float height question...

[airborneXS]

so im about to take my carbs off and rejet them, but before i took them down i wanted to check the fuel floats...all four of them read almost dead even, heres a pic of where they read at using clear tubing...



the tip of the tool is where im talking about...

[airborneXS]

i guess i should have asked a question...my bad i forgot to finish the post...is this within specs? i have searched the web, read the manual, and i am getting some conflicting information...either that or im just not reading it right...

[petejw]

on the later model carbs,
the float height with the tube method
is where the washer sits, where the float bowl
bolt screws into the carb, im not sure if its the
same with the early model carbs tho, if it is
urs mite be a little high.

[SFSPECBIKER79]

float height

i set mine at .25mm on 79 special. i think the specs. are .24mm- .27mm i found that .25 is a good point to start at and it worked for me. thats from the base where the gasket sets to the highest point of floats. each float bulb needs to be measured and adjusted to same across all carbs. i have brass floats. plastic may be different. one member on website has a online manual you can download to see your specs, search for online manual in search box and that member should come up.

[natemoen]

The 79 carbs have no spec for measuring them with tubing on the outside. The only spec that is given is for when measuring from the inside so that is how you must check. The spec is 25.7 +/-1mm.

[DGXSER]

Not sure how you measure with the tube method on the float bowls before 1981. Only the 81 bowls have the appropriate drain setup to allow you to measure the fuel height in the bowl, the screw comes in from the side with a bottom drain opening, so you can attach the tube and work the screw. Not sure how the XJ bowls look though, may be the same.

The others all have that drain bolt on the bottom, for the 80 carbs you could make a fitting on the bolt to attach a tube to, kind of like a bleed screw in a brake cylinder. But for the 78-79 model carbs, like others have stated, there is no specification for what level to achieve.

[conquest87tsi]

Adjusted floats, now problems

Alright, first a little back ground. I have a 79 special that ran great before I started this project. I was a bit paranoid about fuel in the oil so I wanted to replace the float needles. That and the idle was around 1,900.

So I cleaned my carbs and replaced the float needles and seats. I then set all the float heights with my caliper set at 25.7mm. Reinstalled everything to synchronize and it ran quite rough. Synched the carbs and one of the left cylinders appears to be running quite rich. I;m getting a lot of smoke from the left pipe. The plugs are a few months old so I doubt the 20min I ran it like this would show anything. Plus it was hell hot and late, and I wasn't waiting for her to cool to check them tonight.

My question is, could I have misadjusted one of the floats? I mean I set them all at 25.7mm, but two of them weren't even close to that prior to adjustment, and the bike ran awesome before.

[foreda]

Floats

Alright, first a little back ground. I have a 79 special that ran great before I started this project. I was a bit paranoid about fuel in the oil so I wanted to replace the float needles. That and the idle was around 1,900.

So I cleaned my carbs and replaced the float needles and seats. I then set all the float heights with my caliper set at 25.7mm. Reinstalled everything to synchronize and it ran quite rough. Synched the carbs and one of the left cylinders appears to be running quite rich. I;m getting a lot of smoke from the left pipe. The plugs are a few months old so I doubt the 20min I ran it like this would show anything. Plus it was hell hot and late, and I wasn't waiting for her to cool to check them tonight.

My question is, could I have misadjusted one of the floats? I mean I set them all at 25.7mm, but two of them weren't even close to that prior to adjustment, and the bike ran awesome before.

Do you have brass floats and have you checked them for leaks?

[petejw]

have u also synced and readjusted the mixture screws?

[conquest87tsi]

Float

I did not check for leaks in the brass floats. Like I said, It ran great before I adjusted the heights. I syncronized the carbs, but did not adjust the mixture screws yet. I did adjust the #4 misture screw a little, but had no change on the vaccum guage. I'm not sure if I'm missing something on doing the mixture adjustment or not.