2000 GTI is difficult to start in water

[Schindog]

My recently purchased 2000 GTI will start right up out on trailer but it in the water its takes a while for it to start and after i get it to start it won't idle. I can get it running if throttle it at the right time when starting but it will not idle in water no matter how long I run it. Also for the first 5 minutes I can get it to go top speed but after that it's very sluggish. All this happens every time. Does anyone have an idea of what the issue could be? I saw a YouTube video of someone that changed the rotary valve between the carburetor and the engine and it fixed the same issue. Could this be a possibility? I would definitely appreciate any help. thank you!

 

[POPPS]

Sounds fuel related,,,selector,,or carbs,,,if the RV timing was off, it would be difficult to start

 

[Schindog]

Would that make it start right up on trailer but difficult to start in water?

 

[POPPS]

The load on the prop,,rotating with the crank rotating with the starter
trying to move a 600 pound jetski forward..when you are trying to start it..
There is an old saying,,,champ on the trailor,,,chump in the water!