Joe Reeves - can you make any suggestions

[jpbramlett]

I have a problem with my 1984 Johson 50HP (20"shaft/remote control). When I first start it up it idles fine. Once I've run under throttle, I have to lift the cold start up every time to get it started. Once the cold start is dropped I have to get it into gear and under throttle quick or it will stall. <br /><br />I tried increasing the idle and it hasn't helped. I've checked my compression(good 113/115 psi), plug gaps (.040), rebuilt my fuel pump (heard small holes in diaphram could cause similar problems) and had the boat tuned up completely about three months ago (It ran fine for a while after the tune up). It has a fuel water separator on it and I go through a tank of fuel at least every two weeks, so it shouldn't be a stale fuel problem. It doesn't seem like there should be a problem with the carbs(they were cleaned/rebuilt during the tuneup). <br /><br />Timing problem maybe? Any suggestions? Thanks in advance. <br />JP Bramlett<br />Pensacola, Fl

 

[Joe Reeves]

Re: Joe Reeves - can you make any suggestions

JP... Lifting the cold start lever, or giving it a little throttle without putting the engine into gear to restart is normal. I have a habit of doing that subconsciously. Restarting at a dead idle is something I just don't care for.<br /><br />What you are describing is a engine that is not running properly after it has warmed up. I could only suggest that when the engine is not running properly, to re-check the compression and the spark.<br /><br />The possibility exists that the stator is failing, and after it heats up, the voltage to the powerpack drops, resulting in erratic faulty ignition. The spark (with the s/plugs out) should jump a 7/16" gap with a strong blue flame on a constant basis.<br /><br />If memory serves me right, I remember the compression on that model to be up around 150 psi, possibly slightly higher. Do you ever recall it being higher?

 

[G DANE]

Re: Joe Reeves - can you make any suggestions

Only for information, I'v got a 1988 40 Hp it reads 148 150 compression. Yours seems a bit low.

 

[jpbramlett]

Re: Joe Reeves - can you make any suggestions

According to my Clymer manual, normal good compression for that model is between 100 and 120 PSI. I don't know if they're right or not.<br /> <br />I'll check the spark jump when the motor is warm. I readjusted the linkage and timing yesterday to the standards in the manual. Today I'm going to take it out and see if it helped out.<br /><br />Thanks for all your good information. Joe, where are you from in central Florida? I grew up in Crystal River - on the gulf side.