Jetting Pointers

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rgvsp
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Jetting Pointers

Post by rgvsp »

I know jetting depends on location and climate, I'm just looking for some general pointers and a direction to go.

Bike is stock except for race exhaust, larger (Katana 600/750 I think) air filter element and very mild head work.

Jetting is stock except mains raised to 107's from 100.

Up top the bike runs great. Bike idles fine and pulls away from stops fine. Huge hole though in middle. Doesn't want to go much at all. Almost like a two stroke waiting for it to come on the pipe.

I lowered the needle clip one position (4) and didn't see much improvement.

Suggestions? Anyone ever put completely different needles in?
lizard821000
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Re: Jetting Pointers

Post by lizard821000 »

maybe slap it on the dyno mate.....see whats what

could be a lean surge, as appose to a rich bog!?

know nothing about these bikes tbh but jetting is jetting, youd have to wait to hear from a more knoledgable gsxr member here if this is a common problem and a fix, as i dont know, id imadging you have some knoledge on jetting too going by the rgv250 on your bike list. 8-) cool bike! :peace:
Andy
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Re: Jetting Pointers

Post by Andy »

rgvsp wrote:I know jetting depends on location and climate, I'm just looking for some general pointers and a direction to go.

Bike is stock except for race exhaust, larger (Katana 600/750 I think) air filter element and very mild head work.

Jetting is stock except mains raised to 107's from 100.

Up top the bike runs great. Bike idles fine and pulls away from stops fine. Huge hole though in middle. Doesn't want to go much at all. Almost like a two stroke waiting for it to come on the pipe.

I lowered the needle clip one position (4) and didn't see much improvement.

Suggestions? Anyone ever put completely different needles in?
Putting a more efficient exhaust on any motor do`s not mean you have to go up on the mains. My advice would be go back to standard mains and try raising the needle until your happy with the results. Hesitation is lean ,soft and fluffy is generally rich. I`ve never had to go much more than 1/2 sizes on mains with a standard airbox, un less it was ram-air and the last time i looked at a 76 it was`nt
Andy :grin:
rgvsp
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Re: Jetting Pointers

Post by rgvsp »

I appreciate the info guys. This is definitely a hesitation in the middle
lizard821000
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Re: Jetting Pointers

Post by lizard821000 »

try lifting the needle then, not lower it :)
rgvsp
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Re: Jetting Pointers

Post by rgvsp »

Lizard,
I had a local friend tell me that as well. if it gets worse it is obviously lean. If it gets better, well my judgement can't be trusted.
lizard821000
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Re: Jetting Pointers

Post by lizard821000 »

give it a go mate, a surge or hesitation normally points to lean, so raising the needle will allow more fuel in.

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