S.l.o.w.?

[Jeff23]

Hi All-- can anyone tell me whether a 1998 50-hp two-cylinder Johnson engine has the SLOW feature? The engine runs like a champ most of the time, but on two occasions (latest one was today) it won't run at the upper end of the throttle;i.e., can't plane the boat, but engine is fine at hull speed. Today I thought I heard a series of quick little chirps from the control box when it balked.

When this happens, it sounds like it's not getting gas and runs rough--almost like one cylinder is missing--three weeks ago had it to the dealer who sold it to me used-- they cleaned it out and said there was a fair amount of gunk in the carb. Possibly it needs a carb re-build and I was planning on having that done over the winter. But could it be the SLOW system kicking in?

Water stream is strong, and we had been drifting with engine off for about fifteen minutes, started up fine, went to plane the boat and the characteristic rough running, etc. occured. Oh, and I don't run it from the main fuel tank--I exclusively use a portable tank and hose--both new this year.

Maybe I should just shut up and get the carb rebuilt?

Thanks,

Jeff

 

[OBJ]

Re: S.l.o.w.?

Hey Jeff.....if the dealer told you there was a fair amount of gunk in the carb.....why didn't he clean and rebuild it then? His wrench would have had to look in the bowl to see this. To do this, you gotta remove the carbs. If they need rebuilt, do it now. Don't run them like they are and take a chance of running a hole lean and ruining a cylinder.

 

[Silvertip]

Re: S.l.o.w.?

First -- does the warning horn chirp when you first turn the key on. If not, get it fixed. You may be overheating and without that horn working you would never know it and yes, the SLOW function would engage. That warning horn also sound if you have a low oil, no oil, or fuel restriction situation. When it acts up, squeeze the primer bulb a couple times. If the engine takes off momentarily, you probably have a weak fuel pump. If there is no change, it's not the problem. Then try pushing in on the key momentarily. This activates the primer solenoid and injects extra fuel. If the engine takes off you very likely need some carb work. If it still acts up, a spark check is in order as the engine may be running on one cylinder. Power Packs do go bad.

 

[Jeff23]

Re: S.l.o.w.?

Hi guys, thanks very much for the replies. The horn does chirp when I turn the key and start up the motor. I squeezed the bulb, didn't make a difference. I also pushed the key in a couple of times, and the response was that it almost died, then ran through the extra fuel (I'm thinking) and ran ok at mid throttle (I don't have a tach). Didn't try it at full throttle though. I think there was a series of short chips when I fist gav it full throttle right before it ran rough, etc.

As far as I know the dealer cleaned out the carbs, but he didn't say anything about whether he rebuilt them or not. Probably not then, since he didn't charge me for working on it (I'd just bought it about three days before it started acting up). But I'll ask him.

Thanks again--this board is very helpful! If you have any more ideas, I'm happy to hear 'em

Jeff