SportJet 90 problem

bastienlaf

Recruit
Joined
Sep 10, 2014
Messages
2
Hi everyone ! I am from Quebec and I am new on the forum looking for advice on my boat repair. Last week I bought a badass Thundercraft Typhoon with a SportJet 90 from a friend. I paid almost nothing for the boat, my friend who really don't have any mechanic skills thought the engine was dead. So i brought the boat home and began working on it. First thing first I hooked up the battery to a charger and let it charge overnight, the day after I tried to fire it up and TADAM!! nothing happened.. So I started looking for a problem which was not a big deal : I bought a new batt. cleaned the wiring connector on the starter, brushed every connectors and looked for broken wires. After a few hours it finally powered up, i got power on the starter, blower, radio.. everywhere, so I filled it up with gaz and took it to the lake, once I got on the lake i fired the engine which was running pretty good on idle, the problem was when I push the throttle lever, the boat start moving but I could not get the boats off the water it was doing maybe 10mph max, I felt the engine was having a bad time revving up. I made myself an adapter to hook it to a garden hose so i can run it out of the water.

Anyone ever face a similar problem? I just wanna know where to start with that engine,

What I know so far:

ENGINE : SportJet 90 S/N: OE100091
Stator: Red
Spark Plugs: Brand new good spark on all of them (not tested with a tester tough)
Fuel filter: Brand new
Oil Injection: Broken (From what I was told by the last owner) and it looks like it's an electric pump (not oem??)

Any advice would be greatly appreciate!! I would love to drive it before it gets too cold (which is pretty soon in my country)
Thanks !
 

sixfigures

Petty Officer 2nd Class
Joined
Nov 4, 2013
Messages
115
do a compression test if the oil pump failed up it may have damaged the rings and pistons, I would use premix and forget the oil injection. but the damage may already be done or the carbs are clogged up, that power head uses carbs with bowls/ floats etc because it is actually an old force outboard engine. one more simple thing, is the fuel old or did it have old fuel in the tank and someone added new fuel. try running from a small fuel tank with new gas and see if that is the issue, old fuel will do exactly what you described.
 
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