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"Thee" SU Float Level Tool

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Never saw that before, wonder if it's from England. Nice packaging, etc.

I would rather have the glass extend up a little higher, so it a bowl overflowed (it can happen while adjusting floats) the gas would run out the vent on the lid (through a hose routed to a catch can or container) instead of out the glass. Also, looks like it would obstruct an air cleaner, stock or otherwise. A sight glass has other uses besides setting the floats. It can be useful sometimes to verify that there's the right amount gas in the bowls (that the valves are working properly), while doing a test drive.

There's also a nifty sightglass from M-C for about the same price that has the right thread I think; it would probably obstruct an air cleaner, though.

I bought a low-tech version from ZTherapy for about half that price. Had to modify one of them so it wouldn't leak (maybe i got a bad one), but it can set so the plastic tube outlet is higher than the lid vent. Also, it can be used with an air cleaner, K&N's anyway.

Pretty cool, though.

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Right, Arizona....

The M-C ones are glass, otherwise I would have got them. Probably not for automotive. Kind of big, too, probably wouldn't go behind the K&N's.  If these would go behind the K&N's maybe I would just leave them there, with a cap or plug or something.

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Figuring out the fuel level in the float chamber is easy.  What we really need is for somebody to come up with a mechanism that allows the float level to be adjusted needing to remove the float chamber lid.

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If I was at Hitachi or SU "back in the day"  I would have made the bowls so the whole darn thing is adjustable up and down by 1cm.... forget bending the float tabs over and over again.

Mikuni and SK have externally adjustable floats but it is a somewhat complex set of parts and the bowl is internal.

Just raising and lowering an external bowl seems to be the easy route for the early SU design.

Edited by 240260280

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44 minutes ago, 240260280 said:

If I was at Hitachi or SU "back in the day"  I would have made the bowls so the whole darn thing is adjustable up and down by 1cm.... forget bending the float tabs over and over again.

Mikuni and SK have externally adjustable floats but it is a somewhat complex set of parts and the bowl is internal.

Just raising and lowering an external bowl seems to be the easy route for the early SU design.

I've thought about making the bolt that mounts the fuel bowl into an eccentric/offset bolt with a 0.5 cm offset... Someday I'll have time to make one...., two I guess.

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Site, That won't work. You need to change the height of the float with respect to the height of the nozzle. Any changes you make with the routing of the tubing will have no effect. Think "water level" when building a deck. The tube position/routing doesn't matter.

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zKars, An eccentric bolt on the bowl mount is a really interesting idea. I think I'll poke around with that too when I get a chance. So simple!

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19 minutes ago, Captain Obvious said:

zKars, An eccentric bolt on the bowl mount is a really interesting idea. I think I'll poke around with that too when I get a chance. So simple!

That's me, simple. 

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Making the pivot point of the float adjustable - threaded "ears" or posts with external screws maybe - seems like it could have possibilities.

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On 3/25/2017 at 9:21 AM, zKars said:

I've thought about making the bolt that mounts the fuel bowl into an eccentric/offset bolt with a 0.5 cm offset... Someday I'll have time to make one...., two I guess.

I think you're may be on to something, Jim.  However, the 'bolt' (actually more like a long stud) is non-rotational because it's designed to be firmly tightened into the blind threaded hole in the float bowl casting.  That means that you wouldn't be able to rotate it to a new position (to take advantage of the eccentricity you're proposing) unless you were prepared to leave the threaded stud-to-casting joint 'loose' after you'd found the bolt orientation position you want.  Maybe a thin jamb nut?  If that would work (and I'm sure that one or all of Capt Obvious, Blue, Patcon, Grannyknot and maybe even Z Therapy are about to start work on this :P ), then it would seem that the final touch would be to slot the other end of the 'bolt' (where the lock nut) to allow use of a screwdriver to turn the bolt to make adjustments.  Adjusting sequence would be:

loosen lock nut on end of bolt

loosen jamb nut where bolt fits into float casting

turn bolt until desired  fuel level is observed inside carb nozzle

tighten jamb nut

tighten lock nut

job done

One additional thought:  I don't think the bolt offset needs to be more than 5mm.  That would provide an up-down adjustment of +/- 5mm for the float bowl.  If you set the float 'tang' adjustment to the FSM-recommended setting to start with, an additional +/- 5mm of adjustment should be more than enough to zero in on the desired fuel height in the carb nozzle.

Gentlemen: Start your lathes.  Report back here in a week, with pictures (to prove that it really happened).  Whoever wins owes me two finished prototype eccentric bolts.

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I used that Float tool and it is handy. Problem is that the tube(plastic) is epoxied in place and the fuel started to eat at it- in my case anyway. Now granted - I left them on the bowls over a couple of days while in the garage trouble shooting. If the tubes were actually threaded and tefloned in place I don't think it would have been a problem.
I did send mine back. In theory it worked well , but function was limited.
In the end- I relied on a set of depth mics and the 10 turn rule for the nozzles.


Sent from my iPhone using Classic Zcar Club mobile

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I've been thinking about the external adjustment concept a little more, and while I believe it's possible, I'm concerned about the amount of potential confusion and tuning issues it may CAUSE as opposed to fix. Just think about it... If you can externally adjust the height of the entire bowl assemble WRT to the nozzle, you can effectively get the fuel height correct even if the bowl level is in correct.

Conversely... You can get the fuel level WRONG even if the bowl level is CORRECT.

Can you just imagine the amount of documentation required to keep that situation under control?   LOL

Haha!! Who want's to try to explain how to tune that to people who already don't really know what they're doing?

I've got my nozzles six turns down and my plugs are black. Should I lower my bowls a little? Please advise!!!

Edited by Captain Obvious

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LOL I was thinking the same.  The reference will need to be away from the bowl as you say. A bit complex but a gauge (basically a flat piece on metal that stops at the 20mm down point which is affixed to the non-eccentric part/non moving part will do the trick.

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I agree with C.O. in post 19. Also, due to engine tilt, the fuel level in the front bowl needs to be a couple mm lower than in the rear bowl. 

For me, the thing that makes setting the floats a hassle, even with a sight glass, is bending that tang on the float to adjust the level.  Fuel level is too low so you bend it down, then it overflows so you bend it up, repeat and repeat to get it more or less right. Took me about 10 tries last time. Adjust, remove/replace the lid and run the engine each time

Seems like it would be fairly easy (OK, maybe difficult) to put a small captive screw between the tang and plastic float. The tang would be initially bent in a low position, turning the screw would raise it. You could figure how many turns would raise it one mm. Need to look at on old float to see if it would work.

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23 minutes ago, Captain Obvious said:

I've heard of them, but I've never looked into any details.

What's the big deal about those Grose jets? What makes them so cool?

"2 balls do the trick"

 

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