225 yamaha rough idle in gear

kona-jack

Cadet
Joined
Aug 15, 2004
Messages
6
I have a 2001 yamaha 225 fuel injected (OX66) 2-stroke that idles great in nuetral (700 RPM), but when I put it in gear it idles rough and the RPM drops to 500. When I bump it up to 800 or 900 everything smooths out again. It runs great at any other RPM. I changed the spark plugs but it did'nt make a difference. I ran some ring free thru the fuel system also. The motor is also getting harder to start when warm. I purchased this motor this past summer from the gentleman that purchased the boat new in 2001. He only put 60 hours on the motor.<br /><br />Tim<br /><br />torr@csam.net
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 225 yamaha rough idle in gear

other than testing the low pressure fuel pumps for leakage and testing the spark plug caps for proper resistance there is not a lot you can do without a manual.<br /> do you notice an abnormal amout of fuel on the water at idle ?
 

bigbrownbuku

Master Chief Petty Officer
Joined
Sep 17, 2004
Messages
885
Re: 225 yamaha rough idle in gear

try disconnecting your shift switch. look where the shift cable end joins under the cowl on the starboard side, you will see a small switch in that area, unplug it and try again.<br /><br />did you get any kind of service history with your 60 hours? at 4 years old there should have been a whole whack of service items checked on that engine.
 

kona-jack

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Joined
Aug 15, 2004
Messages
6
Re: 225 yamaha rough idle in gear

Originally posted by rodbolt:<br /> other than testing the low pressure fuel pumps for leakage and testing the spark plug caps for proper resistance there is not a lot you can do without a manual.<br /> do you notice an abnormal amout of fuel on the water at idle ?
No there is not any fuel leakage.
 

kona-jack

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Joined
Aug 15, 2004
Messages
6
Re: 225 yamaha rough idle in gear

Originally posted by BenC:<br /> try disconnecting your shift switch. look where the shift cable end joins under the cowl on the starboard side, you will see a small switch in that area, unplug it and try again.<br /><br />did you get any kind of service history with your 60 hours? at 4 years old there should have been a whole whack of service items checked on that engine.
I did not get any service history with the boat. Where would I go to find the recommended service interval for this motor.<br /><br />Tim
 

bernieb

Petty Officer 1st Class
Joined
Feb 9, 2003
Messages
209
Re: 225 yamaha rough idle in gear

kona-jack use the search function .....put in vst
 

kona-jack

Cadet
Joined
Aug 15, 2004
Messages
6
Re: 225 yamaha rough idle in gear

Thanks BenC<br /><br />I found that the shift switch is not working properly. I purchased a new switch and it still does not work correctly. The problem is mechanical. The shift linkage slides within a oval shaped groove, this groove is designed to rotate when shifting to forward or reverse. Mine does not rotate when shifting. I looked in a SELOC manual I purchased, but it does not explain how it works. When I close the switch with a screw driver the computer adjust the RPM correctly. Any one know what to check next.<br /><br />Tim
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 225 yamaha rough idle in gear

kona<br /> if the shift switch is acitvated between idle to 850 RPM cyl 2 and 5 do not fire,850-2000 rpm and 2,5 and 6 do not fire. 2000-3000rpm and 2 and 5 do not fire. above 3000 rom it has no affect. normal opereration,cyl 5 does not fire from idle rpm to 2000 cyl 2 does not fire between 850 and 2000 RPM depending on throttle opening. if your shift slide wont rock in and out slightly it may be mechaniacally bound with corrosion.
 
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