I recently purchased a long tail, it's a go devil frame with a kohler 20hp command. It was " homemade" if you will. I am having a problem with it that I just can't understand due to lack of go devil knowledge. The first time I ran it, it did ok. Then the next time I was in shallow water and it was like the prop is stripped. It will stop spinning when in a bind. The motor tachs up like normal but the prop isn't moving. If I lift the prop out the water it will spin flawless. If I am deep water it runs fine also. In shallow water if I go slow I find it doesn't act up or as bad. Anyone can help me with this?

Most likely the shaft is slipping in the yoke. On the engine end. My godevil did the same-the key fell out of the shaft.

Ok thank you, I will check that. Would the prop being loose have any affect on that also. I noticed I can turn the prop with out the shaft turning. I can make about half a revolution. The top blade can spin all the way to the bottom maybe a lil more before it binds or moves the shaft

I checked the yolk and the key is still in , it's not slipping on either side. Would it be possible for the prop to cavatate in the mud

Could be the prop isnt biting in the mud... However it should still be spining? Is the prop just stationary in the mud or is there obvious movement at the prop? You are prolly looking at the least getting a new prop, But things arent adding up, If you put power to the prop and it doesnt spin there is an issue with the power transmission (as mentioned above with the slip in the yoke) What would help is to take some photos of the prop, yoke u-joint area, and the frame overall... We might notice something that You could be over looking...

I checked the prop, took it off and everything seemed fine. Found out today this used to be a 9hp go devil and the guy I bought it from must have upgraded it to a 20hp. It's rigged for sure. Motor doesn't fit flat on the mountin plate, I think it's welded to the mounting plate because it's to big. But anyway, I took pic of the prop for now. Need to take pic of the rest of it for y'all

Yep the upgrade deal makes sense... How much of a gap is between the the shaft housing there and the prop? Is the prop just butted up against the end of the threads? Is the lower end sealed up and running a bronze bushing? Id pull the prop off, measure it (widest distance between the ends of each blade), report back... It should be running a 9x4 or possibly a 9x5, meaning the prop should be 9" across... Anything shorter than 8.5" you're looking at a new prop which is more likely... I ask about the distance between the prop and the shaft housing thinking it might be binding up but thats unlikely if it does alright in deep water... Like you said get some more photos of the whole rig and some photos of the shaft with the prop pulled and possibly the end cap of the shaft housing both on and off... Just trying to run though all the possibilities to help a brother out and get ya back on the water...

There should be 2 keys in the yoke. 1 on the engine shaft and one on the upper end of the prop shaft. The prop should turn loosely on the shaft but only a quarter turn not as far as you said it does now. That needs to be tightened some. Need a new prop? Maybe but that prop should run. Fix your problem before you invest money on a new prop-cause a new prop ain't your answer. The shaft will break before you strip a prop. Still sounds like you have a key missing and or possibly a worn out and loose yoke.

I went to go devil yesterday and got a new nut set for the prop, it came with a forward jam but, rear jam nut, brass washers, lock washer, and nylon lock nut. Problem is since this is a custom job I didn't have enough shaft to put both jam nuts. So I put all the brass washers and everything but the rear jam nut. I found out I can get my prop repitched if I bring it to go devil they will do it while I wait, so gonna look into that also. Bring it down to a 9x4 instead of 9x6. More pics to come, only have a few minutes to take pics before going to work. Working shift work has it pluses and minuses

There is two keys in the yoke, as of now both are in it but doesn't feel like it's loose. I will take the set screws out and see about taking the yoke off for better inspection and replace with all new bolts. I did adjust the front of the cavatation plate and bent the front tabs down some. Was told it helps with motor from coming up. Maybe that is making the prop cavatate in the mud where I can't see anything happening but the prop may actually be moving. That is the only thing I done to the go devil since I owned it. I learned my lesson, they run good on the trailer but it's totally different in the mud and water

If the motor is coming out of the water you need to bend the trailing edge of your cav plate up not down.

Take a screw driver or metal scribe and scratch a line on the yoke down into the shaft-do it on the engine shaft and the prop shaft. Then go ruin the snot out of it in the mud and grass somewhere. After that-if the lines don't match up-the yoke is slipping. If they match-then you got another problem.

That's a damn good idea, gonna check that out this weekend!