1956 Evinrude Big Twin 30hp

[Westopolis]

The boat is a 1957 15' Seafarer with a 1956 Evinrude 30 hp.
I recently purchased the boat. Rebuilt the lower unit and I'm sorting through the minor glitches. My latest consern is I can not get the motor over 2000rpm with a top speed of 15mph. I have adjusted the throttle and everything seems to be ok.
Does anyone have idea what could cause a maximum 2000rpm?

 

[kfa4303]

Re: 1956 Evinrude Big Twin 30hp

Hi West. Cool old motor you've got there. I bet you a nickle you're only running on one cylinder. Make sure you're getting a consistent spark capable of jumping a 1/4" gap. Make sure you're using Champion J6C or J8C plugs as well. Here are some handy links.

Reviving a Vintage Big Twin - Part 1

http://www.marineengine.com/parts/vintage-evinrude-johnson/ITEM_2750/ITEM_275000001.htm]Vintage Evinrude Johnson Outboard Parts & Diagrams - Catalog ITEM_2750[/url]

 

[bonzoscott]

Re: 1956 Evinrude Big Twin 30hp

Not sure what that boat is. Is it fiberglass? You may be over propped. I suppose you have a tach where you're sure of that RPM? Other than that, make sure it's running on both cylinders.

 

[bonzoscott]

Re: 1956 Evinrude Big Twin 30hp

THEXTON 404 THX404 ADJUSTABLE SPARK TESTER - YouTube

 

[HighTrim]

Re: 1956 Evinrude Big Twin 30hp

Start with the coils. If they are the originals they are junk. Pop the flywheel and time to have a looksee.

Have you kept the original 6 volt setup or are you running on 12 volts?