I have a mercury sportjet 120xr 1997 that was just rebuilt…

When you are at WOT, can you verify with a timing light that all 4 cylinders are still firing?

Also, since you have some run time on them, can you pull the plugs and look at the tips of them to see if one is a different color than the rest?

How would you test the fire at WOT, or read the plugs?

Using a timing light on each of the plug wires. Yes I understand that the engine cover needs to be up to do this and there is not much room in there.

#2 looks a bit whiter than the others.

Were you able to test the spark on the cylinders at WOT?

Can I see the reeds, or are they already installed?

That float setting could do it.

Jet parts are hard to come by for sure.

I need to see it to tell. Where did you get them and what is the part number of them.

What is on the reed plate where that gasket hole is? It is solid?

Ok, the new gaskets are fine. The hole is used on different models with the same plate. One of the part commonalities that Mercury likes to do sometimes. Cam make putting stuff back together a bit tough when you notice things like that.

No I dont think that is part if the running issue.

I would only go out another 1/2 past where Boyeson wanted you to go. The idle adjustment will not effect the top end speed on the engine. Fuel delivery and spark timing do. IS the timing actually getting to WOT spec?

Long as they are clean, they should be ok. When you had the carbs off, did you take them all the way down and totally blow everything out with carb cleaner?

How do the magnets look on the bottom of the flywheel?

If one has moved, that will cause it to not want to open up as well.

Have you measured the voltage that is going to the coils when the engine is up on plane or at WOT?

That is a different set of windings in the stator. At WOT the coils need to be getting 150+ V from the switchbox and stator.

You can check it on AC volts. It will just be jumping very fast.

The valve will warm up as the engine runs. You can test the enrichener by removing it and applying voltage to it. The needle should move out as the thop is heated by the voltage. 12V from a battery will work.