Atomized fuel going the wrong way - 140hp Johnson 1985

[Bobby D.]

The problem started when fishing, the RPMs dropped from 3600 to 1200 and then stalled. Later, checked the compression 85psi to 105 psi. I decided to decarb and rebuild the carbs. When I removed the front carburetor cover oil was laying in the bottom of the cover about 4oz. The VRO was disconnected at the beginning of the season and I mix my own 50-1. With the carburetor cover off and muffs on the water intake I started the motor and noticed puffs of air and fuel coming from all four carbs.<br />Not alot but enough to know something was wrong. My guess is that the timing is off. What else could it be? Is this motor easy to time? If that is my problem. Thank you

 

[G DANE]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

Hi Dude<br /><br />Behind your carbs there is a reed valve block, with thin leafblades, shutting airstream off in the intake process, in order to keep intake in cranckcase. You most have broken or chipped a leaf, or more likely, if some thru all carbs, the bolts that holds the block came loose. You will have to pull carbs and take a look at the reed assy. If you are missing blades, they must be found before they reach a cylinder and damage piston and bore. If your motor has bypass covers, it can bee behind there.

 

[R.Johnson]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

Pull the cylinder heads, and take a look. 20 lb. difference does'nt sound good.

 

[Forkin' Crazy]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

I am thinking a minumum of 10 psi difference. You might have stuck rings.....<br /><br />If it is blowing fuel air out of the carbs it could be reeds, but unlikely one in all four. It is a crossflow or a looper? '85 or '86 is where they changed on the 140. Also started rating at the prop instead of the flywheel.<br /><br />FC

 

[Joe Reeves]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

The timing could only be wrong is the flywheel key sheared. If you've had the flywheel off and did not torque the flywheel nut to factory specs, the key will absolutely shear.<br /><br />However, from what you've said, there could be bigger problems.... but check the key first.

 

[Bobby D.]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

Thank you guys for your response's. Joe R. I had the stator replaced about 100 hours ago. If I remove the flywheel nut from the crank can I see if the keyway in the flywheel does not align with the key in the crank? Craz, I don't know if this motor ia a looper or a crossflow. The model # is J140txco. I'm not sure what the "t" stands for. If I want to check the timing I assume I can use an automotive timing light and the manual sez 22* BTC

 

[G DANE]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

Hi again Dude<br /><br />You will not be able to see cranckshaft keyway from under nut. If you check timing with automotive tester, at cranckning rpm, which is as good as any, expect fully advanced timing to give 18 deg btd instead of 22 as the 5500 rpm will provide the last 4 deg. Good luck.

 

[Joe Reeves]

Re: Atomized fuel going the wrong way - 140hp Johnson 1985

The 1985 120hp or 140hp Evinrude/Johnson is a Loop Charged (looper) engine.<br /><br />The flywheel must be removed in order to observe the key. If sheared, the flywheel and crankshaft tapers will require cleaning up.<br /><br />The flywheel nut must absolutely be torqued to 145 foot pounds, otherwise the key will shear.