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lanier92prostar
06-03-2008, 05:47 PM
Took the boat out for a slalom run this past weekend and it was cutting out or the transmission was slipping in the turns. I checked the trans fluid and it seemed to be a little high because it was on the last dash on the dipstick while cold. Anyone have any ideas? The boat driver thought it was the transmission and possibly not enough fluid. I was skiing when it happened. 92 prostar with the 240 hp engine and original carb. I have never had this problem before.

Monte
06-03-2008, 06:03 PM
Has it done what the driver described again with you driving??

lanier92prostar
06-03-2008, 06:13 PM
Trying tomorrow. You definitely knew something was going on because I boat lost all power in the turn and then took off again out of the turn. I am going to take it out tomorrow and run it and see if it duplicates the problem. Just trying to get some ideas of what to look for. Thanks for the reply.

sdesmond
06-03-2008, 06:18 PM
That honestly sounds like the transmission to me. I had a tranny cooler line bust on me and it did that. It would rev and then catch and take off. It was doing this because it was low on fluid. I replaced the hose and added some fluid and all was well.

Hunterb
06-03-2008, 06:48 PM
Check your tranny fluid again only this time check it IMMEDIATELY after shutting down when it is warm. It should be to the top of the marks. I think if it is slightly below the marks when cold then it is way below when the fluid is circulating through the cooler lines. This will cause exactly what you are experiencing. Many boats are designed with the cooler quite a distance from, and above, the tranny and the lines will drain into the tranny after shutting down for a while (quite quickly actually) which will give you a false high reading if checking when cold.

Run it till it's warm, shut down, check immediately. I will bet you find it low on the stick. It needs to be at the top or it will slip.

Hope that helps

Bruce

sk8salomon
06-03-2008, 09:29 PM
wow, that sucks man! i wonder if the prop or trans gets more load in the turns hence the slippage?

Jim@BAWS
06-03-2008, 09:53 PM
Foward clutches in the transmission

Jim@BAWS

lanier92prostar
06-03-2008, 09:57 PM
Foward clutches in the transmission

Jim@BAWS

Would that only happen in the turns? It ran fine for the first run while I was driving and then it only did it in the turns.

lanier92prostar
06-03-2008, 10:25 PM
Check your tranny fluid again only this time check it IMMEDIATELY after shutting down when it is warm. It should be to the top of the marks. I think if it is slightly below the marks when cold then it is way below when the fluid is circulating through the cooler lines. This will cause exactly what you are experiencing. Many boats are designed with the cooler quite a distance from, and above, the tranny and the lines will drain into the tranny after shutting down for a while (quite quickly actually) which will give you a false high reading if checking when cold.

Run it till it's warm, shut down, check immediately. I will bet you find it low on the stick. It needs to be at the top or it will slip.

Hope that helps

Bruce

Thanks, I will check that out tomorrow when we go out. That makes sense. I will then go to Jims suggestion, but that sounds like it will cost more than a quart of transmission fluid. When I changed it this winter, I used Dexron III, is that what everyone else is using?

Bellinghamster
06-03-2008, 10:43 PM
Your post stated it was "either cutting out or the transmission was slipping"... those are very different symptoms. A significant factor to pay attention to is whether the engine revs higher when the boat slows down, or the engine falters (revs drop).

If the engine revs and the boat slows it's either the tranny slipping or prop cavitation.

If the engine falters I'd look for low fuel float level in the carburator or wiring chafe or a loose connection that shorts out or opens the ignition circuit when g-forces are sideways.

If the tranny is slipping, first make sure when the throttle/gear lever is in forward that the lever on the tranny is fully in forward position (disconnect the cable while in forward and see if the lever on the tranny is in the detent. If it moves farther than the cable pushed/pulled it, then adjust accordingly.. check reverse also)

TCrate
06-04-2008, 05:07 PM
I second the trans slipping. I have a '92 prostar, 1:1. Had same issue in the turns and the fluid was slightly low. I added a little more fluid and issue was gone. Have to check the RPM's when it happens. RPM up when it falters = Transmission, RPM's down means Carb or something else.

lanier92prostar
06-04-2008, 10:56 PM
I second the trans slipping. I have a '92 prostar, 1:1. Had same issue in the turns and the fluid was slightly low. I added a little more fluid and issue was gone. Have to check the RPM's when it happens. RPM up when it falters = Transmission, RPM's down means Carb or something else.

Thanks for all the advice. I ran the boat tonight until the fluid was warm and checked it. It was significantly low. Added some fluid until I got it full and the boat ran perfectly. Thanks to all.

fintek9
06-04-2008, 11:00 PM
Good to hear that! I hate early season demons.

lanier92prostar
06-04-2008, 11:01 PM
Thanks. Always something with a 16 year old boat.

fintek9
06-04-2008, 11:06 PM
Old boats/newer boats, at least you didn't have to put in a new motor! that was my "demon" this year:o

lanier92prostar
06-04-2008, 11:12 PM
I have prided myself in the past on the upkeep at least mechanially on my boat. I used to have someone service it every year, but I have started to take on this task after joining this forum and seeing how easy general maintenance is. Unfortunately for me the trans fluid was obviously low to start with and had not been changed in a while ( another of the reasons I started to do the maintenance myself) Live and learn, at least I didn't do any damage that I am aware of. Best of luck with your boat this summer.

fintek9
06-04-2008, 11:15 PM
Right back at ya! Let the fun begin!:D

lanier92prostar
06-04-2008, 11:17 PM
Unfortunately, our fun will not last that long. Lake is already down 14 feet and projected to go down another 2 to 8 feet this summer. Going to be a short ski season.

Hunterb
06-04-2008, 11:17 PM
Glad to hear it was just the fluid level. A lot cheaper and easier to fix than if something was messed up inside. Keep your eye on the fluid level as it should not drop at all. If it's losing fluid the most likely culprit is the output shaft seal.

Good luck.

Bruce

Willski
06-04-2008, 11:18 PM
Had a similar situation, but not in turns, only under hard starts, felt like prop cavitation. Checked fluid, was low, added fluid, no problem!!

lanier92prostar
06-04-2008, 11:19 PM
Glad to hear it was just the fluid level. A lot cheaper and easier to fix than if something was messed up inside. Keep your eye on the fluid level as it should not drop at all. If it's losing fluid the most likely culprit is the output shaft seal.

Good luck.

Bruce

Did not lose any fluid, just didn't add enough. Thanks for the advice on how to check the fluid. That was the problem in the first place, I didn't check it correctly before I changed the fluid.

Willski
06-04-2008, 11:19 PM
Glad to hear it was just the fluid level. A lot cheaper and easier to fix than if something was messed up inside. Keep your eye on the fluid level as it should not drop at all. If it's losing fluid the most likely culprit is the output shaft seal.

Good luck.

Bruce

Would that leak into the water, because I don't think I lost fluid into the bilge.

Hunterb
06-04-2008, 11:25 PM
My experience, which is not that extensive, is that it is very difficult to get the props on these boats to cavitate. Every time I've seen one of these boats lose power while the engine revs up it has been the transmission and every time it's been low fluid. Usually it's in a tight turn under load when I assume there is significantly increased load on the prop combined with the potential for fluid to 'slosh' to one side of the tranny causing it to mementarily suck up air.

Ooop. Just saw your question. It will leak into the bilge if it's leaking.

Good luck with the boat

Bruce