New boat to me, sport jet 90 baja lacking power

dboard7

Recruit
Joined
Jun 9, 2014
Messages
3
HI,

Im new to this forum and boating in general i just purchased my first jet boat, it is a 94 baja blast with the 90hp motor. it is fun and a blast to ride the previous owner just have all the carbs re-done and it runs great. I took it out yesterday for the first time with another person and it would not get on plane, he had to go to the front of the boat so we could get it up then once were going it was fine until we turned or slowed down and got off plane again lol. The person i bought it from said he would recommend a new wear ring to give it more right off the ba he hadn™t changed it on 2+ years. I have no idea what this is he said it was an easy fix but i can™t seem to find the correct parts could someone point me in the right direction? and also some advice on more info to get this thing on plane and going better?
 
Last edited:

BlueFishCrisis

Petty Officer 3rd Class
Joined
Sep 7, 2010
Messages
96
The wear ring is the part in the jet pump that the impeller rides in. If the clearance gets to be too large, you will lose thrust. It looks like they are available new from Mercury marine part 820243, but you will want to check with your local dealer. Cost is around $300 - $400....... You should also check your compression on the motor to be sure it is healthy.
 

dboard7

Recruit
Joined
Jun 9, 2014
Messages
3
Thanks for the response! im going to take it out this weekend and get the little bit of old gas blown out of the system too and new plugs first and see. the impeller is dinged up so im assuming the clearance on the wear ring is out of wack too and should replace them both. Anyone know how difficult of a job this is?
 

sjbs

Seaman
Joined
Dec 22, 2011
Messages
69
The impeller is stainless and does not wear much.Clean up the edges with a file.The wear ring is aluminum and can be built up with JB-Weld.Do a search for JB-weld and wear ring.
 

dboard7

Recruit
Joined
Jun 9, 2014
Messages
3
Cool that definatly souns like a much better deal to me! ill take a look at it online i'm not the best at custom work but im sure someone can lend a had for a case of beer lol
 

dsrace

Seaman Apprentice
Joined
Jul 13, 2013
Messages
33
this also happens when all three cyl aren't firing. check the vent tubes on the side of the carbs that connect all three carbs to the air box to make sure they aren't plugged and maybe rebuild the fuel pump. also check the fuel tank vent line to make sure it's isn't mostly plugged and not venting properly. make sure the line does not have a hoop up and down like pea trap under a sink. if it is clogged it will starve fuel to the carbs and bogg down like that as well.
 
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