Issue with 6HP Johnson Seahorse

[viper1216]

Good morning!
I picked up a little 6hp engine for my inflatable and having an issue with it. First thing is figuring out what year it is. I have been looking at the serial number (see attached) and trying to match up, but it doesn't seem to fit the layout of letters and numbers in the charts when I try to look it up. That's making it hard for me to even begin to look up issue. The issue I am having is that when I go to give it the gas to go, it just has no power. I can feel like it wants to go, but it revs up and then just sounds like it's bogging down. I put new plugs in it, cylinder compression on both cylinders is 80 and I have spark to both plugs. I really don't have a heck of a lot of experience with outboards, so a bit lost as to where to begin. There is what appears to be a mixture control on the front of the motor that I assume is some sort of air fuel mixture. It has a hard time idling if I turn that up. Trying to find a manual or something to point me in the right direction and maybe where the carb adjustments may be, but without knowing year, I'm kinda in the dark. Any help is greatly appreciated!!!! Thanks!!

 

[viper1216]

Ok, so I think I found the model and year....what I thought was a G is actually 6. So it appears this is an 85.

 

[racerone]

1985 model.---Need to install a new water pump impeller.------Pull one plug wire off at a time and try to start it.-----Or do that with motor running.----Report what you find.----Does primer ball go hard ?-----Did this motor sit for a long time , as in years and years ?

 

[viper1216]

Will do. Thanks!! Yes primer ball is hard, it did sit for a few years, but I believe it was gone through before I bought it late last year. I know impeller was replaced and I thought he said carb cleaned or rebuilt, but I will double check that.

 

[viper1216]

Ok...had some time to work with it this weekend. One plug off at a time causes it to run rough like it's on one cylinder. Both on, idles like a champ. Replaced the fuel pump. Still same issue. Runs great at idle and low speeds, as soon as I whack the throttle, it just bogs out. Even tried bringing it up slowly, as soon as I get to about 3/4 throttle or so, it seems to just bog down as has no power.

 

[racerone]

Not sure why folks throw fuel pumps ate these motors.----They are so simple and reliable and a new diaphragm is all they could need.-------So I suggest you clean the carburetor.----Find the tiny jets ( orifice holes ) and make sure they are clean.

 

[viper1216]

Honestly, I was just going to rebuild it, like you said very basic. But I have been monkeying with this for a bit now, and though I am pretty mechanically inclined, didn't want to mess something up with it, and it really wasn't that expensive vs the rebuild kit. Just 2 screws and a couple of hoses and I know it's right. If I had just rebuilt it, I would be wondering if I did something wrong right now. Sometimes peace of mind is worth a few bucks more. I'll give the carb a shot next. Thanks man!

 

[Crosbyman]

the pump is basic... but orienting the innards is daunting the first few times .... see doc. read 3 times !!

Rebuilding the OMC Fuel Pump

lay out the parts in exact order to keep the rebuilding process simple.
or buy a new one... I have use chineese copies with success. some don't like China stuff....
final test ....
air should blow in to out never out to in !!