Mercury 25 hp idle too high

[clockmaker]

I have a new 2007 Mercury 4 stroke 25 hp EFI that idles too high for trolling. My idle speed in forward gear(gps) is 2.5 mph. Is there a way I can lower the idle on this motor?

[boats.net]

Idle is control by the idle air control valve and ECU, it should idle at 820-880 rpm's in gear.

[smith46]

So is your problem solved or if there is any more problem then do tell us.I hope it gets solved soon.

[Capt' eye]

Mercury 25 hp idle too high

I would like to share my experience with this same make and year.
My 25hp EFI trolled beautifully she would get down to about 1.5 mph. I could not ask for a better motor to continiously limited out on Walleye's day in and night out!
Well that was until last year Open Day! As I was heading out on Lake Erie just before dark that night. Just got outside of the breakwall heading toward Hamburg...boom my girl just died. Cranked her back up and she would run for 20 second and quit. After 5 trys and same old same old. I check to see if my hose was kinked, nothing. I cranked her back up and heading back to the launch extremely diappointed. She allowed me to crawl back at 2 mph and took me over 3 hrs. Dropped her off at the my perferred tech and waited for his call. 3 days later and he thinking the head is warped. Next day he calls and tells me bearing failure in lower unit. Opened her up and he said it looked like he just cleaned off his drill press and had a dust pan full of metal shaving. To make this long story longer.
Merc replaced the LU at no charge under warranty.
But she is not the same. I can't get it below 2.5 now and my shifting sucks!
I took her back and the tech set to factory specs and it still idles high and the shifting clunks in and out of gear. I am very PO'd.
I talk to factory rep and stated what boat.net replied that the RPM's are to high.
My question is did my tech set it to 820-880 in neutral and not in gear, WOULD THAT MAKE A DIFFERENCE?
Q #2 She run great wide open from A to B. but when I start trolling she stalls,I'll get her going again and 15 minutes later she stalls and she fine until. I repeat the A to B.
Q#3 My shifting is worst off than it was and when I take my hand of the shifter she run at the same speed,as if the friction is torqued down and it is not.
I had read their is a secret screw adjustment on the throttle body that is hidden and according to other has made there shifting a lot smoother. Is there any truth to this and where would I locate it!

Before the lower unit went, the motor ran like like a CHAMP...after it performs like a chump.
Any input would be greatly appreciated.