Yamaha 90 2-Stroke Runs Rough @1800 rpm

[Manwohr90]

on a scale of 1-10, easiest to hardest, what is the difficulty in reaching these jets, cleaning, and reassembling?

I change my own water pump, fuel pump, thermostat, etc., without too much trouble.

Will the carbs need to be synced? If so I'm afraid that's something I've never attempted and I doubt I have the correct tools to pull it off.

In a nutshell, should I take it to a Yamaha tech?

[robert graham]

If it was me, I'd find a real certified Yamaha technician and tell him the history of the motor and get his thoughts regarding possible solutions....

[TownsendsFJR1300]

on a scale of 1-10, easiest to hardest, what is the difficulty in reaching these jets, cleaning, and reassembling?

I change my own water pump, fuel pump, thermostat, etc., without too much trouble.

Will the carbs need to be synced? If so I'm afraid that's something I've never attempted and I doubt I have the correct tools to pull it off.

In a nutshell, should I take it to a Yamaha tech?

If you can change out a water pump, you can take the carbs apart, clean, get to the jets etc. Have a shop manual or at the very least, print out the parts fisch of the carb. I'm not sure of your set up re syncing if its just linkages or using a vacumm gauge so I can't comment on that..

I do agree, it may be worth your while to get another opinion. The previous mechainic may not have been up to the task.

[99yam40]

no need for vacuum gauges for those 2 strokes, just mechanical linkage sync