90tlra

[Bntheir13]

Trying to figure out what is wrong....will start and run great for about 3 minutes...then drops to 2000rmps or so...no horns...coils, and plugs and wires check...seems to be #2 cylinder shuts down...fuel pump assymbly checks...thermostat checks...if you pump bulb with screw out of side of #2 carborator fuel spills thru so not clogged I don't think...if you let it sit for 30 minutes or so...will go thru same routine...start and run fine for 3 minutes or so? I have been told it could be trigger relay or stator...have ohm meeter...not sure how to check though....any other ideas? Have also been told the cdi unit assymblies don't hardly ever go bad on these...any help greatly appreciated...

ps compressions checks also...thanks

[hewesbayfisher90hp]

Sounds like

What year was this?
Sounds like the CDI - it controls #2 cyclinder, the pulsar coil controls cylinders 1 and 3.
Now - when it stops, do you lose the spark to the #2 cyc...figure this out and you can split the problem in half - whether a fuel or electrical issue, but to me right now sounds like electrical.

[99yam40]

measuring the inputs and outputs of the CDI while problem is happening will tell you if the CDI is the problem. All you need is the Yamaha service manual and the proper meter

[Bntheir13]

Thanks so much...have downloaded the manual...just have to figure out how to measure the in and out of cdi unit....as to the year of the motor, unless I'm reading it wrong the A says 2002....do not believe their is fire on number 2 when it breaks down...only basing it on no change when pull plug wire and place against engine...guess I need to get a light to tell me about the spark...Thanks