Carb on 1958 10hp seahorse

hi, got a 58 seahorse, Model:QD19 serial: B2477, have replaced coils, checked water pump etc all the normal things you do to a old engine when you get it, including altering from the pressure cruis-aday tank system to a suction line ( a tank over here is impossible to source )

She starts and runs, but need advice on basic slow and fast jet screw settings before i strip carb so when i reassemble i have a starting point to then fine tune the carb to suit, also what mixture should it be run on? as i have seen several conflicting forums going from 16:1 through to 50:1 oil ratio,

regards

Neal

Re: Carb on 1958 10hp seahorse

Use a 25-1 fuel mixture. Set the needles' 1 1/2 turn's off the seat, or from full closed position. Turn top, or low speed knob until engine start's to make a lean, or cough back sound. Turn out to where engine run's the smoothest. Turn bottom, or high speed needle in until engine run's the smoothest, and fastest.

Re: Carb on 1958 10hp seahorse

hi, thanks for the fast reply, so to get this right,
1) set both needles 1.5 turns from lightly seated
2) with engine running alter top (slow) speed needle in or out till she starts to cough then back to smoothest speed
3) alter bottom (fast) speed needle in or out till smoothest running setting

I guess that i carry out at the start position on the throttle when starting the engine ( fast tickover in other words)

really do appreciate the advice, only thing i hated doing to the old girl ( i like to keep original where possible ) is converting from the cruise-a-day system, but over this side of the pond it is near impossible to get older parts, and the marine place i use last managed to get a pressure tank 10 years ago, and it cost over ?200 ( $300 i think ) back then.

regards

Neal

Re: Carb on 1958 10hp seahorse

Once you get her idling fairly good, take her out and run at full speed. Adjust the high speed needle to optimum. Then idle down and do the same for the slow speed needle.