Thread: I am new here so i hope i do ok.

Can anyone help me? I have a year 2000 model challenger jet boat with twin 85hp/718cc engines. I sometime have this anoying problem with cavitation. This problem only happens from time to time. Sometimes when i go to increase rpms the engines go to max revs but the boat does not go anywhere. I have spoken to some people and they have given me different ideas.
1. Sometimes you can suck up a bit of seaweed and that alter the flow of water going through the jets causing it to cavitate.
2. The trim of the boat needs to be adjusted, but the boat does have not any trim control. But having said that, when if does happen the front of the boat is a bit up in the air.
3. The clearance beetween the impellor and the housing of the jet unit is excessive.
The thing is that it only happens once in a while so i will try to give as many clues as possible. It will pull two ski bisciuts ok but it wont pull up a person on two skis. Iwould appreciate any help.
I live Bunbury WA which is two hours south of Perth.
CHEERS

Thanks for that and i will look at that soon as i get a chance. I thought that could be the problem. How much roughly would it be to to get 2 new liners or would it be easier to get someone to do it?