Max RPM 3500

[onebadc10]

I just took my 1988 mercury 135 to the repair shop because it would not idle.The shop installed a new stator.
It idles good now but rpms wont go past 3500 when pushing the boat.In nuutral it revs fine.Any Ideas
Thanks
tony

 

[Maxz695]

Re: Max RPM 3500

prop slipping? did someone say MAX? (RPM) Just kidding but prop comes to mind not a pro her may need rebush. No that can,t be it you have full rev if the prop was slipping you would have more than 3500 RPM Check to see you carburetor butterfly is opening all the way

 

[onebadc10]

Re: Max RPM 3500

Even if it was fine before the stator?

 

[Faztbullet]

Re: Max RPM 3500

Take the wires off the rectifier and retest, if it runs fine the rectifier is bad and likely cause of stator failure.

 

[onebadc10]

Re: Max RPM 3500

Will bad Rectifier cause the RPM problem?

 

[onebadc10]

Re: Max RPM 3500

voltage does go to 16volts at wide open throttle.Batteries are new.When you say unhook the rectifier and test do you mean to run the boat with it unhooked and see if rpms are regained?

 

[onebadc10]

Re: Max RPM 3500

Had time to do a little checking.Has two coils not firing.changed them with two other cylinders and the started working.So I guess the boxes are good.
What would cause the two coils to go out at the same time and the are are on different sides controlled by different boxes.They are sierra coils and with only about 10 hours on them.I replaced all 6 last month just to have new ones on the engine.

 

[narvlebenoit]

Re: Max RPM 3500

short. Maybe a wire touching somewear

 

[Maxz695]

Re: Max RPM 3500

sent a link for 3 used coils on eBay in your inbox I think the from a 40 HP 1997. Bid at .99 and 9.50 shipping I think

 

[Faztbullet]

Re: Max RPM 3500

Send them back as they have a limited lifetime warranty, check the grounds to coils and ignition plate...