Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (carb)

[SweetD]

Appreciate some insight to my recurring stalling issue with my 2005 Johnson 90hp 2 stroke carbed motor. Specifically, the motor likes to stall while in neutral / idle, or very low RPM in forward gear (like in a no-wake situation). Two situations and questions:

1) I recently discovered that the fuel primer bulb had cracks / pinhole leaks in it. It was a cheap Taiwanese model. I replaced it with an OEM "Made in USA" bulb. Checked all the fuel line fittings and lines (all were brand new in 2007, correct fuel line for ethanol, etc.).

Could the cracks in the fuel primer bulb have affected the idling of the motor, perhaps causing it to stall due to air infiltration at low idle? I can push the center / spring-loaded section of the cap up with my fingers, but it's quite resistant.

2) My fuel tank is also new as of 2007. Sits above deck under the forward center console seat, so I have full access to it. It has a vented fuel cap. The center of the cap is spring-loaded, and I assume it's supposed to open and close to allow venting, although I'm not sure how it actually functions. Here is a picture of the cap / tank:

Could it be possible that the cap is not functioning properly in its venting, and that is somehow restricting the fuel and causing the motor to stall at low RPM?

I should also mention that once the motor gets up and goes, it runs very strong. If the stalling symptoms are present, the motor often bogs down before suddenly "kicking in" and taking off.

Thanks for any opinions / expertise / trouble shooting tips.

Dave

 

[levi_tsk]

Re: Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (c

dude seeing how those new vents they mandated are untested and unproven id have to un hook it and go with a standard vent hose and vent JMHO
was it running fine before you replaced the tank??

check to see if its sucking the primer bulb flat at idle if it is that vent is suspect

 

[SweetD]

Re: Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (c

Thanks Levi,

It doesn't suck the bulb flat at all. But is does seem like there was very little fuel in the "old" bulb when idling. Now, I have to test the system in the water with the new bulb (boat going in this week for the season). I ran it on the hose this past weekend and it seemed to idle very well in the driveway.

I got the motor after I replaced the tank, so I have never run the motor on a tank other than the one pictured above. I also have not run the motor on a portable tank yet.

So I'm willing to test it anyway I can - I'm just asking if the things I describe above (cracked primer bulb, bad vent cap) could be contributors.

I've never heard that the "new vents they mandated are untested and unproven"? Can anyone chime in on that?

Thanks,

Dave

 

[SweetD]

Re: Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (c

Man this forum is active - less than 24 hours since I posted this and already on the fourth page back!

Any other opinions / advice?

Thanks,

Dave

 

[Fed]

Re: Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (c

Specifically, the motor likes to stall while in neutral / idle, or very low RPM in forward gear (like in a no-wake situation).

I should also mention that once the motor gets up and goes, it runs very strong.

You have a carby problem not a fuel supply problem.

 

[levi_tsk]

Re: Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (c

sorry had a busy day today....

sweetd - change the bulb out if not that then it could be the fuel pump or dirty carbs if it doesnt fix it with the bulb try some omc engine tune in the port on the primer solinoid (it looks sorta like a tire valve stem and its red with valve stem cap on it) follow the dirrections on the can if that doent work feds right and id tear down the carbs and put new kits in it but not before i tried the engine tune

starting in january 2011 the EPA in their infinite wisdom(lol) decided that fuel tank vents on watercraft should not vent into the open air (like they have for the past century or so) so they came up with this retarded "gadget" for a lack of a better word, which is spring loaded and vents pressure when it gets too high or too low but isnt open to the air full time. ive yet to use one myself or see one in person but if its anything like those new fill nozzles on the handy cans like they have now, ill keep my normal vent as those new nozzles are retarded (takes 10 mins to pour 1 gallon of gas out of one) not to mention fragile

 

[SweetD]

Re: Could these factors be affecting my stalling issue? 2005 Johnson 90hp 2 stroke (c

Wanted to just follow up on this thread for someone else's possible benefit. Thanks Levi for the advice. I changed out the primer bulb which was a cheap POS Chinese model and it was cracked, and installed a new OEM / OMC Made In USA bulb. Put the boat in the water and it was running much better.

For about 20 minutes, until I had a significant fuel leak. Could not tell from where the fuel was coming, so had to yank the boat and bring it to the mechanic. After waiting a week over Memerial Day weekend timeframe to have it diagnosed, I got lucky. It was a cracked fuel line at the VST brass nipple at the top of the motor. Fixed and no more leaks. Motor is running great and is NO LONGER STALLING at low RPM / idle speed.

Hopefully that's it for the summer!

Dave