1996 Johnson 50 HP J50DTLEU Problems

[danielnn]

I got this motor last year, rebuild carbs, lower unit replaced all fuel hoses added water separator and by-passed VRO, mixing gas 50:1 with ethanol free gas since rebuild. Motor has ran like a dream I try not to go above 4000 rpm it pegs at 5000 rpm and makes boat fly, so far loved this motor. Last time on lake it lost power would not go above 2500 rpm and stalled on me constantly at low RPM's. Also notices it was leaking gas in the lake as if it was running too rich or going right truw the system, removed cover no gas present on engine or carbs. Changed plugs I use the Champion QL78YC put it back in the water same issue. can it be a simple carb adjustment or do I need to rebuild again, rebuild kits are only $16 a piece but it worried me when I saw how much gas it was putting in the lake went thru 3 times as much gas as normal, please advise.

Thank you much for any help.

 

[flyingscott]

Is the primer working correctly did you turn the red lever at all. If not do a cylinder drop test sounds like you are flooding or running on one cylinder.

 

[danielnn]

I still have to test the primer. I haven't turned the red lever at all meaning it is not in the manual position. I just completed a compression test 70 psi cylinder 1, 70 psi cylinder 2, 68 psi cylinder 3. Completed a spark test, spark is good on all 3 plugs. The cylinder drop test was a bit tricky, on idle: Number 1 no noticeable difference. Number 2 you can really hear the difference, wanted to stall. Number 3 engine died. Should I perform the cylinder drop test at a higher RPM to see if I can hear the difference in number 1 or is it okay doing it at idle. One thing I did notice I had the lower unit in the big bucket with water, and it was spewing gas like crazy. I'm going to remove the primer and test it to see if it stuck open I'm also going to check if maybe the ignition switch is bad and maybe sending a signal to the primer to stay on. Question, is this so far an indication of a gas problem or should I look further into the cylinder 1 on that drop test being that I didn't really notice a difference on idle. Please let me know before I take apart the carburetors. I'm still a newbie at all this, can something be bad in the carbs that could be causing it to spew out so much gas and run so rich to the point of flooding. Again thank you to the community for any help.

 

[flyingscott]

That compression is way to low re-test with a different tester you need to be above 100 PSI.

 

[ondarvr]

If you don't see a difference when removing the plug wire on 1, then there's an issue with that cylinder. At this point it could be spark or carb related, if the float is stuck it can flood that cylinder and cause it not to fire. But if there's no spark the fuel will go straight through and you'll see it in the water, so there's about the same visually affect either way, a bunch fuel in the water.

 

[danielnn]

flyingscott
I always thought that it would not matter how low it was as long as they were close to each other. My tester might be off (Harbor Freight cheapo) but the results are close to each other.
ondarvr
I got nice spark on all plugs I will take apart carbs and check floats. Thank you both for the replies.

 

[flyingscott]

Your motor needs a certain amount of compression to run correctly at some point it becomes to low you are at that point. Exchange your compression tester for a different one and retry new your motor would have had around 150 psi new. You would not be the first person to get a bad tester from harbor freight. If that turns out well then do what ONDARVR said to do

 

[racerone]

Remove the cylinderhead for an inspection.

 

[Silvertip]

Improperly installed needle and seat, float level incorrectly set or fuel saturated float(s) can't float.