Motor stalls out when you let off the throttle. Checked all connections for wires but found nothing. The motor seems to sometimes try to stall and then other times it just quits. Any ideas?

Check the basics , look at the plugs after it stalls. Are they wet , black ? oil soaked? Need more clues the give you any help.

The plugs are not wet and they grey. Ive checked everything im owndering if it could be the ignition box.

How much freeplay do you have at the throttle? You shoudl have only .030" from the lever to throttle block.

Did this just start out of the blue?
Is the engine down on power while crusing?
Compression test?
Did it do that after a long run when you came to a stop?

Grey plugs = problems.

Well we replaced the power valves with the updated ones b/c it had didnt have the ss ones. The dealer said we shouldnt have to change the springs. Then I replaced the right handwarmer and that is all we did besides replace the steering bushings. We have checked all electrical connections and tried unplugging everyhting while it was running to see if we could find the problem. It seems like it is trying to shut off when it is sitting there running. It wont even go like 10ft without trying to stall, it just seems like you are hitting the on/off switch all the time. We unplugged that and that did nothing either. The dealer said to remove the temp sensor and plug the hole and connect the wires together cause he has heard of problems with them but that didnt work either. When you do get it to run by feathering the throttle it seems like it is loaded up. The first time it did it was coming across the lake and it just shut off and it sounded like it locked up but the clutches just werent disengaged when it shut off so it make a loud noise. But itstarted up right after that and has been doing this since.

Grey plugs and quit running across the lake.....possible engine problems. Need to check engine compression and have a look in the cylinders to make sure you didn't take a piston out. Grey usually indicates aluminum that has melted ie ...piston melted. Hopefully not but may be the place to start.
DB

You need to change the ves springs to green/yellow 700 ones at the minimum with the ss valves. Have you checked the throttle freeplay as mentioned? Check the compression, and remove the valves to check for a problem there. Nut backed off and valve broke?

The throttle play is fine. Im gonna do a compression test to day when i get the tester from my buddy. It really sounds like an ignition problem though the way it shuts on and off. It sounds like as if you were turning the switch on and off constantly. But ill check the valves to! thanks

i would definately check compression...even with the trail heads the 440 motors usually end up with to much compression. I doubled up my base gaskets to get it down and its running fine. Before i did that it quit when i was haulin accross the lake. it can "lock up" maybe 2-3 times before it does any real damage to the cylinders. hope this helps