Adjusting Idle speed on Yamaha 904S

Sod Farmer

Cadet
Joined
Jan 15, 2008
Messages
18
Can I (How do I ) adjust the idle speed on my new Yamaha 90 4 stroke? The dealer told me that I couldn't, but I find that hard to believe.
 

StrykeKing

Cadet
Joined
Nov 5, 2007
Messages
19
Re: Adjusting Idle speed on Yamaha 904S

The dealer is correct, although there is a switch for the tiller model which adjusts the rpm up to 150 in 50 rpm increments up or down. It was easily wired into my remote model, just had to lengthen the wiring. Makes it handy when docking, my boat does about 3.5 mph at idle which makes the dock come up real quick.......... Also used it for fine adjustments when trolling, before I got the kicker.
 

Yamajoe

Petty Officer 1st Class
Joined
Oct 31, 2007
Messages
264
Re: Adjusting Idle speed on Yamaha 904S

If your motor is an EFI then correct, the computer controls idle; if it is carbs, then yes you can perform minor adjustments.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Adjusting Idle speed on Yamaha 904S

yep EFI you simply set up correctly and it either idles where its supposed to or its broke.
on lenghtening the tiller troll speed switch,
a quick read through the installation and rigging guides will show a warning in bold letters stating DO NOT lengthen the wires,
I asked why as was told it was shielded to keep RFI from toggling the ECU.
however no one really knew.
but if the manual says no I just dont.
 
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