I made a mistake... I do NOT own a Big twin 35. Need some part # help for 1956 30hp

[eclipseturbors]

Sooooo.... I asked last week about a spark plugs on a Big Twin 35hp. I ordered and received J6C's. I had also did some quick research and jumped the gun. I ordered a fuel pump and intake bypass cover to drill and tap. I have a few tap and die kits and had it knocked out in 5 min. The only problem was that I then realized my bypass cover was not going to fit. I looked up the wrong serial #. My CORRECT s/n is 25924 which appears to be an Evinrude 30hp motor. I tried to research the Mikuni and B/S pumps but some of the threads jump around with troubleshooting help. Does anybody have any experience with either or both and can provide part numbers? I'm not sure if an intake cover from another model will actually fit that I can drill and tap like the last one. So I guess I'm stuck with a new Sierra pump. I'm pretty sure I can get a B/S this week via Amazon, but I don't want to order any more parts with the expertise this board can provide. Thanks in advance!

 

[Chinewalker]

I've seen some where the cavities on the intake port cover were filled with JB Weld or similar epoxy, then drilled and tapped to accommodate the fuel pump.

 

[oldboat1]

You can do spark and compression tests on that motor without running it. Spark issues can be resolved, but bad compression may mean a rebuild. I would at least do a compression test before working on a fuel system conversion. (Maybe you've already done that.)

 

[eclipseturbors]

The motor has spark. It came with some terrible looking autolite plugs in it. For $5, I felt 2 spark plugs would be worth the investment. I haven't put my compression tester on it, but it takes about all I've got to get it around. I'm pretty confident it has at least 90psi in each cylinder. The previous owner said he used it on a fishing boat a year prior before the tiller gear broke in the handle. It's going on my 1958 16ft aluminum runabout with cable steering, so I wasn't worried about the handle.

 

[oldboat1]

Get compression numbers -- needs to be close to even between cylinders (remove both plugs for testing, and pull it over until the needle stops rising -- maybe four or five pulls). Need a sturdy stand for the manual Big Twins.

 

[eclipseturbors]

I'll grab my gauge from a buddy that borrowed it this week. I had my spark checker handy, and both cylinders lit it up. I still may go ahead and make sure the points are adjusted and in time. I troubleshoot high horsepower locomotives for a living, but I still have a soft spot for old motors. I've already got this motor hung on the boat so it's easy to get my feet planted on the transom when I pull. I actually have another Big Twin Lark. That motor looks more of a project than this one. Plus the styling of the 56 is awesome.

 

[oldboat1]

Yep. Pretty motors. Post progress (pics of the Lark would be good -- locomotives too!)

 

[eclipseturbors]

No Title

This is the on-going project. The Big Twin in the pic started making a wrist pin noise that I could never get pinned down. I didn't feel comfortable having the kids in the boat that could leave us stranded. Plus the boat leaked a little, paint was in really bad shape, and it was time to spruce her up. I actually just finished tuning up a mid 70's 55hp Chrysler and about to swap LU on it to make it a short shaft when I ran into an ad for a very cheap Lark. The 1956 was actually free with Lark. So now I have a few motor choices! Lol. The 30hp fits the boat far better. I just would rather swap the fuel system and keep the 2 plastic tanks rather than find a pressurized tank and try to rebuild a very old fuel system. I'm sure I can get a few pics of a Tier 4 4500hp GE when I get to work. Lol

 

[jimmbo]

The 56 30hp was reincarnated and returned to live another life as the Evinrude/Johnson 28hp unit in the early 1960s. a bypass cover from one of those should also fit your engine.

 

[F_R]

Nice thought, but no cigar. The 28 has the same hole pattern as a 35/40.

 

[jimmbo]

It does? :embarassed::embarassed::embarassed::embarassed::embarassed::embarassed:... I guess I should die a horrible twitching death for that error

 

[F_R]

I believe the 30hp bypass cover has a blanked hole that you can drill through and tap to 1/8" pipe thread. Then screw in a hose fitting to connect to a Mikuni or B&S pump.

 

[eclipseturbors]

No Title

Looks like this.

 

[eclipseturbors]

So, I'm guessing after a quick compression check, I'm stuck tapping the cover I have for 1/8" NPT nipple. Does anybody have a B/S number that keeps enough fuel in the bowl?

 

[oldboat1]

Have to say I would rethink going with a pressure tank, at least until you have the motor up and running. I've used them for years (single tank for many motors, if not into multiple restorations). Take along a plastic gerry can if you need to, refilling the tank as needed. You can convert to a single line system anytime, but better to do it with a running motor, imo.