Yamaha 150 dead cylinder?

shorebound

Recruit
Joined
May 25, 2008
Messages
3
I'm pasting this from another thread I started in THT http://www.thehulltruth.com/boating-forum/687885-150-yamaha-4-stroke-dead-1-cylinder-fuel-system-part-numbers-inside.html#post8075119.

The issue:
Prior to the electric pump dying it ran great for half an hour and I thought my fuel issue was resolved. So after replacing the pump, I took it out and it ran better at idle but wouldn't get past 2700 rpm. I pulled each injector plug and noticed #1 caused no change. I pulled it out and put carb cleaner in it and put it back in. Picked up 300 RPM. I decided to replace all the filter baskets after that because I'd already gone thru each injector several times at home with the whole syringe/12v cleaning process.


Now, I'm concerned because I have 40psi at the rail in the driveway, good idle and snappy acceleration--- but when I pull the injector plug or spark plug wire for #1 piston, there's no detectable change in the motor. Next steps will be compression test.
Does anyone have any insight why there's no change when I unplug #1?
idle is at 800 rpm and it's pretty smooth. I would think it would be choppier if one piston isn't participating.

Part #s:
Through my search I was able to find that the fuel injection system uses Mitsubishi parts. The fuel pump I was able to purchase on ebay for $18 instead of the 300 or so Yamaha wants.
http://www.ebay.com/itm/EFI-Fuel-Pum...-/231322754465

The injectors are the same as used in the 2004 diamante and are part number CDH275. I found a manufacturer in long beach that sells the injector filter baskets (bosch universal # 1-109) called gb remanufacturing. Very friendly and easy to deal with. I bought new baskets for 27 cents a piece. www.gbreman.com
 

shorebound

Recruit
Joined
May 25, 2008
Messages
3
Checked compression last night. Is good..150 on all and builds very fast.
It starts right up, but farts a few times until idle gets going. Idle is 800RPM & steady. Still no change when I pull injector power on #1 (bottom) cylinder, but pulling any other almost kills motor.
I changed plug wires and plugs. No difference.
I ordered a Yamaha code reader. Not sure what else to test.
 
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