Yamaha 70HP low rpm problems

[Woogie]

My Yam 70HP 2 stroke has a problem with low rpm and wheezes at idle, when I apply throttle from idle the motor shudders instead of a smooth pickup, but at 2500 rpm and above it runs perfectly.
Any suggestions welcome...

[tripleb]

Hello Woogie,

The first thing that I would do is take the carbs off and clean them.

[Ken]

Woogie,
Yeah, the carbs are probably gummed up if the motor has been allowed to sit up for more than three months without being run.
Before you pull the carbs, try a shock treatment with Seafoam - you might get lucky and that would do the trick.
Good luck,
Ken K

[Woogie]

Cheers guys, will strip the carbs as I can't get seafoam in uk

[Ken]

Woogie,
I believe each of the three carbs have both low and high speed jets - back the jets all the way out and squirt a carb cleaner like Berryman's Chemtool into the seats and clean the ends of the needles. This also might do the trick for you short of removing the carbs.
Good luck,
Ken K

[Woogie]

Thanks Ken, I've got the boat up on the slipway today and also noticed the primer bulb is hard and blows back into the tank so I've got a new one. I will try the jets next..
Thanks
Jason