2.3L OMC WOT Problem

[jkgregg]

i have read the sticky and followed some of the recommended checks. i am at the point that the prop or gears are wrong. to start off, this is what i know: newer manufact motor (comp test is all cylinders at 160psi), brand new carb, fuel pressure is 5psi, timing is dead on (even underload), great spark (shocked the hell out of me at every plug), bought new fuel pump, blew out the pickup tube in the tank, cleaned out bad fuel in tank, and replaced fuel filter.

after all that i am still having some issues with WOT. when i have the flame arrestor off, i have to manually (completely) open the top butterflies on the carb in order for it to get up to 3000 rpms and run smooth. i have heard that this motor runs up to 5000rpms and i have a lot left on the throttle. the speedo says 27mph. surely this thing goes faster.

also, the oem prop is 13 3/4 X 15 degree. i found one locally that is 13 1/4 X 17 degree and that is what i put on it. is that enough diff that that is the root of my problems?

also, if it is something with the gears is there an easy way to determine the gears i have?

thanks,
james

 

[Gary H NC]

Re: 2.3L OMC WOT Problem

The top butterfly of the carb is the choke.It should stay completely open when the engine is warm.

The prop pitch change will not cause you to lose 2000 rpms..more like 200.

 

[Bifflefan]

Re: 2.3L OMC WOT Problem

1st
the top butterflies are the chock, not the throttle plates. is the chock working properly, ie: closed when cold, open completely when warm?

2nd
is the timing advancing properly with incresed rpm's. ie: are the weights rusted in place or not moving enought?

 

[jkgregg]

Re: 2.3L OMC WOT Problem

the top butterfly does not stay open completely when warm.

bifflefan, i am not sure what you are trying to ask. i put a timing light on it when i was out on the water with a full load. i moved the distrib around until i thought it was running smooth with about 75% throttle. the timing is now around 18. i dont know what you mean about the weights rusted in place.