Fuel screw idle drop test

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chromedome
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Fuel screw idle drop test

Post by chromedome »

For no reason other than I can't leave well alone, I decided today to check/adjust my fuel screw settings, using the excellent guide on this forum.

Armed with a bevel drive 90° screwdriver, bike warmed up, and the aforementioned instructions, I set the idle to around 1800rpm and began the idle drop test. Well, having screwed the front screw in fully, there was barely any perceptible drop in revs; in fact, on both cylinders, there was little change in either direction. The carbs are perfectly balanced.

From reading the guide, I expected a substantial change in the revs, but mine was so minimal it would have been hard to choose an accurate number of turns that hit any perceived sweet spot.

So, put them back to where they were hopefully - even with the right tool they are a bugger to adjust.

Anyone got any thoughts on why the rev change was barely noticeable?
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sirch345
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Re: Fuel screw idle drop test

Post by sirch345 »

chromedome wrote: Sun Jul 09, 2023 3:03 pm For no reason other than I can't leave well alone, I decided today to check/adjust my fuel screw settings, using the excellent guide on this forum.

Armed with a bevel drive 90° screwdriver, bike warmed up, and the aforementioned instructions, I set the idle to around 1800rpm and began the idle drop test. Well, having screwed the front screw in fully, there was barely any perceptible drop in revs; in fact, on both cylinders, there was little change in either direction. The carbs are perfectly balanced.

From reading the guide, I expected a substantial change in the revs, but mine was so minimal it would have been hard to choose an accurate number of turns that hit any perceived sweet spot.

So, put them back to where they were hopefully - even with the right tool they are a bugger to adjust.

Anyone got any thoughts on why the rev change was barely noticeable?
Are you using the rev counter on the bike to see any changes in rpm’s? as that won’t register the fine reductions or increases for you to see. You need a multi-meter type tool that will register small changes in rpm’s,

Chris.
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