Topic: 1956 Evinrude 30hp pump conversion help – Antique Outboard Motor Club,Inc

This topic has 12 replies, 7 voices, and was last updated 6 years, 7 months ago by bigtrains.

Viewing 10 posts - 1 through 10 (of 13 total)

1 2 →

Author

Posts
September 7, 2017 at 1:31 am #8153
bigtrains
Participant
I’m brand new to this board and I hope someone can help. I acquired a 1956 30hp almost for free while picking up a Lark for my 1958 Lone Star runabout. I love the way the 56 looks. It has spark and is a bear to pull, so I’ve got high hopes that the compression #’s will be solid. I want to convert the motor to single fuel line. My question is which part number Briggs and Stratton or Mikuni pump will supply enough fuel? I can drill and tap the intake cover for a nipple. Thank you in advance!
September 7, 2017 at 3:22 am #64447
davesko
Participant
Welcome, I would seriously consider not doing a conversion. Get yourself a pressure tank and use it. That’s a great motor, I have one myself and love it. Make sure you change the water pump and do a go through on the ignition and carb. I’ve never been one for conversions. I’ve heard some horror stories when they are done wrong. A pressure tank can be gotten reasonably. Good luck.Dave
September 7, 2017 at 3:30 am #64448
bigtrains
Participant
I’ve given quite a bit of thought to the conversion. The boat is set up with single line and I’ve never seen a pressure tank in usable condition locally. By the time I find a tank, get it clean, renew the gaskets and o-rings, I could have purchased a few pumps. I work on very high pressure common rail fuel systems on locomotives. I’m confident that a conversion can be done and safe.
September 7, 2017 at 10:09 am #64453
chris-p
Participant
The conversions are fairly easy on the Big Twins. Ive done alot of them. Also, easy to put back if you ever want to. You wont be doing any UN Reversible!

I have never tried a Briggs or Mikuni on the Big Twins. I have used them on the 10hp and down conversions though. I suppose as long as they have a high enough GPH rating, you should be fine. At least 3 GPH.
September 7, 2017 at 11:10 am #64455
bigtrains
Participant
I don’t mind drilling/tapping the boss. My concern was which pump to use that will keep the bowl full. I plan on situating the fuel tank in the original spot which is next to the transom.
September 7, 2017 at 11:50 am #64457
frankr
Participant
US Member
I have never personally used either one on a Big Twin. I am kind of surprised that the B&S pump works at all on a two-stroke, but evidently it does. A Sierra 18-7353 (OMC 438555, 433386) is made for use with a pulse hose.

I have a B&S that I’ll give you for the postage. But not right now. Hurricane Irma is threatening to wipe us out. Send me a PM if we are still around.
September 7, 2017 at 12:40 pm #64459
crosbyman
Participant
Canada Member - 2 Years
http://www.mikunioz.com/shop/df52-745-f … 2439316-s/

dirt cheap some are just 15$ in the B&S name )(same pump)

good for 14Liters per h or…. 3gph

Attachments:

Joining AOMCI has priviledges 🙂
September 7, 2017 at 4:18 pm #64475
phil-b
Participant
quote Bigtrains:

… My concern was which pump to use that will keep the bowl full.

At least on the smaller engines, the bowl never stays full. I was expecting Frank to point this out. Are the big twins any different?
September 7, 2017 at 4:21 pm #64476
frankr
Participant
US Member
Expectations met. Yep, don’t expect the glass bowl to stay full. I thought he was referring to the carb float bowl.
September 7, 2017 at 6:00 pm #64483
bigtrains
Participant
I am referring to carb bowl. I don’t care too much about the sediment bowl.
Author

Posts