73 model 9.9 evinrude

[cat783]

i need some help guys. this motor runs fine and then once you are going almost full throttle it makes a thump noise. like it cuts out then goes right back to running fine. its like hitting a stump but there is nothing there. i have taken it to several shops and noone can find anything wrong with it. anyone have any ideas?

 

[iwombat]

Re: 73 model 9.9 evinrude

Could be a faulty kill switch, or kill switch wire. Although the "thump" part doesn't quite match that.

Is it more like an ignition backfire, or something drive related?

 

[F_R]

Re: 73 model 9.9 evinrude

You took it to several shops and nobody knows what's wrong? Where do you live, the Great Dismal Swamp? Any outboard mechanic worth his salt knows that's the clutch dog and forward gear. It's coming out of gear, rotating one half turn and slamming back into gear. Here in FL, the customer says it a little different: Feels like he hit a gator.

BTW, the '73 is 9.5hp, 9.9hp came out in '74 They are different.

 

[cat783]

Re: 73 model 9.9 evinrude

you are right my 9.5 is a 73. well i have heard that quite a few times about the clutch dog. i asked the last guy to check that and he said it was fine. the swamp part isnt far off. no big shops will work on it. they say its too old. the only mechanics that will touch it are unprofessional ones i guess you could say

 

[iwombat]

Re: 73 model 9.9 evinrude

seaway marine (seaway.com) had a clutch dog in stock when I inquired a few months ago. Turned out I didn't need one, but figured I'd at least see if they were still available.