I adjusted the float levels on my raptor this weekend and I need to check some things. According to the Yamaha manual the float level should be 3 to 4 mm below the joint of the carburettor and the float chamber. I tried everything and there is just now way one can get that right. According to some other post most people are running with the fuel level slightly above the join. I eventually got it to 3 mm above the join, but I had to modify the floats. Placing the carb upside down and having the floats resting on the needle valve it should measure 13 mm form the join in the carb and the top of the float. This left me with another problem. You can adjust the float to measure right, but then it will not let in any fuel. It has a damn stopper on the float that prevents it from opening and letting in fuel. Out came the file and I filed the little stopper at a 45% angle. The length is the same as before, but I had to file it at an angle to get it to open wider and let in fuel. Instead of 13 mm I adjusted the floats to be 11 to 12 mm above the join. I did this as a 1st try and will adjust it further if the rest of you also found it works fine.

The bike seems to run better, but it still has some hesitation at 1/2 to full throttle if you open it up. I dropped the clip on the needle to the last position, (5th clip form top) to make sure it runs rich. I need to play with the jetting still.

My raptor is a 2003 model with air box mods and I am running at 4700 feet altitude. Air cleaner and exhaust is stock.

 

So what was the question? LOL [img]i/expressions/face-icon-small-confused.gif[/img] [img]i/expressions/face-icon-small-wink.gif[/img]

It sounds like you did ok for trying to set them that way. It also sounds like you did some searching of old post. I bet you read about "the clear tube method" sometime while looking. That is th way you NEED to do it. You know where your fuel level actually is, not what the float level is. If your fuel is different it can cause the floats to "float" at a different height than in another fuel. Even if your not using a different fuel this is just a far better method of checking the level. Do a search for "clear tube method" with sixsixT as the author and you'll see what I am talking about if you don't already know.

Alot of people have had trouble with the float levels, myself included. You either; 1: get lucky, 2: fight with them for weeks on end, 3: buy a new carb, 4:??????? LOL I went with door #3.[img]i/expressions/face-icon-small-smile.gif[/img]

 

Hi Ward660r. I used the clear tube method as mentioned by sixsixt. The fuel level was at about 6 mm above the split, and after I have adjusted it came down to about 3 mm above the split. The Yamaha manual says that it should be 3 to 4 mm below the split. They also use the clear tube method to test the level. There was no way in hell i could get it below the split. The other way the manual say to adjust the level is by turning the carbs upside down, and check that the top of the float is 13 mm above the split.

The question was and I am sorry for being unclear. Did anyone else also have this problem and what is the best level the floats should be? (clear pipe method) Sixsixt says it should be slightly higher than the split, but how much exactly? The manual seems to be wrong about this point. I also had to modify the floats itself. Not just bend the little metal thingy, but physically file the little "stopper" on the float. Did anyone else also have this problem?

Another thing I was thinking. With the mod I have done on the floats, it should flow fuel way easier. Have anyone else tried this. It might be useful for 686 raptors.

 

I think anywhere from level - 2mm above the split should be good. I was trying for 1mm above, but never could get there.
I think I remember somebody having to file that peice down. I also think some people where having luck bending the tab in a "Z" shape instead of just bending it up....might have been UBETRUN that filed it down.

I'm not quite following you on why it should flow easier. Its only going to flow as much as the diameter of the hole in the seat will allow it to with the float at any given level.

 

With the stock setup and the level set right, the floats barely move. This in turn will prevent the needle valve form moving wide open. With the filed down "stoppers" the floats can move much more and this in turn will help the needle to move further open, flowing more fuel. It is just a though.

 

I think the manual is wrong about adjusting them 3-4mm below the mating surface. I don't think it's possible to get it down that far, it's hard enough to try and get it even. That's why I said in a previous post "even to just above" but like ward said 1 to 2 mm above should work.

BTW I think Hiram was the one that cut down the float drop tab first.