Sportjet90 electrical issue

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,057
You do a compression test?
The hard start: low comp? The primer not working?

You said:
1 when i put throttle in N the engine rpms dont go back all the way to idle but remain a bit over
Are you in the water when this happens?
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
Look up link and sync and do that.
If the idle is high make sure that the throttle cable is slightly pushing against the tower arm against the idle stop after the link and sync.
If the throttle plates are not completely closed at idle then the motor will hard start especially if it is a late model with the fuel enrichment valve.
Idle should be around 1100 rpm in the water to insure enough water from the jet for cooling.
I think that a link ans sync could fix your hard starting cold issue.
Adjust the idle with the throttle cable off the arm and then adjust it (the throttle cable) for the slight pressure and you should be good to go.
 

Steve1986

Cadet
Joined
Sep 19, 2018
Messages
13
Thanks thats what i was suspecting because i took off the carbs to rebuild them they were all clogged and filthy and since then i have the idle and start issue my mistake somewhere ill readjust. Compression #1-135 #2-130 #3-130 i believe its good a bit lower than what the manual calls for but its not a brand new motor.
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
Your compression gauge could be out of calibration especially if they happen to be Harbor Freight etc.
The relative compression numbers are in line with #1 higher than the other two.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,057
5# isn't anything I'd worry about.
The 90's comp should be al the same.
The myth that the bolder the motor the lower the comp is just that a myth.
My 1988 85's both had thousands of hrs. and both had 145# on all 6cyl.
They had that when they were new.

Low comp on a motor when all cyl read low is usually the gauge.
One cyl low shows a problem beginning.

The later model 120's
The did make them with different values.
The top and bottom were 10# different than the other 2.

Low comp can sometimes be fixed with a de-carb.
Mercury's Power Tune or OMC's Engine Tuner does a good job.
I did a decarb every year.
Back in 88/9 the oil we were sold had stuff in there that was corboning the rings real bad
and they would clog the rings real fast.
I had to re-ring before the motors were a year old.
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
I was wrong about #1 being higher as it is usually lower (CRS strikes again).
From the 93 to 94 Sport jet manual.
 

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