Primer bulb problems

[Oldboatguy8911]

I have a 76 merc 115 inline 6.. I recently sea foamed the engine and it freed up my carbs and cleaned out the lines and everything for fuel.. Now that I have the motor accelerating properly it seems now its not getting enough gas to run at WOT for more than 5 minutes without the primer bulb collapsing .. Sometimes when I prime the bulb it doesn't even seem like it is priming gas but that it is filled with air?? I have secured my lines and now I'm at a loss...

 

[guyjg]

... to run at WOT for more than 5 minutes without the primer bulb collapsing...

Check your fuel tank vent...if you open the fill cap and the bulb doesn't collapse then the vent if not working.

 

[fastjeff]

Time to replace the fuel pump diaphragm(s) and check valves.

Jeff

 

[Oldboatguy8911]

Ok so I tighten all my hoses, checked the vent it is working.. Now I think that I have a miss? I will plane out at WOT and I hear it missing .. How do I check for that? Also it seems like it tops out an holds at WOT but revs down some and I slow down to slower speed I know that this motor has more power than what it is topping out at what are some things I can adjust this?

 

[guyjg]

I will plane out at WOT and I hear it missing .. How do I check for that?

While someone else id driving I would put a timing light on each plug wire at 3500 RPM to see which one is not firing.

 

[Oldboatguy8911]

And if I don't have a rpm gauge??well that's a dumb question I should get the digital timing light. An that will identify my miss?

 

[guyjg]

I only said 3500 RPM since it is not always necessary to be at WOT to diagnose a misfire. Besides, if it happens, I'd rather fall overboard at 3500 vs. 5500.

 

[Oldboatguy8911]

Very true .. But what about the rev down issue? I will feel it just rev down from WOT and just cruise .. Why does it do this?