So the stock coils on a CDI motor cut out around 4300 rpms. I adjusted the out of the water rpms to hit 4300 at full throttle. When in the water with my 35GTR with headwork and a Q exhaust my sweet spot with a stock prop is around 3650 rpms. Anything more than that and the prop starts to blow out of the water and I lose speed.
Here's my question. If I still have about half my governor spring left to adjust, can't I adjust the governor spring to hit 4300 rpms at less than half throttle out of the water and when in the water I should have more throttle to get my rpms a little higher? The coils limit the throttle so I'll never hit the rev limiter unless it kicks out of the water. And even it does hit 4300, I still have my springs shimmed so there shouldn't be a problem, correct?
Everything I've read on here says to set the rpms to 4300 out of the water with a CDI. Why? Am I missing something here?

If you're starting to blow out & lose speed at 3600, there's another issue than the govenor. Is the boat really heavy or beat up? How's the prop?
Sounds like you're blowing out right when you should be getting to the sweet spot & gaining.

The boat's an 1850 Uncle J, not real heavy, and the bottom has no hooks or dents. It does this with a light load. The prop is almost brand new, shows no wear, and is a stock GTR prop.

My thinking was that I could turn up the governor and have more throttle to trim the prop down further and get the rpms up deeper in the water.
I currently have the transom bolt in the top hole. I did this because I couldn't get the prop to ride on the surface of the water in the middle hole and give any rooster tail. Maybe I'll try and move it back to the middle hole?

If you want to swing by, I can take a look at it.

Drop it back to the middle hole & see how it does. If you have a reverse plate, you won't get as much of a rooster tail as the guys without it.

I dropped it back in the middle hole and it gets up the rpms a little better. I do have the reverse plate and I put it on before I even had the boat in the water so I had no reference point other than the other mud motors I've had in the past. I also turned the governor set screw to allow full movement of the throttle and that helped also. I don't start getting blow out of the prop until over 4100 and I can have it trimmed down a lot further. Now I just need to get a couple trim tabs welded on the rear of the boat to stop the porpoising once I get high in speed with a light load and I'll be good to go.
The original reason I moved it to the top hole was because I couldn't get my rpms up. I found out the governor was set to around 3700 rpms after I moved the hole. So I moved the hole and adjusted the rpms to get better performance but never tried the middle hole again.
All is well now!
Thanks guys!

Good deal. What speeds at the middle hole now?

With around ~900 lbs in the boat I was getting 25-26 in deep water. Can't really find any shallow water right now with the water being so high. With ~600 lbs in deep water I was getting a solid 27-28 and it started porpoising. With just 200 lbs in deep water I was getting over 29 and it started porpoising something fierce. When I can get that under control I'll be over 30 easily I believe.

Good speeds fer sure.

Glad ya got er figured out

I'll wait a while on the blind. I'm getting my tabs welded on tonight to stop the porpoising so hopefully speed will pick up a little more. I'll look you up for another run in a week or so probably.