New to me gt750a

Post your Kettle problems here and cures
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

teazer wrote: Wed Mar 24, 2021 1:44 pm It does sound like it's lean on the main jets and that suggests either restrictions in the fuel flow, low float levels or something blocked in the carbs.

Is there a Dyno shop anywhere close to you? I would tie it to a dyno and see what's going on with the air:fuel. If it's going lean, it should be obvious.
If there's no dyno close by, pull the carbs again. Check FUEL level - you will need an adapter and length of clear tube.

You could also check fuel flow. Pull the feed tube off the carb bank and stick it into a container then turn the fuel tap to PRIME and let it flow for at least a minute. See if it keeps flowing strongly or if flow tapers off to a dribble. The filter of the fuel tap could be partially blocked or there could be a partial blockage in the tap.
Thanks teazer.
I also think that the main is lean, though i will admit i would be a little annoyed if i see crap in the bowls.
I had cleaned the tank over 4 days, just so i wouldnt have to run an additional filter affecting fuel flow LoL
I have to put in a new gasket in the petcock anyways, so i will inspect that.
I do have a spare bank of carbs. I will put the spare bowls in my ultrasonic today and may be swap them if need be.

Funny thing is my gt380m is doing the exact same, but i am waiting for a set of air filters for it. LoL
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canaletto5
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Re: New to me gt750a

Post by canaletto5 »

Is the fuel for both bikes from the same source? Kev
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

canaletto5 wrote: Wed Mar 24, 2021 7:30 pm Is the fuel for both bikes from the same source? Kev
Shell premium fuel, ethanol free, from two different places
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

Checked flow, flow is great.
There was some fine rust particles in the sediment bowl again.
Tank will get a rinse, again to clear that. Probably some stuff that loosened up from being in service.

Carbs are now off.
Let me know anything in particular i should look for.
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canaletto5
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Re: New to me gt750a

Post by canaletto5 »

Check the needle jet seat o rings. They are tiny and can disintegrate with age. Weird you should get the same problem with the 380. Slide throttles versus CV's. Are you high up in the Rockies? :lol:
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

canaletto5 wrote: Wed Mar 24, 2021 11:18 pm Check the needle jet seat o rings. They are tiny and can disintegrate with age. Weird you should get the same problem with the 380. Slide throttles versus CV's. Are you high up in the Rockies? :lol:
I had put in new o rings from suzuki last time i went through them.
No, not in the rockies, i am at about 2500 above seal level.
Bowls are perfectly clean, so are the jets and passages.
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

Could a really tiny pin hole in the slide diaphragm may have caused this ?
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

canaletto5 wrote: Wed Mar 24, 2021 11:18 pm Check the needle jet seat o rings. They are tiny and can disintegrate with age. Weird you should get the same problem with the 380. Slide throttles versus CV's. Are you high up in the Rockies? :lol:
Gt380 i am accounting to the absence of airfilters
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Salmanz8
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Re: New to me gt750a

Post by Salmanz8 »

Havnt checked the float level with a guage, but seemed ok on disassembly. All jets and passages are clear.
Infact doesnt even look like these floats have ever been adjusted since new.
No abnormalities. Emulsion tubes are clear.
Upon really close inspection, i found a very tiny hole in one of the slide diaphragms. I had to gently stretch the rubber to see the hole, but only in one. The other two are fine.
Needles have some wear about 2/3 up from the tip, but i dont think thats a serious issue on a stocker.

Either its the slide not lifting all the way, or the floats too low ( unlikely )
Someone tell me i am not crazy.
These are simple carbs, i am scratching my head.
I was really hoping for some catastrophic junk in the bowls.
I tried to uploaf pics, but my phone camera photos are too large
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canaletto5
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Re: New to me gt750a

Post by canaletto5 »

Is the vacuum pipe from the tap to the carbs ok? No kinks or splits? If you leave the tap on Prime, do you still get the same problem?
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