90 Johnson 140 VRO Stalls at Low RPM

Hello everyone, I need your assistance since i'm a newbie here.<br /><br />The outboard starts fine and runs great at high speed, the motor stalls at low speed(about 5 to 8 knots) when i'm trolling out of the marina. I cannot give you further details about the rpm since my tach is not working properly. i'm planning on changing the tach over the weekend.)<br /><br />i have further issues about not reaching max rpm but i'll take that to further discussion since i don't have exact rpm readout.<br /><br />can someone give me some guidelines in troubleshooting?<br /><br />Thanks.

Re: 90 Johnson 140 VRO Stalls at Low RPM

Do you have a compression tester?<br />If so, what's your compression readings?

Re: 90 Johnson 140 VRO Stalls at Low RPM

When was the last time you replaced the thermostats? Those motors do not idle well unless up to operating temp.

Re: 90 Johnson 140 VRO Stalls at Low RPM

Thanks guys.<br />About Compression Test. I do not own one. Previous owner told me about a month ago that he performed the compression test and they were at about 130 on all 4 cylinder. I have no way of verifying that unless i take it into the shop, which i'm sort of considering. I bumped a yacht yesterday bcuz my motor stalled while trying to park the boat for live-bait. embarrasing but he was nice enough to let it go since there were no damage. engine runs well above 5knots but in between 1 to 5knots while in gear, it continuously stalls. very agitating.<br /><br />as for the thermostat, since under my posession(1 month), the answer is no. unless my thermostat guage is not working, the motor runs very cool all the time. even at continuous WOT.<br /><br />thanks for your feedback.

Re: 90 Johnson 140 VRO Stalls at Low RPM

any suggestions?<br />thanks.

Re: 90 Johnson 140 VRO Stalls at Low RPM

I had the same problem, Ran fine at speed, stalled a lot near idle.<br /><br />My situation may be completely different from yours.<br /><br />One check you might try is, with the motor running on the garden hose at home, unplug a spark plug wire and notice the engine change.<br /><br />On my motor (3 Cylinder) unplugging #1 would kill the mototr, unplugging #2 or #3 would only drop the RPM a little. It turned out I had bad scoring on #2 annd #3. That's why a compression test will tell you a lot. You can eliminate that possibility if the comession tests turn out OK.<br /><br />A manual is a must. It can tell you the correct operating temprature, which would also be good to know.<br /><br />What tests have you preformed?

Re: 90 Johnson 140 VRO Stalls at Low RPM

i got a word back from my mechanic today that the compression seems to be ok. they ran 145-150 across. i'll be taking a look at the carbs tomorrow. hope this will give me some ideas.<br /><br />thanks and if you have any further suggestions or comments, it would be greatly appreciated it.

Re: 90 Johnson 140 VRO Stalls at Low RPM

You could adjust the throttle cable a round or 2 to increase the rpms at Idle that's how i fixed both my older 115 Johnson Crossflow once it got a little low on compression and i noticed my Evinrude 140 VRO was the same but had 142 psi on all cylinders so i just turned up the idle a couple rounds on the cable to fix the problem you may just have a stretched throttle cable. Good Luck

Re: 90 Johnson 140 VRO Stalls at Low RPM

what service manual do you recommend?<br />i have a seloc manual and not really satisfied about it.<br /><br />as for the throttle cable, how do i check to see if it's stretched? if so, do i need to replace them?<br /><br />Thanks.