Power problems? ? 4-tec sportster

[vailboat]

Well I finally got to take my new 03 sportster out for a test run,and discovered that with 2 people in it,it did quite well. It got up and planed on the water ,however with 3 or 4 people it bogged and would not get up and plane on the water. Cavitation or trimming possibly I don't know any suggestions

 

[deadlokd]

Well I finally got to take my new 03 sportster out for a test run,and discovered that with 2 people in it,it did quite well. It got up and planed on the water ,however with 3 or 4 people it bogged and would not get up and plane on the water. Cavitation or trimming possibly I don't know any suggestions

Not sure. But more people more weight I've had 4 people in my utopia 205 and it still stood up. 310hp

 

[vailboat]

Nice boat!! I have the 4 tec 155 but still don't believe it's just power. Going to gap jet drive.boggs out at full throttle with 4 people. But will get up and go with 2???idk

 

[deadlokd]

Dude I have full throttled this boat on 2 occasions. And it IS A BEAST!!!!

It's the lambo of pwc's.

I also have 2-155hp 4 tec rotax engines

 

[deadlokd]

Nice boat!! I have the 4 tec 155 but still don't believe it's just power. Going to gap jet drive.boggs out at full throttle with 4 people. But will get up and go with 2???idk

The paint isn't really paint its rubber[emoji12]. It can peel right off and you can change the colors anytime. $6 can of plastidip. Easy job. Great finish. Done myself.

 

[deadlokd]

Going to finish the other side. Maybe this weekend.

 

[deadlokd]

Also added glow in the dark paint on the chrome and ladder. But thinking about adding LEDS

 

[devonte007]

clarification, you said the boat 'bogs' - what do you mean?

Does the engine reach full rpm and bounce off the rev limiter when you gun the throttles?

If yes, then you are experiencing cavitation in the drive system. could be something as simple as needing a new wear ring or impeller. I would also take a look at your carbon seal and rubber bellows which could leak air and cause cavitation.

First step is to pull the jet pump and investigate. Check gap between impeller and wear ring. Then turn your attention to the carbon ring seal, if it does not look brand new I would probably replace all that stuff as well. If you are able to do the work yourself it is not too costly.

 

[vailboat]

Yes yes it does reach full rpm, and then starts boucings all over!!! However only when I have full load in boat. Runs great with me and the wife.... I appreciate the help and intelligent advice...I only hope I can accomplish the task of rebuilding the pump....gonna try

 

[devonte007]

Sounds like classic cavitation to me. If you are new to these boats, do yourself a favor and download a copy of the repair manual and do some studying. there is also a fellow member who has a youtube channel with lots of great videos working on these 4tecs. https://www.youtube.com/user/3ftDeepChannel

With any luck you will not have to rebuild the entire jet pump, but no way to tell until you start taking things apart. Post back if you have any questions, we're here to help.

 

[Coastiejoe]

I agree. Cavitation. It is most likely a pump related issue. If the gap is more than a width of a dime then replace the wear ring.

 

[vailboat]

Thanks we'll do