1992 Johnson 140 Looper install fine tuning questions. Rough idle/stalling after install.

[Smgbad]

Hi all. Just had a 92' Johnson 140HP Looper installed on my 86 Hurricane FD196. The gentleman that sold it to me installed it and did all of the throttle linkage connections while once it was moved over from his boat.

After letting the sealant we used dry for a week, I took it out on the water the other night and it was idling a bit low (around 650-700 rpm) in neutral. This low idle was slightly rough and it did miss occasionally, which would at times cause it to stall out. Also, I took it for some WOT runs and noticed about 50% of the time when I shifted it from WOT to Neutral the enigne would immediately stall.

Since the engine ran fine on his boat when we test drove it, I'm thinking the issue lies in either:
A: Old fuel (no idea how old the fuel in my tank is as I bought the boat with it about 2 months or so ago. It does have oil already mixed in, but that doesnt mean it's worth a damn. So I'm seeing what the best way to drain out that fuel would be (its in a big metal fuel tank in the hull). Thinking of then refilling it about halfway with non-ethanol and 50:1 oil mix and installing a new fuel water seperator filter.
B: The throttle connections are needing some adjustment. It shifts very smoothy except for the engine shutting off when going back to neutral. Anyone familiar on these models of what screw or adjustment I need to turn to raise the RPM slightly so maybe it will go into idle at neutral instead of stalling?

Lastly, does anyone know a simple way I can check to see if my rectifier is charging my 2 12V batteries? I'm still new to all this stuff and am learning via trial and error and asking questions. My first motor (that came on the boat) was a complete bust... SO really hoping I can get this one sorted out to where it's running smoothly...

If anyone is interested the compression reads 120-123psi across all 4 cyls.

Thanks in advance for any help you guys can offer!

 

[Smgbad]

Still trying to figure this out...

I searched out the issue on the forums a bit and am seeing that my symptoms could also be something called the "Shift Interrupter Switch". I've searched the parts manuals for my motor head to toe and can't seem to find where this part is located or the part number. Thinking my model may not have one. Anyone know?

Edit: Motor Model is a 1992 VJ140TLEN

 

[racerone]

Correct ---your motor V-4 models did not have that feature.

 

[Smgbad]

Correct ---your motor V-4 models did not have that feature.

Thx for confirming that, man. Would you recommend adjusting the idle speed screw then, or checking something else? I'm thinking the issue has to be with the way it was setup on my boat when switched over or the fuel I have might just be super old (no way of knowing)... I do know it smells like fuel and looks like blue koolaid... lol. Also, just for good measure I'm replacing the fuel/water seperator just in case.

 

[emoney]

Try running it on a portable fuel tank. Someone you know has to have one or you can pick one up at Walmart for $50.00. If the problem goes away, then it's a bad gas issue. If not, then I would find that manual and/or google "lync & sync" for those carbs. Idle mix screws can be set pretty easily and I think start at 1 1/4 turns out from lightly seated but I honestly don't remember. That manual is available as a download probably if worse comes to worse.

 

[Smgbad]

Try running it on a portable fuel tank. Someone you know has to have one or you can pick one up at Walmart for $50.00. If the problem goes away, then it's a bad gas issue. If not, then I would find that manual and/or google "lync & sync" for those carbs. Idle mix screws can be set pretty easily and I think start at 1 1/4 turns out from lightly seated but I honestly don't remember. That manual is available as a download probably if worse comes to worse.

I do have the service manual which the original owner gave me when I bought it, but some of the lingo they use is confusing to me. To follow it to a tee, I'll have to teach myself how to use a timing light.

In order to increase or decrease idle speed on my motor, is the easiest way just to simply turn the idle adjustment screw (the screw right above the WOT set screw), or is there WAY more to it that needs to be done than that? I dont wanna touch it til I know I'm not going to throw things futher outta whack.

 

[ecu1984]

go thru the link and sync steps

 

[ct1762@gmail.com]

you must disconnect throttle cable to do any idle speed adjustments. its the screw under the cigar-shaped plastic housing for the timer base linkage. then once idle set, re-install throttle cable on the throttle arm, then adjust the thumb wheel so it's slightly pulling the idle speed stop screw flush against the block, and pull any slack out. i will warn you: it will sneeze and cough if the link n synch isn't right. most important is making sure the cam roller isn't holding any throttle butterflys open (needs 5 thou clearance to make sure the running engine doesn't accidentally touch the roller, causing it to sneeze)

 

[Smgbad]

you must disconnect throttle cable to do any idle speed adjustments. its the screw under the cigar-shaped plastic housing for the timer base linkage. then once idle set, re-install throttle cable on the throttle arm, then adjust the thumb wheel so it's slightly pulling the idle speed stop screw flush against the block, and pull any slack out. i will warn you: it will sneeze and cough if the link n synch isn't right. most important is making sure the cam roller isn't holding any throttle butterflys open (needs 5 thou clearance to make sure the running engine doesn't accidentally touch the roller, causing it to sneeze)

Thx for the step by step. I'll be trying to tackle this at some point this week.

Just a couple questions to make sure I get this right... I've circled the screw I believe to be the idle adjustment screw in a pic of my engine I found online. Is that correct? Also, is the link n synch where I loosen the two nuts connecting the throttle arm to the carb linkage and make sure they seat and tighten them back down, and then adjust the cam arm so it just misses the cam roller by a hair (or 5 thou as you mentioned)? Does this have to be done with the engine running?

Lastly, any idea what the idle is supposed to be when out of gear? It's a sorta rough 750 right now.

 

[racerone]

I would be very very careful if you start making linkage adjustments !!----You said the motor ran fine on the sellers boat.

 

[Smgbad]

.

 

[Smgbad]

I would be very very careful if you start making linkage adjustments !!----You said the motor ran fine on the sellers boat.

Racerone: It was a bit rough to start on his boat due to really cold water, but once it got warmed up after a minute or two it ran pretty smooth. I've only had it out one time on my boat and it ran fine when in gear and did idle in neutral most of the time, but the idle was a bit choppy and around 750. The biggest issue was just it stalling out when I take it outta gear. Where would you start your investigation?

 

[racerone]

Temperature of the water has absolutely nothing to do with the starting of the motor !!-------Perhaps look into crankcase compression issues.------And all the other routine trouble shooting.

 

[Smgbad]

Compression reads 120 on all 4 cyls.

 

[racerone]

Crankcase compression is a different thing !

 

[ct1762@gmail.com]

it sounds like the guy who installed the throttle cable did not take the slack out or did something wrong somehow if it ran fine the 1st time then got itself out of wack the second time. you really should invest $25 or so for a used factory service manual! could be idle circuit is dirty! the manual will walk you through correct cable installation and literally everything else

 

[Smgbad]

it sounds like the guy who installed the throttle cable did not take the slack out or did something wrong somehow if it ran fine the 1st time then got itself out of wack the second time. you really should invest $25 or so for a used factory service manual! could be idle circuit is dirty! the manual will walk you through correct cable installation and literally everything else

I understand... And I have the original service manual. The problem was just trying to figure out what I should look at first. Maybe something I should check BEFORE going through the whole process of resynching. Only trying to avoid it as theres a few parts of the instructions I dont understand at all.

I am planning on following these procedures <iframe width="560" height="315" src="

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Seems fairly cut and dry, but I'm not sure how to use a timing light, but I did go ahead and get one coming along with a piston stop tool. Also, I dont have a test wheel, so not sure how to approach doing the idle screw since it says you cant do it on a hose or with a prop on. Also, the last part has the motor in gear... How do you work on that in the water with no access to the motor form inside the boat? Seems dangerous to be working on it in gear tied up to the boat ramp dock.

 

[Smgbad]

it sounds like the guy who installed the throttle cable did not take the slack out or did something wrong somehow if it ran fine the 1st time then got itself out of wack the second time. you really should invest $25 or so for a used factory service manual! could be idle circuit is dirty! the manual will walk you through correct cable installation and literally everything else

Also, what is the "idle circuit". I've been studying up on all the linkages, but didn't know there was a "circuit" involved.

 

[racerone]

If----" it ran fine on his boat " ----as you stated the only thing you would have to do is adjust your throttle and shift cable.----Hopefully this does not go to a 50 post drawn out saga.------There has to be to this story of it running fine when you handed over the cash.