2000 90 johnson seapro is it a lemon?

iwilliams

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Oct 13, 2007
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Just purchased. Ran great two times. I filled up w/ 87 octane now after running for 15-20 minutes at 4500rpm motor starts to cut out as if it is starved of fuel. Already replaced h2o seperator and checked filters and checked for sufficient flow to motor. Also tried running w/ auxillary tank and 89 octane and had same results. I am lost now first boat. Did I buy a lemon?
 

1730V

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Feb 14, 2004
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563
Re: 2000 90 johnson seapro is it a lemon?

Did I buy a lemon?

I don't think so. Because it runs so long before it cuts out, it sounds like a heat issue.

Have you serviced the water pump?

When it cuts out, do you lose spark?
 

iwilliams

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Oct 13, 2007
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Re: 2000 90 johnson seapro is it a lemon?

Haven't touched the water pump. When I say it cuts out I mean it is sporatic. Almost like it is sucking air into the line.
 

1730V

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Re: 2000 90 johnson seapro is it a lemon?

Almost like it is sucking air into the line.

It may very well be. Every hose, under the hood needs to be looked at.

I assume the primer bulb does not get sucked flat?

Heat usually effects coils and power packs, it that order. If you are just dropping a cylinder or two, it's probably coils. You can diagnose that with an inductive timing light. Just move the timing light lead around until you find out which coil is misfiring.

Get that water pump serviced or you may melt the whole thing down.
 

iwilliams

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Re: 2000 90 johnson seapro is it a lemon?

I can throttle down (after it starts cutting in and out) to 2000 rpm and it runs fine. Any ideas?
 

1730V

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563
Re: 2000 90 johnson seapro is it a lemon?

That sure sounds like a fuel issue. If you are running it on an inboard fuel tank there is a valve in the outlet of the tank. That valve is called an anti siphon valve. They sometimes sticks. However, you said that you ran it from a portable tank?

That engine is also equipped with the S-L-O-W system. If it detects an overheat or oil restriction, it will slow itself down to avoid self destruction.

I think you need to do some serious maintenance on this engine before you go out running around at WOT.
 

bgbass.1

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Aug 1, 2007
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558
Re: 2000 90 johnson seapro is it a lemon?

question when it starts doing it at wot does rpms jump up and down? I know you said it seems ok at 2000 rpm it is probably overheating had one doing same thing replace impella and themostat should fix problem
 

iwilliams

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Oct 13, 2007
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Re: 2000 90 johnson seapro is it a lemon?

Water seems to be circulating just fine. I did run an auxillary tank through the water separator. Some one else suggested the clogging of the anti siphon valve but when I disconnect the fuel line at the motor and squeeze the bulb flow seems just fine.
 

bgbass.1

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Re: 2000 90 johnson seapro is it a lemon?

when it starts doing it throtle back so its not bucking and touch top of head if you cant hold hand on for a couple seconds its probably gettin to hot. the other thing is to pull a plug wire and see if it changes tone if it does coil
 

iwilliams

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Oct 13, 2007
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Re: 2000 90 johnson seapro is it a lemon?

You just described it exactly. How can it be overhaeting if water is flowing? Thermostat sticking? I believe there are 2. Thanks for the help!
 

bgbass.1

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Re: 2000 90 johnson seapro is it a lemon?

yes thermostat sticking take them out and run it if it cures problem you know what to do.
 

boonmaker

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Aug 8, 2009
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Re: 2000 90 johnson seapro is it a lemon?

I also have the same boat and motor.It runs fine down aroun 27 mph and when I go up to about 35 mph it starts cutting in and out throttle back and runs good.I changed the gas checked the flow new spark plugs and separator.
Do you think its the thermolsates
 
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