weak float valve springs?

[EricHa]

Help Mr. Wizard....I did some searching on my issue, but may be using the wrong terminology. This my first try at carb tuning and I really need help from the collective. Background is, I had my carbs rebuilt from an internet guy (I know, I know ). I mounted them and the bike fired up to a steady 1200rpm idle, but rich. Setup is SF with Jardine 4 into 1 with baffle, airbox with K&N element. Low mileage but sat in a barn for years and some contacts may be rusty. I installed Dyna 3 ohm coils and made new plug wires with NGK caps.

The rebuilder left the stock 137 mains and 42 pilots. Pilot screws were set to 1.5 turns out. I did an inital sync but left the pilot screws alone. The bike is rough and sputtery up to 3000rpm then cleans out, though not that great. Wide open throttle from 4k and up is very spotty, hard to discern (for me). All four plugs are black and sooty. I had the gap wrong at first, but have corrected them to .75mm.

I decided to check the float levels and removed the carbs. Three carb float levels (from gasket level) are at 7/8" or 22.25mm. #4 float is at 1" or 25.4mm. I was starting to bend tangs when I noticed that the weight of floats are depressing the needles, but #4 is more firm and supports the weight of the float.

I'm wondering how to proceed, replace float valves? I am leary of removing the float pins, because I know the posts can be broken. He did leave the pins out just a bit, possibly for ease of removal. Any help is much appreciated.

[bikerphil]

Take a small pair of side cutters (dykes) and grab the head of the float pin and pry it out. Try setting all your floats to 1", carbs upside down, bowl gasket removed. As long as all the floats are the same height, the differences of the springs in the float needles should not matter.

Edit: It does have brass floats correct?

[tom clisham]

Eric:

Just squeeze the float pins at the large end, between the post & the pin end with a diagonal cutter. Gently squeeze & the pin will move. After that it will slide right out. Never fails. You don't have to put any pressure on the post this way. Give it a try.

[EricHa]

Take a small pair of side cutters (dykes) and grab the head of the float pin and pry it out. Try setting all your floats to 1", carbs upside down, bowl gasket removed. As long as all the floats are the same height, the differences of the springs in the float needles should not matter.

Edit: It does have brass floats correct?

Thanks Phil. I will do that. So even though the weight of the float (upside down) is depressing the needle "pin" in some but not all, it won't matter as long as the floats measure out at 1"? I will also remove the gaskets to do this.

[EricHa]

Just squeeze the float pins at the large end, between the post & the pin end with a diagonal cutter. Gently squeeze & the pin will move. After that it will slide right out. Never fails. You don't have to put any pressure on the post this way. Give it a try.

Hi Tom. Maybe I will need that set of yours if I screw this up.

[bikerphil]

Thanks Phil. I will do that. So even though the weight of the float (upside down) is depressing the needle "pin" in some but not all, it won't matter as long as the floats measure out at 1"? I will also remove the gaskets to do this.

Hard to say for sure, sometimes those spring pins get stuck because they are gunked up with dried fuel deposits. Maybe they can be loosened up by spraying some carb cleaner on them. You do have brass floats, correct? If you want to go with new ones, here they are...

http://www.z1enterprises.com/Mikunit...amaha-310.aspx

[EricHa]

Sorry, yes brass floats. The #1 through #3 floats look to be set around 1" as they engage the float pin. They just seem weak when depressing them. The #4 seems firm.

[bikerphil]

Don't push down on the floats and compress those springs when setting them. Let them sit naturally and set to 1" to the highest part of the float.

[EricHa]

No, I was holding the float up until it touched the pin, and when I let the pin support the weight of the float it depresses a significant amount on #1 2 and 3. The springs work, just very weak. That just doesn't seem right, from my noob perspective.

[TADracer]

A note on the float pins

Once you get them removed you do not have to press them back in tightly (they do this at the factory). Just insert them through the holes because once the bowls are on they are captive. Next time you must remove them it is a simple fingertip job.

[EricHa]

Will do, thanks Mike. I'll give the standard float level adjustment a go, and I guess I can alway get new ones from MikesXS if necessary.

[natemoen]

Or you can.ground off the little flare on the shaft so It is no longer tight.

[EricHa]

ok, I got the floats adjusted to 1" without the gasket, or around 15/16" with. Will get the carbs back in and hopefully be able to test this weekend. Thanks for the advice so far.

[natemoen]

You need to be a but more precise than that. You are almost 1/8" short. That is going to be a bit on the rich side.

[crazy steve]

You need to be a but more precise than that. You are almost 1/8" short. That is going to be a bit on the rich side.

+1 on that..... You need to be within .040" of 1", that's the allowable variation.