Help needed in settings for starting an old Johnson Zobm.

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Johnson

18603C C480951

Hi everyone, i'm new to this forum and boat owning in general, i hope to make many friends long the way, and offer what little i have to aid others.

I bought an old Johnson 18603C 25 hp engine off ebay, vendor lived in Hull, i live in SE England, so a relation who lives up that way collected it for me, i have had to wait until recently for family meet up to get my hands.on it.

not a tale if Ebay woe as my relation did see it running, changing gears and squirt plenty of water during demo in a barrel as it should, but got no info or forgot any advice on how it should be started, and this where i need some tips.

I have messed with engine most my life, but this one has some designs i'm not sure of, the tiller has a start position which i select, i have a new external tank and Johnson connector. i prime up the fuel but not being sure how to set the square red slider (or what it does), or the round choke knob for starting on warm days, i'm getting nowhere fast.

Things i've tried -:
I have removed the fuel pump, this is pretty grotty but no sediment snd gauze is clean. The diaphragm is very stretched but not perforated (as far as i can see).

I have a 12 volt electric fuel pump, so i tried that in place of the original pump, having sussed this old pump is driven by crankcase pressure, and perhaps there might be an air leak, but to no avail.

i really need the basic starting tips for this old girl, any help is really appreciated.

Thanks for reading
Regs
Alan

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to update, now found be red slider is the choke (Doh!).

when i looked at the choke linkages i follow them to a roller that seem's should be affected by a cam (with yellow paint) that moves with the tiller throttle, just under the flywheel, but no matter what i try this roller never reaches this yellow raised area.

the centre round control seems to adjust a jet in the carb - is this a slow running control?

can anyone give me the points gap and plug gaps setting please? i know on this type of ignition system, the points gap is usually critical and the only way to adjust the timing correctly, be obliged if there us a timing mark to let me know as i have a tuning strobe gun, i just want this 1986 classic engine put back in tip top condition.