'87 Johnson 50hp VRO(deleted) Idle speed issues

[IamHim]

Hello, I have a 87 Johnson 50 that won't run at idle. If I get it to idle, it always dies out in less than a minute. If I use the warm up lever, it starts at a higher rpm, with occasional surges, and if I lower it to idle I can keep it running by choking the carbs with my hand. I have fuel spitting out of my upper and lower idle air bleed orifices. Cleaned and rebuilt carbs twice, 2nd time I noticed if I cover the jets with my thumb and blow carb cleaner into the idle orifice with the carb inverted, carb cleaner leaks out where the emulsion tube enters the top of the carb. The manual says that is not good and to seal it, but I don't think that would cause all the issues I'm having. Timing is good, new fuel tank/line, new plugs, new cables, new coils, stator checks out okay, new fuel pump, carb float level seems okay. Anyone have any thoughts?

 

[racerone]

Trouble shooting starts with a compression test.----Post your numbers.----Possibly check the flywheel key.

 

[IamHim]

Trouble shooting starts with a compression test.----Post your numbers.----Possibly check the flywheel key.

My bad. I meant to put it. 150 and 151 +/- 1

 

[IamHim]

My bad. I meant to put it. 150 and 151 +/- 1

And the flywheel key is correct within a half a degree

 

[racerone]

Are you running with the conventional fuel pump or with oil blocked off to the VRO ?----Does it still die out if you operate the manual pump ?-----Does it die out if you run with another tank and hose ?-----I always say it,----" it should be fairly easy to determine where the issues is "

 

[IamHim]

Are you running with the conventional fuel pump or with oil blocked off to the VRO ?----Does it still die out if you operate the manual pump ?-----Does it die out if you run with another tank and hose ?-----I always say it,----" it should be fairly easy to determine where the issues is "

 

[IamHim]

The VRO pump has been completely removed, I've got the fuel pump for the non VRO model on it.

It dies out if you're operating the manual pump.

I've tested it with a tank and hose that came right out of a boat with a 89 50hp VRO. No change.

 

[racerone]

I would say that it is running lean on low speed mixture circuit.----Need to look into that.-----Thermostat in place and working properly ?----Where exactly did you apply sealer ?

 

[IamHim]

I would say that it is running lean on low speed mixture circuit.----Need to look into that.-----Thermostat in place and working properly ?----Where exactly did you apply sealer ?

I haven't applied the sealant yet. The skinny tube that goes from the bowl to the top of the carb, right where it enters the top, is where you're supposed to apply it. The thermostat has tested good recently, would that have any affect on it able to run at higher rpm?

 

[racerone]

if engine runs cold it may not idle properly.

 

[IamHim]

if engine runs cold it may not idle properly.

Gotcha. Well it opens and closes when its supposed to.

 

[juno pierrat]

did you remove core plug on top of card, 2 or 3 little holes under it could be clogged

 

[IamHim]

did you remove core plug on top of card, 2 or 3 little holes under it could be

Yes I did

 

[juno pierrat]

if when motor starts to die, can you raise the rpm's with warm up lever and keep motor running. if yes, would think it maybe a weak fuel pump. even through its new. also might try raising idle rpm's, half to full turn on idle screw. as for spiting fuel, ive got a 87' 48spl and a 50 like yours, think that's a common thing. ive got a manual, were does it talk about sealant in carb , interesting

 

[racerone]

There are no idle mixture screws shown for a carburetor on 87 models.-----If it dies out gradually while idling it may be running lean.----Issues with reed valves ?----Are both carburetors throttle plates CLOSED at idle ?? bottom crankcase seal ??------Some trouble shooting required here.

 

[juno pierrat]

raise rpm's at idle with idle adjustment screw, i think it advances timing, i agree no mixture adjustments,