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engine loses power intermittently

M

mk4283

New member
I have a 1999 Nissan 140, while running down the lake the rpms around 4k, we hit a wake and gave us a good bounce all of a sudden the rpms dropped to 3k and that's as high as it goes, it starts and idles fine, any ideas ? I was thinking carb float needle sticking ?
 
ok, linkages all look good, I was told there is an engine warning sytem that has a few safety sensors, that if tripped will limit engine power through the CDI module, any ideas ?
 
Not likely. BUT... See the details on warnings in your owners manual at http://tohatsu.com/tech_info/own_man_pdfs/Toh60C_70C_90A_120A2_140A2.pdf

See p. 61 of the manual.

If the cooling system has failed, and is not pressurized (due to blockage, etc.), you will have an RPM limit of 2800, so that might be the issue. Is water peeing out of the telltale as usual, and is water spraying from the idle port on the back? If not, you may need to have a new water pump kit installed. However, the buzzer should be ON in that case, and you did not mention the buzzer.

A similar situation will happen if the oil level is low, but the oil light should then be flashing... but you did not mention that lamp. You can check for a sensor wire that came off when you jumped the wake.

WOT range is 5200 to 5700 RPM. If the motor was setup correctly to begin with, then if you have the proper pitch propeller and correct trim, you should still be able to go over 5000 RPM with a normal load in the boat.
 
Thx Paul, yes water flow seemed normal, but it did get low on oil once and when I filled it the sensor to the dash indicator has never worked since . I didn't know till I read the manual about the warning system, I checked wiring diagrams and looked like the CDI unit initiates the system from signal from one of the sensors, so if the oil sensor is bad and I electrically disconnect it shouldn't the system still let it run, taking it out this weekend see what I can find.
 
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