johnson 140 83 idleling rough

[tblshur]

hi everyone my j140tlcte have to push key in 3 or 4 times to keep it running at cold start runs real good on top end been rebuilt about year and 1/2 any way the guy that rebuilt it turned the little thumb wheel to adj. idle it worked fine some time later it started idling about 1200 rpms and oll me turned the thumb wheel didnt lower idle could that have changed the throttle pickup timing? also i have different advice on which plugs to use currently using ul77v flat tip and i notice some fuel on the water no visible leaks maybe front of carb

 

[Bosunsmate]

Re: johnson 140 83 idleling rough

Yes, it will make things not retard as much (when he adjusted it up) so its interesting you rethumbing it didnt fix that. It shouldnt of suddenly increased to 1200 rpm as well.
Have you checked that the timing linkage is retreating properly and isnt getting its wires entangled in anything on the opposite motor side?

 

[emdsapmgr]

Re: johnson 140 83 idleling rough

It's normal to have to push the key in a few times till the engine warms up and runs on it's own. Usually, turning the screw on the spark advance lever is enough to reduce the idle timing (and the idle rpm's.) You set the idle when the boat is floating in the lake and is in forward gear. You can't set it on the trailer. 650-700 rpm's is the target. Possible the sync and link is off slightly, or the carb is staying open somewhat. The recommended plug is that UL77V, the same one the crossflow V6 uses. Stick with that plug. Sometimes the carbs will drip a little fuel out the bottom of the airbox. Make sure the drain line is connected between the bottom of that airbox and the hose barb at the bottom of the crankcase. (should have a gasket between the airbox halves, too.)

 

[glenn property of pam]

Re: johnson 140 83 idleling rough

does the timing lever move freely?

 

[tblshur]

Re: johnson 140 83 idleling rough

thank you guys so much for your quick responce sorry i didnt get back sooner im at the lake now camping no inernet thanks to mcdonalds y;fy i can answer the 1200 rpms was some time back that is when i moved the adjustment after that idid find the wires sticking the advance lever.my memory not much that fixed the 1200 rpm i was trying to give history im not very good at telling things i panicked .the adjustment i made was the black plastic nut on the linkage cable where it comes in the motor.any way i think ifound some of the problem, i changed some little rubber lines going to powerhead the ones i got may have been fuzz larger one had come off i put back on it idle much better and gas dont leak like it did.the plugs are kinda wet and have some carbon plugs are 2 wks old i cleaned them it ran very good, now the latest thing yesterday fished several spots started to go to fuel up throttled up it would not plane out pulled back to idle then throttled up it ran great. i dont have a gasket between air box halfs,the marine e dia,dont look like mine cant find part # for mine. thanks for all your help better go now they have sweep under my feet 2x may be a day or two for me come the 20mi here

 

[Bosunsmate]

Re: johnson 140 83 idleling rough

It doesnt sound like you need to do much more to it as it is now running great pretty much the whole time. Finding an intermittent fault like you had when it didnt want to power up will mostly take a lot of head scratching to find and make for not the best holiday.
If you want to do anything i suggest running seafoam through it to decarbon the engine and doing a lynch and sync.
No rush on either of these.

 

[Bosunsmate]

Re: johnson 140 83 idleling rough

I make the part number for the gasket to be sierra 18-0985 about $4

 

[tblshur]

Re: johnson 140 83 idleling rough

thanks Bosunsmate for the part # that gasket shows to be a 4 bolt, mine is 8 or 10 bolt im home now and boat is at lake cant remember exactly .yesterday before i left iwas changing fishing spots at 5000 rpms all of a sudden it dropped back to 3 or 4000 rpms for a few seconds then back to running the great the rest of time.am i wrong to think that the stator is only for charging the battery the scematic ive looked at kinda looks like that but i remember reading some threads about the tack working off the stator.im going to check all my ground connections any suggestions what to check be much appreicated. thanks again for all your help.keep your line wet.haha:laugh:

 

[Bosunsmate]

Re: johnson 140 83 idleling rough

stator charges battery through rectifier. stator also has leads which provide the charge to the powerpack which eventually gets to your sparkplugs.
tach gets a line to it off near the rectifier, its normally grey you should see it connected there somewhere near the rectifier. So long as your battery is charging fine and your revs a showing i would leave all that gear as is.
It sounds like one of your coils could be starting to fail or a sparkplug. See if any of your coils have any big cracks.

Lines wet and tight for snapper here

 

[tblshur]

Re: johnson 140 83 idleling rough

Bosunsmate again you have cleared up the way things work, thanks.i think im will borrow a timming light ,a spark tester and compression gage and start checking a little more. Lords will ill go back to lake next week and post anything i find or more questions if you guys dont mind.thanks again.:watermelon: