Gt 250 Float height measurement.

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Tapnell
On the street
Posts: 21
Joined: Tue Jul 24, 2018 3:56 am
Country: UK
Suzuki 2-Strokes: 1973 GT250
Location: Isle of Wight UK

Gt 250 Float height measurement.

Post by Tapnell »

Hi Guys....The carbs on my 73 250k are the individual float and pin type and all sources of info including Suzuki service data set the float height at 13.7mm. This is measured ( as far as I can ascertain ! ) from the casting top where the main jet screws in to what they call the tongue adjacent to the needle valve.
I’ve had to bend the tang ( which operates the valve directly ) a fair old bit to get this measurement! Now I’ve got running issues with idle and cold start up with a choke that doesn’t now seem to be working.
I’m now questioning whereabouts exactly along the float arm the measurement of 13.7 should be made. Hopefully someone can help if only to confirm or advise! Cheers
Tapnell
On the street
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Joined: Tue Jul 24, 2018 3:56 am
Country: UK
Suzuki 2-Strokes: 1973 GT250
Location: Isle of Wight UK

Re: Gt 250 Float height measurement.

Post by Tapnell »

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karl pa
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Re: Gt 250 Float height measurement.

Post by karl pa »

I don't measure float levels, the old school mechanics at my local Suzuki shop showed me to hold carb upside down like your photo, and when the tang just touches the needle plunger, the float arm should be parallel to the carb body. I would think you would have low fuel level in carb with starvation issues at the setting in the picture.
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jabcb
Moto GP
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Re: Gt 250 Float height measurement.

Post by jabcb »

Specification-6 has the carb specs for your bike: http://www.ozebook.com/compendium/techb ... %206-9.pdf
A diagram showing how its measured is on page 7 of http://www.ozebook.com/compendium/suzi/suzidata1.htm

You are correct that the spec is 13.7mm measured per Diagram B on page 7.
When checking the level, tilt the carbs a bit so that the float weight doesn’t compress the needle valve spring.
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Tapnell
On the street
Posts: 21
Joined: Tue Jul 24, 2018 3:56 am
Country: UK
Suzuki 2-Strokes: 1973 GT250
Location: Isle of Wight UK

Re: Gt 250 Float height measurement.

Post by Tapnell »

Thanks jabcd ...that’s exactly what I was after...measurement X is the opposite end of the float arm I was lead to believe from the various manuals and indeed other Suzuki material....🤞
Tapnell
On the street
Posts: 21
Joined: Tue Jul 24, 2018 3:56 am
Country: UK
Suzuki 2-Strokes: 1973 GT250
Location: Isle of Wight UK

Re: Gt 250 Float height measurement.

Post by Tapnell »

Thanks for your help Guys....Running lovely now, I’ve reset the float arms. It’s amazing the difference just a few mm make to the float level...result ! :up:
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