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50Hp Johnson idle issue

K

kevsworld

New member
good morning,

searched the threads, but need a little more advice on my specific issue...I called around town and cannot find a mech willing to work on the motor, and the few that will are 1-2 weeks out. I'm not the best mech but I can follow directions well.

I have a 1982 Johnson 50hp 2 stroke - its a little hard starting when cold, starts fine after warming. The idle seems OK after initial start, it backs away from the dock and goes into gear smoothly.

The motor responds well to the throttle and runs great wot. There is no problems when running at no wake speeds either...the problem comes when I shift out of gear into neutral.
The idle is low,,,then it just dies. It is hard to start the motor after this happens and when started, smoke billows out,then clears, but it is near impossible to get it moving again as it dies when put in gear. I have to have the engine rpms up to engage the gear to get going again.

It runs perfect on muffs, but after reading many posts, that is not surprising.

any and all help is extremely appreciated, thanks in advance,

Kevin
 
You may just need to bump up the idle speed.----But you might want to do a compression test on that motor.--------Those high winding 2 cylinder motors have been know to score the pistons.---------Perhaps there is a fuel leak in the carburetor or the fuel pump.Does the bulb go hard when you squeeze it ?
 
Start with the trouble shooting basics.

Spark plugs should be Champion QL77JC4 plugs gaped at either .040 (Original recommended) or .030 (Revised gap). Whichever one you're using, try the other.

What is the compression psi reads of the individual cylinders?

Spark (with plugs removed) should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it?

If the above areas are as they should be, remove, clean, and rebuild the carburetors.

Cold engine starting procedure: Fuel primer bulb pumped up hard, throttle advanced slightly to take engine off dead idle setting, turn key to START position and engage choke or fuel primer solenoid by either pushing the key in or activating a separate toggle switch. Engine should start within six (6) revolutions), after which release the key to have it return to the RUN position.

Is the above your cold engine starting procedure?

You can check the fuel pump diaphragm as follows:

(Fuel Pump Diaphragm Test)
(Two Hose Type Only)
(J. Reeves)

Note: This pertains only to the regular Two Hose type fuel pumps.

Leave the hoses attached to the fuel pump. Remove only the two screws that attach the fuel pump to the powerhead. Re-insert those two screws and install a nut to each of them so that the fuel pump is securely clamped together. With the fuel line attached to the engine, pump the primer bulb while observing the pressure/vacuum operating hole on the back side of the fuel pump. Should any fuel leak out that hole, the diaphragm is faulty.

If the diaphragm is faulty, the fuel pump will require rebuilding or replacing. Note that repair kits are not available for all fuel pumps, in which case replacing the pump would be necessary.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:
http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
 
Hi Racerone,

the bulb gets hard when priming, I have not noticed any gas leaks The compression according to the previous owner was 130-128.

after it stalls when idling in neutral, I pumped the bulb but it is soft and does not get hard like the initial start.
 
Hi Joe, thanks for reply,

this is my first electric start motor, so I will try the starting procedures you mentioned. In looking over the fuel line, I did just notice the fuel line entering the the fuel pump, filter, (?) is wet, and has a slight leak when I pump the bulb. It is secured with a zip tie, so I will replace that with a worm clamp and tighten. The lines are all new so they are in good shape. Could this be the reason for my issues?
 
What is the compression today ??----Have you installed a new impeller or did the previous owner say it was working just fine ?
 
Racerone,

I just completed a compression test and found the top cylinder at 130 and the lower at just under 130. The impeller was just replaced in Oct last year, and it has a strong stream.

I also found the fuel filter a little loose, it was barely finger tight, with the fuel hose entering the filter having a slight leak under pressure. I tightened both, and about to change the fuel bulb.
 
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