'54 evinrude bigtwin 25hp

[jbjennings]

Well, I've run about 1/2 a tank of gas through my bigtwin. It is very finicky. I believe it is running hot although it makes a LOT of water out the exhaust. I have never cleaned the water jackets and the motor has sat unused for a LONG time from what I can tell. I have put new coils and condensers and cleaned/adjusted the points. I have cleaned the carb and got it to running pretty well idling and wide open. It was hard as heck to crank cold and the carb kept acting like the float might be sticking every once in a while. On wide open it has a tiny miss every once in a while--a short hesitation. Sometimes it doesn't but most of the time it does. I decided to clean and use the new carb I got with my new lower unit and use the brand new float I had ordered a couple of weeks ago. After installing it and adjusting it it ran pretty good even on wide open with not much hesitation at all, most of the time none. then on my second trip this evening it started acting crazy sometimes. whenever I would back off the throttle from wide open and slow to a stop it would start running crappy unless I leaned out the high speed mixture almost 1/4 turn, then it would smooth out again. When cranking it cold, it takes 4 or 5 pulls before it fires on choke and when it does fire on choke, it dies before I can push the choke in and then takes 3 or 4 more pulls before it cranks.
Any ideas as to what problems this thing has?
thanks,
JBJ

 

[wbeaton]

Re: '54 evinrude bigtwin 25hp

I'm sorry to hear you are still having trouble with this old girl.

Sounds like the intermediate circuit is partially plugged or the high speed is set a little too rich. However, I know you have cleaned this thing well so perhaps its just in the settings. I had to set mine so the high speed was just slighty rich.

 

[samo_ott]

Re: '54 evinrude bigtwin 25hp

I'd rather have a bad running Big Twin 25 than no 25 at all!