wot

[brian3127]

i have a 1975 40hp johnson serial number 40el75c
what should wot be

i ran it this weekend and it ran about 3700 to 3800

 

[Watermann]

Re: wot

5200-5500, isn't there a serial tag with that info on the starboard side mount?

 

[brian3127]

Re: wot

really, wow well im not getting that much.
i machined the heads last week new head gasket, new water jacket gasket, new plugs set at .030, new condensors, new points set to .020,and carb rebuilt.
i also did a link and sync.
what could be the problem

 

[brian3127]

Re: wot

the reason why i did this is because it was running real bad stall all the time. Then i was told posting a pic of the spark plugs that it looked like water was getting in to the bottom cylinder so i milled the head down new gaskets. I thought everything ran good i guess it could run better. alright all you johnson pros. what do i do next.

 

[Watermann]

Re: wot

I'm not an expert but normally the RPMs are dependent on the pitch of the prop if everything is set correctly. Although first off I would be sure that your throttle is opening all the way, take a look inside the carbs at full throttle and see if the butterflies are fully open.

 

[Silvertip]

Re: wot

What is the prop diameter and pitch. 40 HP on that heavy boat is a real load for that motor. continue to run WOT with those low rpm and you will toast the motor in short order. Are you certain it is running on both cylinders?

 

[brian3127]

Re: wot

im still waiting on a guy from work to bring me his compression gauge in so i can check both cylinders.
i pulled the plug wires while it was running and i cant remember which cylinder was better running i will have to check that again.
but there was a big difference when one was pulled compaired to the other. pulled one and it spit and sputtered. then i pulled the other and it ran like nothing happened.