Setting Float Levels

[Freebird]

OK folks...I need some input here. I've seen several discussions on setting the float levels. I'm NOT much good when it comes to carbs. I can sync them and etc. but am always nervous about getting inside them.

 

So yesterday, in my unending search to figure out my gas mileage problem, I decided to pull the carbs and check the float levels and etc. Several of you, including Cougar, Pegscraper and some others have done this and have reported that it's not a big job. WHATEVER...it took me about 10 hours to pull the carbs, set the floats and get it all back together. To make it worse, I'm now thinking that I may have done it wrong and need to pull them off again.

 

The manual says that you set the floats at about .32 with the floats resting on but not compressing the needle valve. So, does that mean that with the carbs upside down that you lift the floats with your finger so that the tang is touching the needle and that is when you measure? Unfortunately, I set them with the carbs upside down and the floats at rest, not me lifting on them. I'm attaching a picture. You will see in the picture that the near side is laying way up in the housing. The far side I have adjusted and it is at about .32 with it just sitting there. I think I did it wrong but please tell me for sure.

 

Here's the deal. Yesterday morning I check all four cylinders using my Colortune. At most all RPMS I had the nice Bunsen blue color as I should but had intermittent flashes of yellow. According to the color tune booklet, that is a sign of floats set too high. That is why I pulled them off.

 

Finally got it all back together last night about 9:00 and fired it up. Now I have a definite backfire, pop, miss or something from the right side. Now I have not synced them yet and will do so but I really don't see where adjusting the floats would through the sync off.

 

So.......HELP.

[Johnh]

The way I was taught, and always have checked float levels, is to hold the carb so the float hangs vertically from it's pivot point, and gently tip the carb so the weight of the float firmly presses the needle into the seat without compressing the spring in the needle. Then measure.

[Squeeze]

Hi Don,

 

i've downloaded the Workshop Manual here from the Library.

 

On Section 6, Page 8 (Page 277 bottom) is the Measurement shown.

[Orrin]

Don, you are a better man than me. I would not even attempt it. But I want to learn.

[Freebird]

Hi Don,

 

i've downloaded the Workshop Manual here from the Library.

 

On Section 6, Page 8 (Page 277 bottom) is the Measurement shown.

 

Yes, I have the manual and that is what I went by. It is not clear to me though if the floats are just resting there are being held up.

 

Anyway, I just finished syncing the carbs and that was the problem. I won't even pretend to understand why the float levels affect the sync but I can assure you that they do. After putting it all back together my sync was WAY off. They are now synced again and it is purring like a kitten. Now I just have to put some miles on it and see if it had any affect on my poor mileage. At least I'm not out there pulling the carbs again right now.

[pegscraper]

It sounds to me like you did it right. Here's a pic of when I did mine, carbs upside down, floats down with the needle resting on the seat.

 

Were all of yours as high as that near one? Were any of them even the same? The float level affects how rich or lean all the rest of the circuits in the carbs run, and when they're not the same that will affect the sync. You'll compensate for it at idle with the sync screws, but then at anything above idle they won't be operating the same. I'm not surprised that if you had to move the float level very much that the carbs would need to be resynced. You'll probably find it running smoother now than it ever has since you've owned it.

 

It'll be interesting to see if this helps your gas mileage. You've said that at one time your gas mileage was good and then got bad, meaning that something changed then. Generally, once floats are set, they don't move much, if at all. They're good for a long, long time. As far off as it looks like yours were, they were never set right from the factory. I found mine the same way.

[Freebird]

Mine were all about the same. Actually, I'm not sure the tang was even touching anything. It appeared that they were going all the way up and resting against the head of the screws that hold the tang in place. I just got back from a short ride and it is really running good. Just have to wait and see on the gas mileage. I'm not optimistic because the gas mileage seemed to have gotten bad all at once, like something really drastic changed. I've checked and changed plugs, tested the coils, etc. though and haven't found anything.

[Squeeze]

Don, did you check the Emulsion Tubes for wear e.g. unround Borings ??

 

 

Someone mentioned it these Days. I know from the BDST38 Mikunis, these Carbs a know for a quick wear of the Emulsions Tubes, but not ours.

 

But, if these Emulsion Tubes, aka the Needle Jet, the Tubes in which the Jet Needle runs into, is worn, the Gas can drip into the Intake and will cause a massive Drop in Mileage and a bit crappy Feeling in lower RpM and no good Throttle Response.

[Freebird]

Yes, as well as I knew how to. I saw no wear on anything and the carbs were very clean inside.

[GeorgeS]

Why is it important ???

 

I think its because of Barometric Pressure,

 

The Hight of the fuel, is important, because barometric pressure

is what forces the fuel into the carb.

 

I don't know the details, but I remember reading about this once.

 

So the fuel level is supposed to be set, for Average Barometric pressure. ( which obviously changes with weather, and altitude. )

 

Do some research on Basic Carburator theory. It should be someplace on the internet.

[Yammer Dan]

Now that your done with that do you think you need some more practice??? I know a 1st Gen that needs cleaned........

 

Just kidding it looks like next week I may finally get a couple days off back to back and I WILL get to hear "New" bike run!!! Don't like to start something like that if I don't have time to complete it. The "Shady Lady" needs a few miles on her.

[hipshot]

"SHADY LADY"????????

WHAT IS THE DEAL , DAN?

NOT EVEN one BLUE PART ON HER?

 

next year, you and i have some catching up to do, mileage wise.

hell , i might even ride up and spend the day with "redneck".

but then i'd have do do like the tiger done,only with my eyes. they'd need washing out.

 

lol

just jt

[Yammer Dan]

There is going to be a few blue spots hidden here and there. Got some tabs that need replaced.

[Cougar]

ummm ..... errrrr.... Next time try using that thing

that is hanging off your belt and CALL Silly!!

 

My email was on all weekend as well!

 

(did the write up help at all?)

 

I hope all is better now!

 

Jeff

[Bvinson]

I just did the same carb adjustment last weekend to mine (all day job). Cleaned the pilots and set the floats. Something I wanted to mention is that when I removed my air induction box from the carbs one of the rubber boots was not fully around the throat of the carb. So, from what it looks like to me that cylinder has been sucking some dirty air ever since it was new. It has never been to the shop for anything other than the trunk replacement. That tells me it was assembled that way.

 

If you want to check yours it will be a pain but you only have to tear it down to the induction box under the tank. Just pull it, flip it over and you will see a crushed part of the rubber boot that fits over the carb.