Can't keep it running.......

[Jdude1]

76 25hp johnson 25RL76E ignition kit ,carburator kit ,installed. engine runs fine in the garage in the garbage can , as soon as I put the cover back on it wants to die and I can't get any power I take the cover off and it runs fine again any ideas..?

 

[Jdude1]

Second question : when the primer bulb is primed does it have to remain hard to prime while the engine runs?

 

[boobie]

Put the motor on a boat, take it to the lake and run it. Then get back to us.

 

[Jdude1]

I took it to the lake it kills under throttle like it is starving for air I'm about ready to drill a hole in the cowling

 

[jbuote]

I'm no pro, but it sounds like an exhaust leak.
Runs well with cowling off, but put cowling on and it wants to die..
IF it's that, then probably have to pull power head and change gaskets..

Gurus can explain better if I'm even close, which I could be completely wrong, but that'd be what I'd be looking/searching forum posts for.

To your second question... I don't think it has to stay firm, but definitely shouldn't "Deflate" and look sucked in.
That'd be poor venting on the gas tank..

Relative newbie $0.02

 

[Bosunsmate]

^i agree with all Jbuote says but also check the aitintake on the cowl isnt blocked, its normally under the handhhold on the upper rear

 

[Jdude1]

There is no venting of any kind under the cowling it is one solid piece. I will do a compression check and a leak down test soon, I do not suspect an exhaust leak. But I may be missing something ,frustrated after time and work spent on this thing, thanks for the help.

 

[oldboat1]

That primer bulb -- is it collapsing while running? Could indicate an issue with tank venting or pickup.

 

[Bosunsmate]

There is no venting of any kind under the cowling it is one solid piece. I will do a compression check and a leak down test soon, I do not suspect an exhaust leak. But I may be missing something ,frustrated after time and work spent on this thing, thanks for the help.

Im not familiar with that outboard but every motor needs a vent to get oxygen in for the motor intake so i assume youve checked whereever its meant to be coming in that thats ok

 

[OptsyEagle]

If it runs fine without the cover and stalls or looses power with it on, you have an exhaust leak. There is no other failure that is caused by putting a cover on the motor.

Yes, the primer bulb looses a little hardness when running. That is normal.

 

[OptsyEagle]

Fire it up and with it running, spray some WD-40 along all the gasket edges and see if you see the WD-40 bubbling up in one position or another. Do the exhaust cover on the side of the powerhead and where the powerhead is attached to the mid-section.

 

[jbuote]

I will do a compression check and a leak down test soon,

Compression test is good, but the leak down test isn't going to tell you much on a 2 stroke.
IF I'm not mistaken, the leak down is mostly useful on a 4 stroke for checking if low compression is rings, valves, or head gasket.., but is almost useless on a 2 stroke.

Would love to know if I'm wrong though.

 

[Jdude1]

Took some soap and water and sprayed all the gaskets with it running no bubbles of any kind present I have some leak detector at work I will try to verify again but nada on the bubbles , I did however use 85% of a can of seafoam to 5 gal of fuel could that be an issue?

 

[Jdude1]

The only smoke I get is pure white from the can I run the motor in

 

[oldboat1]

If the powerhead is mounted right above the barrel, it's sucking in the exhaust. Run a fan when testing to clear out the exhaust, and feed some air.

 

[Jdude1]

Did the compression test and it was fine , I'm going to take the boat out and try it again , if it happens out at the lake I'm going to blow it up and sink the whole thing !!! :embarassed::blue::blue::blue::blue::embarassed:

 

[oldboat1]

Pictures! Will want pics from safely on shore.