Float height

Hudders · Post by **Hudders** » Fri Jun 20, 2014 12:20 am

Having trouble setting the float height on my carbs. I've bought 4 x carb repair kits and I've practised on the spare set of carbs but I'm having trouble knowing when the float is in the correct position. Also struggled to adjust the heights as I'm not too sure which way to bend the metal tab.

Does anyone know of somewhere I can take then to be done? I've even whipped out the brand new toobs that I'd fitted in the old carbs so I can get them fitted into the new ones.

Thanks guys

Post by **nugget** » Fri Jun 20, 2014 9:54 am

It's a pity you live down in deepest darkest Essex Steve. It's bit to far to travel from Yorkshire, Mansfield near Nottingham was a fair old trek to stigs.

If you watch this video a couple of times it may help you.

All you do is lean the carbs forward a little so the floats rock forward then slowly tilt them back so the floats are gently resting on the float valve spring. Then get your credit card and take the 14mm measurement from the highest float. Looking at the video it's the one on the right. As you're doing it it will be the one on the left. It's a lot harder trying to write it all down than it is doing it!! If it's to high or to low take out the pin that holds the floats in and gently and I mean gently bend the tang. You'll find out if your going the wrong way with the tang when you measure the 14mm gap again. Good luck mate. It is easy really

wonkiwheel · Post by **wonkiwheel** » Fri Jun 20, 2014 9:50 pm

Is the 14mm gap the same on the thunderace?? The specs say fuel level should 4.1-5.1mm not sure is float height and fuel level are different things??

Post by **Stig** » Fri Jun 20, 2014 10:41 pm

wonkiwheel wrote:Is the 14mm gap the same on the thunderace?? The specs say fuel level should 4.1-5.1mm not sure is float height and fuel level are different things??

different things

float height is the hight of the float when the carbs are stripped, inverted and the measurement taken from the mating surface to thw top of the float

Fuel level is the level of the petrol in the float bowl when measured against a specified point with the carbs assembled and in situ on the machine

wonkiwheel · Post by **wonkiwheel** » Fri Jun 20, 2014 10:51 pm

Ah i see thanks, so will the 14mm credit card measuring impliment thingy be the same for the ace??

Post by **creedxup** » Sat Jun 21, 2014 3:56 pm

The Ace is a different shape carb with a different float height, not sure what it would be though.

MMUK · Post by **MMUK** » Sat Jun 21, 2014 6:14 pm

creedxup wrote:The Ace is a different shape carb with a different float height, not sure what it would be though.

There is no defined measurement for float height. For some reason Yamaha decreed that they should be set wet

However, I did have mine set to 16.5mm dry if that helps? I no longer have standard carbs since my overbore but I made a point of writing all settings down when I was tuning up from standard.

wonkiwheel · Post by **wonkiwheel** » Sun Jun 22, 2014 12:32 pm

Thanks, I'll measure first then make adjustments if necessary, it is running lean even though my mixture screws are out at 5 turns, no air leaks as I can find so check float heights then maybe larger pilot jets.