

Passing at idle only means you have spark at idle. It sounds like you're dropping a cylinder at higher RPMs. That can happen if the plug wires are getting old.; the insulation starts to crack and break down - at higher RPMs the higher voltage starts to arc through and you lose spark. Try replacing the wires.