checking float level with hoses

[rev79xs11]

I like the idea I saw in he tech section about using the clear hoses to see the fuel level. My only question is what is considered proper level? I know it is all about consistency but generally speaking, what reference point can you use to keep from being too lean/rich?

[John]

The 81 is only model that I know of that the floats are set that way, but it does seem like a good way to get them all even. The measurement for the 81 is 3mm plus or minus 1mm from the top of the bowl. The clymers manual states that the bike must be perfectly level, and you should check the float height while the engine is running to let the fuel level stabilize. OR you can set them to the spec for a 79 which is 25.7mm plus or minus 1mmIf they have the correct brass floats in them. If they are 80 carbs, with plastic floats, then the level is 23mm plus or minus .5mm

[Ken Talbot]

Having tried it that way, I would personally recommend sicking with measuring them upside down with the bowls off with a caliper. The hose method will tell you at a glance if the level is way off in one carb, but you then still need to work with a caliper to get that float balanced to one that is good.

The problem I had with the hose method is that it is pretty hard to get even to +/- 1mm balance. With a caliper, you should easily be able get all the floats to within 0.2mm of each other. That is probably overkill, but if you're in there adjusting them anyways, you might as well get them really close.

[TADracer]

I must agree with Ken.

I found that as little as a milimeter off can lead to a rich or lean condition. I did not have any measuring tools handy so I made a set of them from thin stainless steel with some snips, a small file and a machinist ruler that I borrowed from a friend. I made a set of tags that measure from the gasket base to the bottom of the float in half MM increments from 24 to 27MM.

Then over a period of time I tried them all. I took great care to measure each side of the float so that I was assured they were the same level. I found the sweet spot, for my particular bike is 26MM (very close to the stock recommendation).