90 Mercury Sport Jet won't move in water

M

medicmike20

Recruit
Joined
May 6, 2004
Messages
3
I have a 90hp sportjet in a 16'1995 Donzi. The motor runs great out of the water, but when it is in the water, I cant get over +/- 10mph. The RPMs won't go up either. The jet is clear of debris. I have checked everything I can think of, but everything seems normal. PLEASE HELP!!!
 
JB

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 90 Mercury Sport Jet won't move in water

First help is moving this to Merc troubles.<br /><br />The engine is not running great out of the water, it just seems that way because there is no load on it.<br /><br />You are probably down a cylinder or two.<br /><br />Good luck.
 
S

schaiss

Seaman
Joined
Apr 13, 2004
Messages
58
Re: 90 Mercury Sport Jet won't move in water

Pull the carberators and clean them. I bet you will find the main jets plugged with varnish. The fuel MUST be treated prior to winterizing the engine for the winter lay up. $12 will get you a can of carb dip at any auto parts store. Metal parts ONLY get dipped (no float needles).<br />With the carbs cleaned out that thing will be screaming!
 
F

Fishin4fun

Seaman
Joined
Mar 3, 2004
Messages
66
Re: 90 Mercury Sport Jet won't move in water

Have you done a compression test yet? What year is your motor?
 
M

medicmike20

Recruit
Joined
May 6, 2004
Messages
3
Re: 90 Mercury Sport Jet won't move in water

I found the problem!!!! I had a coil wire grounding out. I changed the wiring, and it runs great. Thanks to all!!!
 
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