I know you guys can answer this. I have a 2001 660 Raptor,with FMF high flow headers,And Power Core - 4 silencer. I cant find any info on the proper jetting with these mods.help!!!!!!

 

What mods do you have on the air box?

 

None yet,but i was thinking of drilling a few one inch holes in the lid

 

It depends alot on the air box mods but if you trim the flaps out of the snorkle 150/155 mains should be close.

 

Needle settings?????

 

The needle should be on the third middle groove and I would start there. 2 3/4 to 3 turns out on your mixture screws. And you should always check the float level.

 

Hey Sixsixt ....whats the best way to check the float level as mine will cut out on a sharp inclined hill or when doin a long wheely?[img]i/expressions/face-icon-small-confused.gif[/img]

 

This is the best way.

The best thing to do is check it before you take it apart, with a piece of clear tubing. You can get the tubing at a hardware store for 20 cents, 1/8" clear tubing.

Thu September 05, 2002 3:11 AM



The quick & easy way to check float levels is to use a clear tube that fits the dump hole on the bottom of the carbs. You'll need at least one foot of tubing. Don't worry about an exact fit, the tubing can be a little bigger which will cause some of the gas to leak out but gravity is forgiving and is constant! You can get the tubing from your Yamaha dealer for a few bucks. Remove the stock dump hole tubing, put the new tubing on there & then bend up the other end and run it along side of the carb with the open end facing up. Then open the drain screw next to where the tube is connected & the level of gas in the tube should fill up & be level with or slightly above the bottom/top half of the carb's mating surface. If not, you'll need to adjust the float levels. A sign that the float levels are too high is if the stock drain tubes leak gas while your riding, you'll smell it for sure.
I just pop the carbs on the boots and set the tank on the frame and hook up the hose to check it again, you may have to take it back off once or twice to get it perfect. I also measure the amount that it is off and then take it apart, measure the float height and then bend the tab enough to raise or lower the float the amount that it was off. If that makes any sense.

 

I somewhat understand how to check it, but how high should it be, to the top of the bowls??? Also what do I need to change to adjust them. It is overflowing from the drain tubes when I ride. Thanks.

 

From what I understand the level of fuel in the tube should line up with the mating surface of the carbs, where the top and bottom of the carbs are screwed together. Seems pretty simple to me, if the gas in the tube is higher than the mating surface, the floats are too high, if the gas in the tube is lower than the mating surface, the floats are too low. That's how I understand it.