View Full Version : Yamaha outboard problems
Tom22
07-16-2000, 10:04 AM
I have a 50 hp oil injected ,3 cyl. outboard...... It will not troll down under 1000 rpm, it will stall, also I had it out today and was running wide open, when it suddenly lost power and went down to approx. 2000rpm, if I tried to givwe it more throttle, it would stall...I had to drive back at 5mph,any faster or slower, it would stall...When I got home I pulled the prop and removed some fish line from behind..Could this have been the problem at high speed? I started it up in the drive, and it would still not idle down to under 1000 rpms...Any comments?
Dirty fuel filter?? Carbs need to be rebuilt??
A couple of things you need to check first - this sounds possibly like a low compression situation on 1 cylinder (not unusual for oil-injected outboards with quite a few hours on them to have rings stick, and cause low compression) - make sure that all 3 cylinders are within 10-15 lbs of each other - if compression is good, I would guess that you have a dirty carb or two, or a bad fuel pump diaphragm.
U. C.
07-16-2000, 06:05 PM
dirty carbs...or something loose, in intake system..causing lean condition.
Take it to a dealer.
Ernie
07-17-2000, 07:54 AM
Had similar symptoms with Mariner 40 (4 cyl). Was a fouling plug. I changed the plug, but it happened again quickly. I looked inside the plug cap and the connection was corroded. Changed the plug wires and we were good to go. I use some sealant on the plug caps now.
I have found that a combination of items could contribute. Don't just stop looking when you find one problem.
GregK
07-17-2000, 02:48 PM
All of the things the guys just said. In addition it could also be a reed valve. The symtoms are exactly what happened to me. Good news, it's a $5 part, bad news, the labor bill is going to kill you.
Time to Move
07-19-2000, 01:05 PM
Tom22:
I got a 115TLRW that i couldnt get to idle without stalling. took it to dealer who charged me a $100 to do a "20 hr inspection" and they adjusted it wrong. Spewed oil and fuel all over the water. took it back and they said "oops" and re-adjusted it and its ran fine ever since. Kinda sore about the $100 to turn a screw but at least its fixed.
I bought a service manual to learn to do it myself. part number on manual dont match motor but they insist its the right one. if only Yamaha had a telephone they could have a human answer i might get some help on which specs to use . . .
Glyde Ryder
07-20-2000, 05:54 AM
I am sure you have already done this but check the oil level just in case the low oil alarm has malfunctioned. 2000 RPM limiter when oil low. That is not you idle problem though.
I just bought the same motor used that you have. (50ph Yamaha 1992) When I tried it out the first time it would not idle below 1000rpm. I checked compression in all three cylinders and it good. I changed plugs, but had the same problem. Finally I had the carbrator cleaned and rebuilt and it idles around 600rpms. I hope this helped. I love my Yamaha.