'59 Elgin (McCulloch) 40hp fuel problem

[corvairkid]

I have a '59 Elgin 40hp.When going along at slow speeds,it runs ok but when I go full throttle,it just dies off. I can close the choke about half and you couldn't ask for it to run any better! It has a Carter model N carb.Any help will be greatly appreciated. Thanks

 

[steelespike]

Re: '59 Elgin (McCulloch) 40hp fuel problem

Have you tried to adjust the high speed mixture needle.Initial setting is 3/4 turn out from gently bottomed.You may have to remove the knob for the initial setting reinstall knob half way between rich and lean after final adjustment.If adjustment does nothing:::
Classic symptom of a dirty carb.Do a rebuild with special attention to cleaning all passages and jets.
If you suspect the system may be dirty from sitting for long periods you should check it for clean, good hoses,filters,connectors etc as well.

 

[corvairkid]

Re: '59 Elgin (McCulloch) 40hp fuel problem

Sorry, I forgot to mention that the fuel pump&carb have been gone through.I went to the lake yesterday & adjusted the high speed jet and it didn't seem to make a difference.The fuel pump seems to be working.I'm going to add a clear filter to the hose from the pump to the carb to see if it might not be able to keep up at high speed.I would really like to find a manual for this old motor,but it might be pretty scarce.I have a matching Elgin boat,motor&trailer which is kinda rare.Going to a ACBA show on Sat. 6-2. I really hope I can get it fixed by then!Thanks again!

 

[steelespike]

Re: '59 Elgin (McCulloch) 40hp fuel problem

The carb is often still a problem even after a rebuild. You need to be sure all passages and jets are actually clear.(prove it)
If the high speed adjust does nothing it is another indication something is still plugged in the carb.
You could check the pump by unhooking the line at the carb and crank the motor with it in a can.Gas should pulse strongly into the can.BE CAREFUL!

 

[corvairkid]

Re: '59 Elgin (McCulloch) 40hp fuel problem

Sorry for the delay,I think I have cured my problem! It seems that someone had stripped the threads out of the bowl bolt and replaced it with a longer bolt that would reach the threads that were still good.Evidently,they didn't know that the high speed jet sends fuel through the same passage that the bolt fits.Turns out,the bolt they used was too long and would block off the jet hole causing me to become bald trying to figure it out!Anyway,after a helicoil repair and the right bolt,problem solved! I just thought I'd let you know how it turned out! Thanks!

 

[steelespike]

Re: '59 Elgin (McCulloch) 40hp fuel problem

WOW! not a problem you would likely solve a nice catch.