'01 21i Transmission issues??

[Super B]

This past weekend I was out surfing and an hour into the day, my boat felt like it was cavatating (badly, amost felt like it was put in neutral, and the RPMS were spiking) and started losing power. After that point, the boat would accelerate up to about 10 mph normal, and then fall on its face. No power what so ever.

I checked the transmission fluid, and the level was fine, and the fluid did not seem to be burnt.

Any ideas?

[Moki]

Hmmm, is the engine cutting out at 10 mph or does it feel that the transmission is slipping at a certain rpm, but the engine continues to rev?

[Super B]

We were surfing at 14 mph when it starting slipping. Sounded like the typical cavataion.. RPM's increased, but the boat did not increase speed(did that off and on until I stopped the boat). After that happened, I stopped the boat and floored it from a dead stop. It would accelerate up to 10 mph and it would not increase speed or RPM's.


We were surfing and I did have about 1000 lbs on the starboard side. Not sure if the extreme angle of the boat had any hand in making this issue stand out.

[TRD]

what prop are you running? How much gas did you have in the tank?

I'm weighted on the passenger side of the boat and the gas pickup is on the opposite side of the boat. This has given me problems every once and awhile. Then the next time out it will run perfect. Have you seen this?

[Super B]

I'm running the stock 4 blade 13 x 13. Fuel was around 3/4. And I have seen that issue when the fuel level is below 1/4 of a tank. This issue just cropped up from nowhere. The boat was running great for a solid 1.5 hours before it started acting up..

[AdaminMN]

My boat will do that too. I've only noticed it when I'm setup for goofy footers. But it's only for a split second, and I still can run wide open after it's done it.

My buddy's Pre2150 does it also when we really weigh it down.

[TRD]

I just put on a 653 this year. It seems to be hit and miss type thing. I get it sometimes then I don't. I notice when my fuel is low it is worse. What I did last time was let the air out of the fuel manifold. Seemed to help some.

Do either of you put ANY weight up front? I put a brick (155#'s) in the walkway the last time out and now that I think about it the boat ran fine. It may just be one of those good times out but I will keep an eye on it now.

[Super B]

I failed to mention that I also emptied all of the sacs and the boat was still acting like this. I'm thinking that I warped some of the clutches in the velvet drive....

[TRD]

I failed to mention that I also emptied all of the sacs and the boat was still acting like this. I'm thinking that I warped some of the clutches in the velvet drive....

Super, I'm trying to find some info on this. The guys here at work know a bit about this stuff. Most of them are at the track until after Labor day. I will let you know what they say. It would make sense, just never thought about it.

[huntingwiley]

I used to get a lot of cavitation before changing my Prop. I went to an ACME 515. I usually run about 800# on Passanger side with 6 to 10 people. I have not seen this problem. Always make sure I have a full tank of gas. I have an 03 21ir.

[Super B]

Super, I'm trying to find some info on this. The guys here at work know a bit about this stuff. Most of them are at the track until after Labor day. I will let you know what they say. It would make sense, just never thought about it.

Thanks for the help TRD. This weekend I am going to drain and replace the transmission fluid and water test it. The more I think about this, I am betting that the fluid was low, with the boat listing, all the fluid was on one side of the case causing friction.. Thus leading to my issues...

[The friend Ship]

this happened to us at the beginning of the season, and just was thirsty for some transmission fluid. topped it up, and it ran smooth all summer. we keep some extra fluid on the boat now.

[TRD]

That makes sense. I usually don't have problems unless the boat is weighted down. I need to look at mine again then. Thanks

[Super B]

I drained all the fluid out of the transmission, and measured what I took out. I was able to get a little under 1.25 qts.... and from what I can tell, the velvet drive is supposed to hold 2 qts.

[Joeprunc]

Hopefully that is was the issue. I check my fluids every time I head out.