WOT adjustment and WOT rpms

[Proselect]

I have an evinrude 112 spl. Looking at my carb linkage at wot, they are not quite at 90 degrees. I would say anywhere from 85-87 roughly. Is that really enough to affect the top end rpms? I just redid the lync and sync tonight and got it right on the money now at 90 degrees. I am just wondering if I should expect to see change or not and if that little bit really makes a difference or not. If not, than at what point would it make a difference?

Also, the engine seems to run great, other than lacking some top end rpms(I know its mostly the prop). I am not having issues idling, starting, or running at any range. Do I bother rebuilding the carbs for maintanance then? Would I gain anything at this point?

Lastly, the plugs are a little dark. Like I said, no running issues, but does it help to change out the dirty plugs even though no driveability issues?
Thanks in advance.

 

[Proselect]

Re: WOT adjustment and WOT rpms

Ttt

 

[archcycle]

Re: WOT adjustment and WOT rpms

I have an evinrude 112 spl. Looking at my carb linkage at wot, they are not quite at 90 degrees. I would say anywhere from 85-87 roughly. Is that really enough to affect the top end rpms? I just redid the lync and sync tonight and got it right on the money now at 90 degrees.

What are your top end RPMs? What is your boat and setup? prop pitch? running conditions and load?

Also, the engine seems to run great, other than lacking some top end rpms(I know its mostly the prop). I am not having issues idling, starting, or running at any range. Do I bother rebuilding the carbs for maintanance then? Would I gain anything at this point?

You can lack top end RPMs due to a high speed jet being partially or fully clogged. My experience with the top end RPM issue is that tons of things affect that.

Lastly, the plugs are a little dark. Like I said, no running issues, but does it help to change out the dirty plugs even though no driveability issues?

Spark plugs are not expensive in the greater scheme of boat maintenance. If you don't know how old they are, just replace them so that you do know.

 

[DargelJohn]

Re: WOT adjustment and WOT rpms

"Looking at my carb linkage at wot, they are not quite at 90 degrees. I would say anywhere from 85-87 roughly. Is that really enough to affect the top end rpms?"

This will effect performance. Don't know what year model you have, but the pins on the outside of the butterfly shafts need to be perfectly verticle. Adjust the throttle stop bolt/nut (circled in red).

 

[bob johnson]

Re: WOT adjustment and WOT rpms

are the throttle plates fully opened??? ie ..are they 90 degrees to their bore???


if not , then you have more adjustment to do.


once the plates are fully oopen and your motor is running great and the timing is good....only the prop and boat posture can change your WOT rpms

good luck

bob