Adjusting carbs idle mixture

MrHeadsocket · 22 November 2014, 16:51

Finally got a free day tomorrow which I'm using to hose down the SIB and store it for the winter. I've had a problem since I got my new Yam 30 about 5 weeks back. It dislikes idling if I take the throttle anywhere below the start point on the tiller, it'll just die. It tends to idle ok ish (but still dies) after it's been run at WOT for a bit I've attached pictures of the 3 carbs, but which screw is the idle mixture? I've been told to turn the screws until lightly seated and then back out 1 1/4 + or - 1/8 of a turn. Is this correct?

Davie · 22 November 2014, 17:30

It's the horizontal brass screw with the spring on it. These carbs especially top one will be blocked up with the bits of your recoil rope. Check the brown roller inside the recoil housing when you fit new rope as I bet it has flat spot and not turning. Hth

MrHeadsocket · 22 November 2014, 17:43

I did realise today so will add a new recoil rope to my shopping list! As well as those rollers! Cheers, it would explain not idling (idle jet clogged) as it's only been a problem since I had it as the previous owner removed the carbs and cleaned them completely!

MrHeadsocket · 23 November 2014, 13:14

How do I adjust all 3 carbs at once?

Davie · 23 November 2014, 14:27

The only way this would be possible is a screwdriver in each hand and one in your mouth but why would you want to do that?

MrHeadsocket · 23 November 2014, 14:36

I suppose I'll have to give that a go!

uncle al · 23 November 2014, 16:32

before any adjustments, you have to make sure all the carbs are opening and shutting at the same time. Then adjust your mixtures , I sugjuest one and a half turns out from lightly seated.

m chappelow · 23 November 2014, 20:33

As Al says screw down "lightly seated" often if the screws been tightened or nipped down on its seat to tight it can then mark or cause a ridge on the taper part of the needle which will then cause an all or nothing setting on the mixture.

MrHeadsocket · 24 November 2014, 10:51

Quote:

Originally Posted by Davie

It's the horizontal brass screw with the spring on it. These carbs especially top one will be blocked up with the bits of your recoil rope. Check the brown roller inside the recoil housing when you fit new rope as I bet it has flat spot and not turning. Hth

Surprisingly the roller is turning! I think it's just a very old recoil rope and will be changed this week!