Primer solenoid

[powerabout]

Did any yams come with primer solenoids to richen start or they all had choke butterflys?

[pcrussell50]

Did any yams come with primer solenoids to richen start or they all had choke butterflys?

Good question. My 1986 40 has choke butterflies.

I’ll try to ask about next time I’m back in Australia where they sold these motors new until about mid-2020, if they went to an enricher.

-Peter

[powerabout]

Good question. My 1986 40 has choke butterflies.

I’ll try to ask about next time I’m back in Australia where they sold these motors new until about mid-2020, if they went to an enricher.

-Peter

They are still selling the 2 strokes in Asia and the 2 cyl 40 just the same as it always was
Plus the clone builders from China ( over 10 brands that I can see)

[CRH1]

Yes some of the mid range yammies came with enrichment solenoid. Late 90's to early 2000 they came with the square bowl carbs. The middle carb has the solenoid

[powerabout]

Yes some of the mid range yammies came with enrichment solenoid. Late 90's to early 2000 they came with the square bowl carbs. The middle carb has the solenoid

So it wasnt an external device like OMC?

[CRH1]

It is electrical but it works on a thermal principle. When you start the motor cold it's automatically enriches, for like 30 seconds, you have no control over it. Then the motor idles down and runs normally. Bill Grannis wrote a great article on how it works, I'll post it if I can find it

[cali kid]

It is electrical but it works on a thermal principle. When you start the motor cold it's automatically enriches, for like 30 seconds, you have no control over it. Then the motor idles down and runs normally. Bill Grannis wrote a great article on how it works, I'll post it if I can find it The smaller Yamaha triples use Prime start system. Injects fuel and enrichens with a tapered needle that closes as it warms up. Uses power from the stator only while running.

[CRH1]

Couldn't find the Bill Grannis article but this video explains how the system works. https://www.youtube.com/watch?v=Ln6SyBRaLUY

[powerabout]

Couldn't find the Bill Grannis article but this video explains how the system works. https://www.youtube.com/watch?v=Ln6SyBRaLUY
Many thanks, what a complicated system to replace what was simple

So its down to OMC or Merc remote fuel solenoid

[pcrussell50]

It is electrical but it works on a thermal principle. When you start the motor cold it's automatically enriches, for like 30 seconds, you have no control over it. Then the motor idles down and runs normally. Bill Grannis wrote a great article on how it works, I'll post it if I can find it

Sounds a lot like the enrichment on my 2000 Yammie F100 (Merc 90 FourStroke). I think they utilise some kind of wax or wax-like material that expands when heated. When you turn the key on a cold motor, a plunger is lifted that unports something allowing enrichment fuel in. It also unports an air bleed that increases the idle speed. As the pellet heats up and liquefies, it expands and starts pushing the plunger back down, closing off the air bleed and the enrichment fuel. It works really well, IME. Might as well be EFI, for how well it works. The enrichers screw to the side of the carbs. I don't think you can just add them to a carb that did not have them to begin with.

-Peter