Mercury 90HP Optimax problems

[vanderkool]

Last December I purchased a new Cypres Cay 20 foot pontoon with a 90 HP Mercury Optimax. The manual that came with the new optimax said the first hour change the rpm every two minutes. Then the next three hours run the RPM's between 3000 and 4500 changing every 10 minutes.

Once this was completed and at 10.5 hours on the motor, the motor gave up 400 RPM of operating engine speed at WOT. Dealer suggested 10 hours break-in period, but the manual said only four (the above mentioned).

Can anyone advise to where the manual says ten hours, because I did not see it anywhere?? What should I expect? Will I get the 400 RPM's back?

Update: Dealer claims that the 90 HP Optimax manual's break-in period definition is a misprint. I thought this was quite interesting seeing that the dealer claims that the outboard has not been properly broke-in after 65 hours of operation. Any advice??

 

[vanderkool]

Re: Mercury 90HP Optimax problems

Last December I purchased a new Cypres Cay 20 foot pontoon with a 90 HP Mercury Optimax. The manual that came with the new optimax said the first hour change the rpm every two minutes. Then the next three hours run the RPM's between 3000 and 4500 changing every 10 minutes.

Once this was completed and at 10.5 hours on the motor, the motor gave up 400 RPM of operating engine speed at WOT. Dealer suggested 10 hours break-in period, but the manual said only four (the above mentioned).

Can anyone advise to where the manual says ten hours, because I did not see it anywhere?? What should I expect? Will I get the 400 RPM's back?

Update: Dealer claims that the 90 HP Optimax manual's break-in period definition is a misprint. I thought this was quite interesting seeing that the dealer claims that the outboard has not been properly broke-in after 65 hours of operation. Any advice??

It's a cinch by the inch and hard by the yard

 

[steelespike]

Re: Mercury 90HP Optimax problems

I think I would talk to Mercury. I don't know whats up with the dealer
But 65 hours breakin is surely more than enough.Rpm loss could be as simple as throttle adjustment.

 

[robert graham]

Re: Mercury 90HP Optimax problems

Break-in is more common sense than brain surgery, just cruise around the lake, up and down throttle for the first 10 to 20 hours, then wide open for a bit, then back off for a while. A premix motor should run a heavy(X2) oil mix for first few tanks, an oil injected motor maybe add some oil(pint/10 gal.) to first few tanks to help with lubrication during break-in. Change oil in foot after first 10 hours or so since bearings and gears are also breaking in down there. Add a fuel/water seperator. You'll be in great shape!

 

[robert graham]

Re: Mercury 90HP Optimax problems

Regarding your 400RPM's, have you tried adjusting the trim?...that should be good for about 400RPM's, more or less. Good Luck!

 

[vanderkool]

Re: Mercury 90HP Optimax problems

Thank you for your advice. It's greatly appreciated. I had the Cypress Cay on the lake this past weekend. WOT was 5200 rpm. The listed WOT is 5850rpm according to the dealer. I will be taking the pontoon back to the dealer before long and while the warranty is still applicable and insist on a fix.

Thanks again to everyone who replied and offered solutions and advice.

Best regards,

Wayne (Vanderkool)