1989 150hp Yamaha limp mode?

[Asainz320]

Hey guys . Today i was really disapinted with my 89 150hp yamaha. I put the boat in the water, started up the engine, everything was working perfectly. The problem started when i tried to get going. I gave it full throtle and it only got 2500 RPM. It would go over 2500 no mater what. When i had it in around 1900-2000 RPM i noticed it would try to get going, like little bursts of energy, but nothing. The only thing i have done to it recently was changing the lower unit oil. I knew i hadn't put enough in cus it got to the top screw but never spilled oil from the top. When i got back i check the oil and it was a bit white, so i know i need to change it and do it right this time. But can that be the problem? I really dont think so, but ohh well. Let me know. Thanks a lot guys.

 

[lasvegaskid]

Re: 1989 150hp Yamaha limp mode?

If your oil has a white look, that is an indication that water is getting in to the gear case. You need to find out, which seal is leaking. I don't think that would stop your power. It's sounds like your starving for fuel. Lets see if Rodbolt will respond to this?

 

[rodbolt]

Re: 1989 150hp Yamaha limp mode?

could be most anything from a stator to dirty carbs to an alarm condition.
start by testing the audible alarm system.
if its working and you did not hear it its most likly going to be fuel.
when was the last time it ran ok ?
low oil,overheat will set it in RPM reduction.

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

Something i forgot to mention was that it didn't have a problem going in reverse. I could rev it up in neutral and in reverse and it would go up to 5500-6000 RPM, the problem was only in the forward position and when it was under presure cus when i took it out of the water it would rev up in forward gear also. I didn't hear any alarms, and the alarm it working fine, i tested it. I dont think its a fuel thing cus i had a friend pump the fuel pump while under way. And the RPM doesn't go over 2500 and stays constantly there no mater how far back you push the throtle, i think its too exact to be some other problems like fuel or carbs. How can i see or test if its getting into LIMP or REDUCED RPM mode.

 

[rodbolt]

Re: 1989 150hp Yamaha limp mode?

by paying attention, however you pretty much told me I am a dofus .
if all you wish is RPM simply throw the prop in the creek.
RPM will be fine then.
that engine has no clue if its in fwd,nutral or reverse.
its not a smart motor.
if your positive the alarms are working then check coil primary voltage at the problem RPM then fix the fuel system.

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

by paying attention, however you pretty much told me I am a dofus .
if all you wish is RPM simply throw the prop in the creek.
RPM will be fine then.
that engine has no clue if its in fwd,nutral or reverse.
its not a smart motor.
if your positive the alarms are working then check coil primary voltage at the problem RPM then fix the fuel system.

By no means or form have i called you a dofus. I just added some aditional information about the problem, and provided a reason for me not to think it was a fuel or carb related problem. Im not saying it is not posible, im just saying i dont think it is.

Is there any way to bypass the oil related electronics to see if that is the source of the problem? and how do i know if it is in fact going to slow mode?

 

[rodbolt]

Re: 1989 150hp Yamaha limp mode?

test the audible/visual alarms.
if they work and are going off then its either overheat or low oil in the engine tank.
if they work and are NOT going off its not an RPM reduction but either a failure of the fuel,likly, or ign system.
dont splatter it,dont bypass stuff that may be trying to save you from yourself, simply trouble shoot and correct the issue before it takes out a piston.

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

Alright. I'll test those out and let you know. Thanks a lot for your help

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

Hey guys. Im sorry i took so long to get back at this issue but i was out of town for a while. Well i got great news, i fixed the problem!

Well it all came to be a dirty and corroded CDI cable connection!!!

I took the boat out and as i was expecting it did the same thing of not going over 2500 RPM. I took the cover off and took off the plug for sparkplug #6. When i turned on the motor and got going i didn't noticed any difference so i was like "OHH, there something wrong there!". When i checked the cable powering that CDI unit i found it was badly corroded. I cleaned it a bit by hand and put it back on. Tried again to get going and it was fixed!!!! lol. I was so happy i was jumping and screaming all by myself in the middle of the lake. This lake is right next to a highway so im sure someone had to see me when i was really excited, they probably were like "Look at that crazy guy in that boat over there" lol. Well i didn't care, i was really happy that my boat was fixed.

Now i only have to clean the connections really good and problem fixed! BAMM!!!

Thanks a lot for your help guys.

 

[rodbolt]

Re: 1989 150hp Yamaha limp mode?

see
a bit of testing,even though not the real approved way, saved ya a few coins.
glad ya got it fixed,now check ALL the other connections on the engine .
if one is bad most likly others are right behind it.
what color are your spark plug caps ?

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

see
a bit of testing,even though not the real approved way, saved ya a few coins.
glad ya got it fixed,now check ALL the other connections on the engine .
if one is bad most likly others are right behind it.
what color are your spark plug caps ?

The other connections are really cleaned, they look brand new. I think that happened because that specific connection was loose.

The sparkplug caps are black. Why do you ask?

 

[rodbolt]

Re: 1989 150hp Yamaha limp mode?

I asked because occasionally we see them with red caps. red caps have a resistor that needs testing occasionally. factory caps were black with a simplr spring clip. occasionally due to RFI noise in the hull electronics they got changed to the red caps. if your oil control module has been replaced in recent history you will have a green wire running to the CDI from the oil control module to a pulser coil terminal,#2, if so then you will have black caps that are rather long and have a resistor in them.

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

I think mine haven't been changed since the cable running to the CDI unit is black with a white stripe.

How come you changed your name?

 

[rodbolt]

Re: 1989 150hp Yamaha limp mode?

name change is due to I am a dofus
actually right now I am in Caracas Venezuela and cant remember my password so I registered as rodbolt1.0 .
spent 5 days in Rio Chico tarpon and snook fishing,9 days on lake Guri peacock and Payara fishing and hopefully this friday heading for camatagua for more peacock. if not then its back to Rio Chico to chase snook.
on the 17th I return to the land of the cold , cause I gotta worky worky .
its possible yours has been changed, a picture would be worth 1000 words.

 

[Asainz320]

Re: 1989 150hp Yamaha limp mode?

name change is due to I am a dofus
actually right now I am in Caracas Venezuela and cant remember my password so I registered as rodbolt1.0 .
spent 5 days in Rio Chico tarpon and snook fishing,9 days on lake Guri peacock and Payara fishing and hopefully this friday heading for camatagua for more peacock. if not then its back to Rio Chico to chase snook.
on the 17th I return to the land of the cold , cause I gotta worky worky .
its possible yours has been changed, a picture would be worth 1000 words.

WOW!! Nice fishing trip lol. I'll try to take a pic and post it.