Mystery to me

[SDuster11]

Heres the info: 70 horse I3 Merc. clamped on the back of a 10' GW Invader should move perty good and has but when i first mocked it up i had trouble with it. That being it would idle fine but once in gear it would idle up a little bit and then would bog after about half throttle to the point of dying. Took it to a local guy he said i had to big of prop on it and (at the time it was a 21P) he put a 14P on and also he said the primer bulb was crap so he put another one on. After that it ran like a spotted ass ape! However bout 2 months after the same problem crept up again (thinking it was dirty carbs I cleaned em) took it to the river SAME THING we could play with it for a while with intermintint squeezing of the primer bulb and then try it and 1 in 10 tries she'd jump out of the hole the other 9 it's fall on its A$$

Also the primer bulb never gets hard. Aren't they supposed to pressure up? I'm gonna go and get another bulb tomorrow and hope that maybe might think of something that I havent here. Lemme know what you'll think Thanks

[Jay R.]

first steps would be the primer bulb and making sure all fuel lines are tight

[pyro]

Primer bulb should not get hard. If it goes flat, there's a fuel restriction behind it.

Kind of sounds like my motor. The more hours I put on it, the worse it gets. I have to keep pitching down or I can't get on plane.

[WILDCAT2.5]

I can be wrong but it sounds like your fuel pump diaphrams need replacement for fuel is passing into the block via the fuel pump,check them as I said I can be wrong.

Markus

[yanny_haulinbass]

on the right track. My 2.4 was acting similar to your 70hp when my fuel diaphram ruptured. Fuel was entering the crankcase and flooding out the engine really bad. If I was able to get it up on plane it would make power and use a ton of fuel. The primer ball would go flat and the motor would stall.

[SDuster11]

Aight i replace the fuel hose from the primer bulb to the motor and a new bulb and put it in a trashcan full of water and put it in gear and tried it. Seemed perty good.
Next we took it to the river and tried it SAME thing. I was unable to break it over at first but after about 5-7 min. of trying i was able to break it over. once onplane i kept it onplane for about 10 min. making some passes at higher speeds. In that time it used aproximately 2+ gallons. I just pulled off the fuel pump and the check valve seems to be good I can suck on the outlet and blow on the inlet and it seems well, can't do the vice aversa. On the fuel pump there are four inlet/outlets one from the tank, one to the screen/carb, and then one the last to are just joined to each other by a hose. What does the last two do? Thanks

[The Big Al]

I can be wrong but it sounds like your fuel pump diaphrams need replacement for fuel is passing into the block via the fuel pump,check them as I said I can be wrong.

Markus

I agree with this! very good chance!

[SDuster11]

how do i know if the diaphram is good or not? The one on right now is still sealed up to the block, so all i see is one side and it appears to be in good condition w\o any tears or major holes. What's your take on this? thanks