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Quadmaster 500 backfiring after jet kit. Any advice?

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Hi. I recently had to replace the diaphragm on my QM 500, so I decided to add a sigma 6 jet kit. I basically replaces the main jet with a 135 (was 130) and moved the clip on the needle down one space (as per their directions) towards the RICH direction. Now that I have it reinstalled it starts great, idles great but if you try and give it any throttle it sputters, pops and looses all power. With the choke on it will accept throttle.

This implies to me that I am running LEAN, which seems strange as I moved the needle towards rich and put a bigger jet in?

I have checked the rubber connections on either side of the carb, the carb has been out and it is CLEAN.

So any thoughts other then just "clean the carb".



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Try raising the needle another notch. If no joy, then try lowering it a notch from your initial setting.

Sent from my Z10 using Tapatalk

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Slide moves well now. . That's what i had to replace. . The old diaphragm became brittle and had a tear. But before that it ran great. Keep in mind I did add the jet kit... It's really cold here so I haven't had a chance to try moving the clip up the needle.

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If moving the clip the other way doesnt help, then I would undo the jet mod you did.

BTW, who did you buy it from? Perhaps they have pointers.

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Just thought i might be able to gain a little power with a kit and air filter. .. lesson learned. . I'm hoping Sigma 6 will take their kit back.. Didn't even come close to working no matter what the configuration. ..

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Keep us posted on how it works out for you!

Sent from my iPhone using Tapatalk

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