Mcculloch 4hp no start

[john8504]

Hello all! I have acquired a 1968 mcculloch 4hp air cooled outboard that I am having some trouble with. Upon receiving, I was unaware that it had the incorrect carb installed and now I must make something work. I have gapped my points at .020 and I have great spark. However, after priming the cylinder with a little fuel, I cannot get it to fire off. Any info would be great!!

Much thanks!

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[retiredoz]

Got anything in the way of compression ? What’s your throttle setting when you try this ? If you retard the timing too much it won’t fire.
Usually these are pretty straightforward and reliable, but I would gauge from the general appearance that this thing has been idle a while. The first putt is sometimes the hardest to get, I might try using a more persuasive fuel (as in starting fluid or even carb cleaner).

[john8504]

Yes it has been in storage at a elderly mans house for many years and then sold at his passing. I have checked throttle in several positions and still nothing. The retarded timing could be it now that I think of it.

[john8504]

My big question is what position should I have the timing at? My mini mac 35 was 26 degrees ptdc. Are all mccullochs the same?

[retiredoz]

As long as the points are set at .020, you should be OK. I was just referring to the position of the throttle. These are pretty simple machines, but you do need adequate compression.
The book calls for Champion J18YC plug, set at .035. May not hurt to try a new plug…

[joesnuffy]

The lower fuel line on there looks a little long looking at the picture it looks like it goes below the carb bowl which I would think would mean the carb bowl might not be filling up with fuel as it should since it is gravity feed. Hope that helps.

Joe

[john8504]

The carb is not original to the motor so the position of the connections are rather inconvenient(hence the long hose). However, because the tank is higher, the bowl is full.

I couldn’t find anything on the spark plug. I’ll get that one tonight.

The compression is good at 90.

[retiredoz]

The carb should be a Walbro LMG, I’m not surprised if somebody tried replacing it (not my favorite). Try setting the needles – HS 1 1/4 turn open, LS 1/2-3/4 turns open.. If the replacement is something else, your mileage may vary, of course..

[john8504]

Yeah they put a mercarb on it that was way wrong. I have a tecumseh on it now

[john8504]

Do y’all recommend a specific carb for this engine that would work well?

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