just my 2 cent's i have worked on cars for over 25 years and have raced them for almost as long. float levels make a big difrence in performance across the hole power curve givit a try befor you knock it you might just be suprised at the results besides what do you got to lose but time
shane

 

Trust me you are going to have to set those floats some time.

Lots of raptor guys complain about the bike flooding when you pop a wheelie or go up very steep hills. Again, it's caused by the floats being too high.

Might as well save yourself the effort and the shame for not being able to reach the top of the hill and do the floats now.

And hell, you can see for yourself if I am telling the truth about gaining a few HP by setting it right.

 

So in YOUR opinion, are the floats not set to the recommended Yamaha settings, or are the recommended Yamaha settings not good for efficient use of the fuel??

 

you sould have got a raptor

 

The FMF is a low end pipe, you are going to get beat with it.

 

The floats are not set as per the Yamaha service manual. There is actually a problem with the Yamaha Service manual. They recommend running the float level at 3mm BELOW the mating surface. It is impossible, to get it there. The floats cannot open at that level. So, with experimenting I found that they probably meant 3mm ABOVE the split. It seems to work very well at that level, so I always use 3mm above the split for my setups.

A stock raptors float level is set by the factory to be around 6 to 7mm above the split. It is way to rich and causes performance problems. As mentioned you will also find that the carb constantly leak when you tilt the bike just slightly, plus going up very steep hills, some of them stutter and flood.

If you want to get technical and believe the manuals recommendation of 3mm below the mating surface, then the floats come from the factory 9mm out of spec.

The DS, Predator and LTZ400 uses the same make carb, just slightly larger. All their float settings are around 2 to 4 mm above the split. I did not base this recommendation on a thumb suck. I did lots of testing, plus checking other similar models carbs specs to get to the 3mm recommendation.

Try setting the DS carb float level to 6mm above the split and let’s see how well it runs.

 

Above what split?
Below what split?
What mating surfaces are you talking about??

Are you talking about 3mm above the mating surface where the bowl meets the carb body??
Are you using your measurement based on the carb being turned upside down I presume??
Otherwise 3mm above the mating surface would make you even richer (more fuel in the bowl), unless you are making your measurements with the carb turned upside down. [img]i/expressions/face-icon-small-confused.gif[/img]

Got any pics of what you are talking about??

 

The mating surface or split I talk about is the place where the float bowl connects to the carb. I use a clear tube attached to the drain plug of the float bowl to check the level of the fuel inside the carb. For this you need the fuel delivery open as well as open the drain screw at the bottom of the float. The carbs are on the quad as normal and you can do this test without removing anything from the bike. It takes about 3 minutes to do the checking.

 

I see. Thanks for the clarification.
When you say drain screw at the bottom of the "float"? are you talking about the drain plug in the bottom of the bowl or something else??

Got pics??
That would help to answer a lot of questions! [img]i/expressions/face-icon-small-wink.gif[/img]