Primer AND Choke??

[phil-b]

I always thought primers and chokes on carbs were a "pick one" kinda thing (old and new), until I got a Martin 40 (I’ll admit, my oldest outboard) which has BOTH.

Are there many engines with both?

[donsmarine]

do primer(squeeze) bulbs count

[phil-b]

quote outboardfix:

do primer(squeeze) bulbs count

I meant things that over-fill the carb (for example, by pushing down on the float)

[frankr]

I had forgotten those Martin choke/primers until you mentioned it. Once you get the hang of it they often will cold start on one pull. Unless you have money riding on the bet.

[phil-b]

So if Martin was unusual to have both, I wonder why?

Did the poppet valve induction make it harder to start?

[rudderless]

I rebuilt one in 1980, rings were 1.5 diameter x 1/8 cross section. I made a new water pump out of a hockey puck and a band saw. Gear case uses grease. I had carb issues so I put on a carb off of a chain saw, Lawson diaphragm carb If I remember. Ran real good with that carb. Mix at 16/1.

Thats all I got on the Martin 40.

Oh..it started on first pull with the Lawson carb..wasn’t bad with the stock carb either..

Last thing..I figured the real light valve springs would let the valves float at high speed increasing valve timing at high speed..

[frankr]

quote Phil B:

So if Martin was unusual to have both, I wonder why?

Did the poppet valve induction make it harder to start?

If you think about it a lot of carbs have some enrichment device other than a primer or choke alone. A couple come to mind offhand. Gale motors open the high speed needle along with primer actuation. Some (Scott) open the high speed needle along with the choke actuation. OMC kicks the throttle butterfly open when choke knob is pulled (to apply more suction ahead of the choke). Choke motors usually require a couple of pulls to suck fuel from the carb and draw it into the crankcase. Primer carbs dump it into the crankcase without any rope pulls. So, you can rationalize that Martin was using the best of both worlds. BTW, notice that in later years, OMC got rid of chokes and uses primers?

I don’t think Martin’s poppet valves had much if any effect on cold startups.

[donsmarine]

quote Phil B:

quote outboardfix:

do primer(squeeze) bulbs count

I meant things that over-fill the carb (for example, by pushing down on the float)

I understand, just trying to make a point. You mean a motor like a British Seagull. Also those style carbs on some British m/c.

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