Float Height

General discussion about Street two-stroke Suzuki motorcycles.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Float Height

Post by Coyote »

Is there a tolerance on float height? +/_? I have never seen a tolerance on the float height. Is there one? Getting both float lobes parallel to the world (seem to always be twisted) and getting them spot on per book can be an all day task - especially when the needle springs are spongy. Not much info on those float needle springs, but it seems to me that stiff springs would shut off later than soft ones. What's right and what's wrong?. I've had a few rebuild kits that had very stiff springs. On old carbs that had been run for years (like mine) the springs are very spongy
I used to have a super glued needle making the spring solid. I used this to set float heights, swapping it out after setting. Can't find it. Just as well. They're all different anyway. I was just thinking. If a guy had a little tiny o-ring, he could put it over the spring post, pull the post out and roll the o-ring down and essentially make a solid pin for setting purposes. Use the o-ring on all but don't forget to remove. :roll:
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Float Height

Post by Coyote »

Never mind. I have a triples carb book that was published after the carbs were changed in 74. The height is called out as 1.01 +/_ .04 So that's .97 - 1.05 Quite a bit really. It also clearly states NO Gasket!.
I am lucky enough to have a height gauge after years of eye balling. Son cut it out on a laser at work. The legs are 1.01 long and the tips fit on the bowl cut out surface on the bodies. Just stand it on there and slide it back and forth. Adjust the tang till the gauge just touches passing over the float. Just set these.

Image
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
User avatar
Alan H
Moto GP
Posts: 3250
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 4 x GT550s - J, M, A, B.
Location: The Republic of South Yorkshire

Re: Float Height

Post by Alan H »

Coyote wrote:Never mind. I have a triples carb book that was published after the carbs were changed in 74. The height is called out as 1.01 +/_ .04 So that's .97 - 1.05
Remember that they work in millimetres, so as 40 thou is 1 millimetre, or 1 thou is 0.025mm (near enough).
0.08mm is 3.2mm.
If you are still working in inches, there's a problem.
Don't worry, we still have issues with metric and Imperial measures too!

BTW, I always use a gasket or it just doesn't work as it doesn't seal.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Float Height

Post by Coyote »

No Alan, that is inches. The metric call out is 25.75 +/- 1mm, And of course I use gaskets. I meant no gasket in place when setting the float height. Or were you just yanking me around? :wth:
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
User avatar
Alan H
Moto GP
Posts: 3250
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 4 x GT550s - J, M, A, B.
Location: The Republic of South Yorkshire

Re: Float Height

Post by Alan H »

Coyote wrote:No Alan, that is inches. The metric call out is 25.75 +/- 1mm, And of course I use gaskets. I meant no gasket in place when setting the float height. Or were you just yanking me around? :wth:
No, not this time!! I misunderstood the comment.
Remember that we are two nations separated by a 'common' language here!!!
Think of how stupid the average person is, then realise that half of them are more stupid than that.
bpeck27
On the street
Posts: 24
Joined: Sun Nov 30, 2014 3:41 pm
Country: USA
Suzuki 2-Strokes: GT550, TS400
Location: New Jersey, USA

Re: Float Height

Post by bpeck27 »

I had a problem with my 550 not idling after I set the floats to the 1" spec. height. Long story short, I finally figured out that the idle circuit wasn't picking up enough fuel. I ended up with floats set to 27/32" and it's running and idling just fine, thank you!

But Coyote brought up the issue of the inlet needle springs and I'm wondering if those soft springs would account for my float settings being so far off of the specification. Any thoughts?
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Float Height

Post by Coyote »

I'd like to know the answer to that too. I just set mine to the book 1.01, but the springs are terrible soft. I wonder if I am going to be faced with the same misery. Won't be running for a while yet.
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
GT750Battleship
Road race school
Posts: 841
Joined: Tue Feb 19, 2013 2:45 am
Country: Australia
Suzuki 2-Strokes: Suzuki GT750A 1976
Location: Sydney New South Wales

Re: Float Height

Post by GT750Battleship »

8) Hi,while setting my float heights yesterday I noticed how weak the needle jet spring action was,compared to the new ones that come in the carby kits !
Cheers,
Roger
GT750Battleship.
yeadon_m
Road race school
Posts: 792
Joined: Sun Aug 05, 2012 1:18 am
Country: UK
Suzuki 2-Strokes: GT380B, GT550B, GT750A, GSX1400

Re: Float Height

Post by yeadon_m »

The key (ster :-) )thing is not to mix the Suzuki (Mikuni) float valves and any different ones. If you do, setting the float heights the same may not result in the same FUEL height in the bowls.
Mike
GT750Battleship
Road race school
Posts: 841
Joined: Tue Feb 19, 2013 2:45 am
Country: Australia
Suzuki 2-Strokes: Suzuki GT750A 1976
Location: Sydney New South Wales

Re: Float Height

Post by GT750Battleship »

8) Hi Mike,good job I went with new everything (Cruzin Image Carb Kit) yesterday :up:
Regards,
Roger
GT750Battleship.
hahahaurugly
On the street
Posts: 44
Joined: Wed May 27, 2015 3:27 pm
Country: usa
Suzuki 2-Strokes: 1973 GT380

Re: Float Height

Post by hahahaurugly »

Good luck with that cruzin image junk. The gaskets swelled to unusable in a few weeks and half the parts were wrong enough to not be usable.
User avatar
tz375
Moto GP
Posts: 6212
Joined: Mon Nov 03, 2008 10:47 am
Location: Illinois

Re: Float Height

Post by tz375 »

Genuine Mikuni parts are generally available - why try anything else? :wink:
GT750Battleship
Road race school
Posts: 841
Joined: Tue Feb 19, 2013 2:45 am
Country: Australia
Suzuki 2-Strokes: Suzuki GT750A 1976
Location: Sydney New South Wales

Re: Float Height

Post by GT750Battleship »

:) hi,Cruzin Image Carbruettor Kits can't be all bad,my friend is a motor mechanic,after 45 years of looking after trucks,cars,motorcycles,heavy farm equipment I think he knows junk parts by now,the only thing he didn't like was having to make a small cut in the bowl gaskets,to get them to seat nicely round the float jet housing,I did notice the bowl gaskets are marked made in the USA :P
Cheers,
Roger
GT750Battleship.
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Float Height

Post by Coyote »

did notice the bowl gaskets are marked made in the USA :P
Must be a typo.
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
Post Reply