Question concerning SLOW function in 1994 OMC 140 hP outboard

[lstill]

Hey Guys, have a 1992 22 Proline with a 1994 140 OMC Outboard that I have a question concerning the "SLOW" function incorporated into the powerpac.The boat will crank and run fine and as soon as you run it some and get it into a cruzing mode it cuts thr power back ? it runs good but has limited power and won't plane the boat. I read that overheating can cause this but the motor dosen't seem to be overheating at all? I also read that a no oil situation to the pump can cause this but the guy had eliminated the VRO pump and was pre-mixing. Could the fact that he plugged the oil line and eliminated the oil injection be causing this. Is there a way to bypass the slow function in the power pac just to see if this is my issue? any help appreciated larry

 

[Chris1956]

Re: Question concerning SLOW function in 1994 OMC 140 hP outboard

Lack of oil will not initiate the SLOW function. if the overheat sensors detect overheating (real or not) they can trigger the SLOW system. Start and warm up the motor. Now disconnect both overheat sensors and see if the motor runs better. of course you had better make sure the motor is not overheating.

 

[alumacraftmvtek]

Re: Question concerning SLOW function in 1994 OMC 140 hP outboard

I have a 1993 Johnson 150 I don't know how similar they are but I was having the same problem you are having. It would run fine on muffs and for the first short run on the lake ir was good. Any run longer than 10 minutes my boat would cut back to below 3500 rpm. Turns out I had a thermostat that had cracked went ahead and replaced them both no trouble since then

 

[metriccrescentwrench]

Re: Question concerning SLOW function in 1994 OMC 140 hP outboard

H.... but the motor dosen't seem to be overheating at all?

How do you KNOW that the engine's not overheating? We'd hate to have your next thread be titled "I cooked my motor, now what?". Before you just disconnect the temperature switches to "see what happens" you should invest in a water pressure gauge and temperature gauges, they're not at all expensive and are sold in the iboats store. I'd say that it's pretty unlikely for a temperature switch to give a false indication (though admittedly not impossible). You're asking for big problems if the engine overheats with the temperature switches disconnected.

Oh, by the way..... standard question - when was the last time your water pump was serviced?

 

[boobie]

Re: Question concerning SLOW function in 1994 OMC 140 hP outboard

Does the mtr jerk or just run smooth with no rpm gain. You may be dropping some cyls due to fuel or ign.