Yamaha 30 - Replace Ignition switch

Aug 7, 2025
10
Yamaha 30-1 Vancouver Island
I friends I need some advice.
On a recent trip the ignition switch for my yanmar 2gm broke and I can only start the boat with the manual crank right now.
I am looking at replacement options The part that is listed as an OEM replacement is https://www.marineoutfitters.ca/index.cfm?category=10025%7C11679%7C11615&product=85356560&code=124070%2D91250%20%20E

I have to wait for weeks and pay terifs /shipping so its gonna be close $200
but my local shop can get this one in today - https://www.westmarine.com/bep-marine-2-position-ignition...
my only concern is the amp rating. I cant figure out what the OEM part is rated for but what I do know is the ingition has a 30amp in line fuse on the live wire.
I am thinking its probely not a good idea to have a 10amp switch on the other end. But I am not sure if thats from Yamaha or an old owner using w.e they had on hand.

Can anyone confirm if they are fused with a 30amp fuse as well.
or any experience with replacing the switch? to something rated for 10amps?
the In line fuse is behind panel accessible from the aft quarter berth

1758304533890.png
 
Aug 7, 2025
10
Yamaha 30-1 Vancouver Island
okie that makes sense. Thanks all. And to switches normally come in 10amp or 5amp versions?
 
Jan 4, 2006
7,320
Hunter 310 West Vancouver, B.C.
I used a Cole-Hersee switch from the local Auto/Boat Parts store.
Same here. This is as good as you'll find.

Your 2GM starter relay will pull about 20A when starting. The starter relay and starter motor will pull :

1758310772767.jpeg


............. when they are cranking.
 
Jun 8, 2004
2,970
Catalina 320 Dana Point
The switch only has to power the starter solenoid which carries the heavy load of the starter.
https://www.littelfuse.com/assetdocs/m850-datasheet?assetguid=2dc84f3e-3a36-4e0e-8432-81c67e44e7b4
https://www.littelfuse.com/products...es/ignition-switches/marine-ignition-switches
Most of the Yanmar GM's use the same "B" key so they provide little security really, you could just use an unkeyed switch. That's what we used on the fire engines, that way nobody forgot and took the keys home after work.;)
 
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Sep 24, 2018
3,652
Catalina 30 MKIII Chicago
I dont see a single wire in there that could handle 30A long term. I think I see one 12 guage that would handle the 20A load that you speak of
 
Aug 7, 2025
10
Yamaha 30-1 Vancouver Island
Thanks everyone for the amazing advice, I am on the hard doing some work on the hull so it worked out this happened on the sail over. I ended up finding an oem part at a local mechanics for a decent 140CAD so i went with that.