1959 18hp sea horse tuning

[cbigs]

Hey, this is my second boating season, i bought this motor rebuilt last spring ready to go .

Towards the end of the season the high and low mixture needles got out of wack, and i was having a hard time running it at very low idle. Also, when i would start it up, it would accelerate, then it would shut off if i didnt put it in gear and go

Does anyone have any suggestions for re-tuning the engine so it can idle very low, and starts up nice and smooth? Anything would be very appreciated

 

[HighTrim]

Re: 1959 18hp sea horse tuning

That motor is complete JUNK, send it to me immediately and I will properly dispose of it for you.

Kidding of course, exactly the motor I am currently looking for. There are many guys on this forum experienced with that vintage outboard.

When were the carbs last rebuilt? Have you checked the spark and compression?

Will spraying pre mix into the carb throat pick it back up? Priming the fuel bulb?

There will be a thread in the FAQ here on iboats by Joe Reeves on setting the needles. Well worth a read

 

[wbeaton]

Re: 1959 18hp sea horse tuning

Looks like I'm following you today, Hightrim.

Since you say the mixture knobs got out of whack I'd start there. Reset them using Joe's procedure. The starting position for the jets is 1.5 turns out on the low speed and 1 turn on the high. You can't set it running in a barrel. Has to be on a boat.

 

[cbigs]

Re: 1959 18hp sea horse tuning

where can i find joes procedure?

when you say turns out, does that mean i should turn both knobs one direction till they stop, and then turn them the recommended turns....clockwise counter clockwise?

I should just do it when i put it on the water so that i can let it adjust? Thanks

 

[cbigs]

Re: 1959 18hp sea horse tuning

ha, you got to love the old outboards. it was rebuilt in 02, and stored since. it runs great just wont idle low and makes it a little trickier starting...got to get it tuned in.

 

[jbjennings]

Re: 1959 18hp sea horse tuning

Sounds to me like you need to tighten your packing nuts so they won't drift out of tune. That will make your knobs harder to turn and less likely to move. Yes, you need to tighten the adjustment knobs clockwise until they LIGHTLY seat. Don't overtighten as it will booger up the tips of the valves. Then back them off and make final adjustments on the lake like everyone said. I like to get mine wide open and find the sweet spot then barely back it off to be sure it's not too lean.
Just my opinion,
JBJ