Outboard stalls in gear under load

[TomasDelSol]

I have a problem with my 1987 50 HP outboard only when it's IN the water. If I have the boat in the driveway I can put it in gear and it runs fine... but if I'm in the water at the dock, if I put it in gear it croaks. <br /><br />I put in new gas, new plugs, new gas filter, sprayed carb cleaner and ran that through. It all seemed to improve how it ran in the driveway but not in the water. The fuel filter is full so I'm not sure it's a fuel pump problem... or is it?<br /><br />Any thoughts and help would be MUCH appreciated!!!

 

[fishingdan]

Re: Outboard stalls in gear under load

I have an '85 50hp. Unfortunately, it is hard to tell how an engine is really running without having it in the water where you can put a load on it. Probably a carb problem or you are not running on all cylinders. <br /><br />Is this a new problem? Has it run well recently?<br /><br />Does it stall only when you slowly move the throttle into forward? <br /><br />Just before it stalls, will it recover if you hit the choke?<br /><br />Can you get past that by quickly advancing the throttle? If so, how does it run at higher speeds?<br /><br />Do you know if you are getting spark on all cylinders? I picked up a small spark tester at sears for about $6 and now keep it in my boat tool bag. <br /><br />Have your carbs ever been rebuilt?<br /><br />I don't know if I can help you that much, but given my recent problems and resolutions, I know what kind of information is needed to help you diagnose the problem.

 

[TomasDelSol]

Re: Outboard stalls in gear under load

Thanks for the input, Dan. I just picked this boat up so this is the first time I've taken a crack at it. And, unfortunately, the conditions in terms of current and wind have left me stranded at the dock, because I am wary of heading off not knowing what will happen.<br /><br />What I think I'll do is slap my little 3hp dinghy motor on the back and go to a calmer place to give it a try.<br /><br />However.... if I just nudge the throttle into gear, it croaks. I will definitely try your suggestion and try to quickly advance the throttle and mess around with the choke. I assume that if the choke fixes the problem then I have a carb problem... right?<br /><br />It seems like all the cylinders are firing, at least in the driveway.<br /><br />I bought some fuel additive yesterday, so I'll also give that a try.<br /><br />Thanks VERY much for your input...

 

[fishingdan]

Re: Outboard stalls in gear under load

If pushing the choke helps the problem then at least you do have a carb issue. <br /><br />You can't really tell if the engine is running on all cylinders in the driveway. I have fallen for this myself. I swore up and down that it was running on all, but in the end, it was running on two.

 

[Laotzu]

Re: Outboard stalls in gear under load

I second fishingdan's thoughts. Your 50 is probably 3 cylinders. It will sound like it's runnning fine in the driveway but may be firing on only 2 cylinders. Pull the plugs and see if one of them is fouled ie: black and maybe oily compared to the other two which should be grey/tan colored. If so the fouled one is not firing. Since you just bought the boat, it may have sat for a while like my 50 did before I bought it. My problem was varnish flakes in one of the carbs which were sucked into the jet under load.<br /><br />Jerry

 

[Bob H.]

Re: Outboard stalls in gear under load

Split, clean, and adjust the carbs. Sounds like you've got some junk in the low speed circuit.