4 tech revs but doesnt go fast

[motoxfreak]

2002 4 tec. Here is the problem. A few rides back it started doing this. I will give it throttle, and the boat revs but does not move very quick. If I feathered the throttle it would finally hook up and go. After i got it to hook up that one time, it would run fine the rest of the day. Then yesterday I was pulling a tube all day and then we changed riders on the tube and it would not get going at all. I disconnected the tube and feathered the throttle and got it working again. It still seems to struggle and over rev sometimes. I am hoping it is some kind of cavitation problem or possibly the wear ring, but is there a clutch system between the engine and the impellar? Help please.
tom

 

[Dennis]

There is no clutch system....it's direct drive. Look for debris around the driveshaft. If OK then it's probably your impeller wear ring. Don't keep riding the ski if it's cavitating badly. The cavitation will also cause your exhaust system to run hotter than normal.

DAWG

 

[motoxfreak]

thanks for quick reply

Does it overheat the 4 tec even though the cooling is from closed loop water cooling system and a heat transfer plate? Do you know if the wear ring change out is an expensive endeavor

 

[Dennis]

The cavitation will not effect engine temp because the engine has its own closed loop cooling system (as you stated). Your exhaust system is not cooled by this closed loop system. It relies on outside water from the jet pump for cooling. When you're cavitating you are pumping air bubbles into the exhaust cooling system which can cause overheating.
I don't know how much the repair will cost. I'm thinking about $250.00 to $350.00 if a dealer does it. Make sure you ask for a estimate and make sure they know that you want your old parts back.

Good luck, DAWG

 

[seanmay27]

I am having trouble with my 2003 GTX 4-TEC SC . I cant pull someone up wakeboarding but I have more than enough hp. Generally it doesn't get up fast enough to pull me out but without someone on the back I can go full speed. Sometimes the high engine temperature light comes on. There is no debris stuck. Any suggestions?

 

[LouDoo]

Wear Ring

The first thing I would do is inspect the wear ring.

Lou

 

[seanmay27]

Would that be the impeller wear ring?

 

[LouDoo]

Yes, I'm not up to date on the newer models, the older models only have one wear ring.

 

[motoxfreak]

It just gets stranger all the time. Yesterday ran a full tank of gas and pulled a tube with two persons on it and not a bit of trouble the whole day. This has got me so confused. I guess I will wait till he does it more consistently and take it in to be looked at.

 

[seanmay27]

Having some troubles again. I replace the wear ring last week. It was working fine for a bit but now running into problems. Its not performing to top speed and has troubles getting there. There is nothing stuck in the intake grate. When I bring a rider with me I dont get over 10 mph and the high engine temp light comes on.

Any suggestions?

 

[jwalts27]

I would inspect the supercharger. pull the intake hose off and spin the impeller. if it spins freely then it needs to be rebuilt. i am gonna guess that it has the ceramic washers installed still which fail abruptly. search the forum for threads regarding the s/c problems/rebuild. There are tons of threads and usually have the same symptons as yours.

 

[seanmay27]

Could it be the impeller. When I replaced the wear ring the impeller was all dented and damaged. Could that be causing the problem instead of my super charger.

 

[jwalts27]

If you saw visual damage to the impeller then yes its probably the problem. Definatly replace it.

 

[dieselcrank]

2002 gtx

sounds like my same problem. no power, 10mph trying to pull tune but will do 55 with 2 people on just cruising, but the first day I rode it the ski would all the sudden jump from 54-55 to 63-64. Rode it 40 more miles several times,wont get over 54.