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J140TLCUA Recirculation issue

P

Pmadewell

New member
Hello,

I'm serving my recirculation valves on my Johnson 140, and am having issues cleaning the valves going into the cylinders. I have a service manual and am using a syringe with alcohol, however I can't pass fluid either direction, it's like the valves are completely blocked off. The one way valves in the manifold are fine and functioning just as they should. Does anyone have any info on this or know how to unplug these, other than splitting the block and going in through the cylinder... Btw, servicing them because I believe they are affecting my idle.

Thanks!

Paul
 
That '87 Johnson of yours has only leaf valves. If these are the valves you are talking about, then remove the carbs, remove all bolts that mount the intake onto the crankcase cover and take it out. You will need a new intake gasket after you clean all old gaskets off and reinstall the reed and intake back.
 
Well this is the model number straight off the block and it certainly has the brass check valves in the recirculation system. One in each intake manifold, which are connected to the brass nipples on each cylinder.

I rebuilt this motor about 4 months ago, and it ran flawlessly for the first 10hrs or so. But it has slowly developed a slightly irregular idle, drifts between 800-1000rpm. I have checked every darn seal on this motor trying to find a possible air leak somewhere, but i can't find anything.

I rechecked compression to make sure nothing was happening there, and all cylinders are right around 145psi.

I have been through the carbs THREE TIME NOW, and there is nothing in them, they are spotless. Ran wire through the idle/intermediate pickup tubes and all that fun stuff...

So the recirculation system was the last thing i could think to look at. Since I can't get any fluid to flow through the valves on the cyliders, then obviously the puddled fuel in the intake is staying there and not making back to the cylinders. And from what i understand, the recirculated fuel on these motors has been factored into the carburetion at idle and itermediate. So that would mean the motor is running a bit lean at idle? Also, this would explain why i have no issues at higher RPM as the recirculation system is pretty much null and void because there is no fuel puddling at that time? I'm no spe******t, just thinking outloud.

Second question, if these valves are indeed clogged, what is clogging them and what caused it to happen? When i rebuilt this motor, everything was cleaned to perfection - trust me, i was there... So something has happened between then and now, and it only took about 15 or so hours of operation for it to happen.

Thank you for the reply and would greatly appreciate any other ideas or thoughts on this issue.

Paul
 
Unscrew and replace em...$35 ea. It still wont idle good as 1987-89 had crappy carbs and intake(tea cup).Put a late model intake and carbs on it and it will run 50% better. Its a small bore motor so smooth idle wasn't included in design.
 
Thank you for your response, but like I said, the one-way valves that you can unscrew are fine. It's the valves that go into the cylinders that are plugged up. I can not pass fluid either direction through them. Wondering if I can just take off the heads and clean them out that way? How do they get clogged, carbon buildup?

Thanks, Paul
 
Shouldn't get clogged as on intake side of piston, you can heat he are around them with a torch lamp or heat gun and slowly twist em out...
 
That's what i think is strange since like you say they are on the intake side. I really don't understand what could be blocking them? The manual clearly states that you should be able to "easily" pass isopropyl alcohol both directions through them. I can stick a small nail through them and don't feel anthing, nor does any debis or gunk come back on the nail, it is completely clean. Is there any way that there could be some kind of backpressure that is preventing me from moving fluid through it? Does fluid only move through them while the motor is running? Sorry, just scratching my head on this one...
 
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