1976 mercury 402 not going over 1800 wot

[Kimbajmann]

I have a 402 on my 14 foot Starcraft and have be having an issue. It idles great and advances to about 1800 smoothly, but that is buried at wot. There is no hesitation or stumble, just goes meed to 1800 and stays there. Prop is not too pitchy. I have checked for fuel line issues and found none and also ran it on external tank to same effect. I took a can of sea foam and mixed it with gas in a small tank and ran it on that as well as sprayed sea foam throu carb- got a bunch of gunk out and it did idle smoother and ran smoother but still stops at same rpm. I did compression tests on both cyl and got 125 on each so no comp issue. I then took it again to lake on trailer and put it in gear and wot it at the same 1800 mark and sprayed gas into carb an engine just bogged - no increase in tac.

I am leaning towards the stater being the issue as I do not think it is a fuel del problem as the spray into carb of fuel at wot did not increase rpm and the engine runs very smooth to that rpm and just stops there. I understand the staters in these have a high and low rpm portion to them and it is not uncommon for one or the other to go out? Also put new plugs in and verified both are firing by taking them off one at a time. What do you guys think?
If it was just a carb I would expect it to stumble a bit, not advance smoothly to that rpm- likewise if it was a fuel pump issue? This engine sounds great to that rpm exactly every time. I do know it has high speed jet in the carb but it would have to be fully plugged to stop at that exact spot each time?

I do have a shop manual and am going to hook up to a meter to test

 

[Kimbajmann]

Re: 1976 mercury 402 not going over 1800 wot

any thoughts on if I aim thinking this out correctly?

 

[Coloradolakeboy]

Re: 1976 mercury 402 not going over 1800 wot

Test the stator. Check the stator wires. You might get away with putting liquid tape on the wires that have lost their insulation.