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GuyGraham

Is this Carb Body / Slide / Slide plate worn out?

5 posts in this topic

I remember reading on here a while back, about how the vacuum under engine braking pulls the carb slide rollers into the body, resulting in the plate that fits onto the engine side of the carb slide touching the carb body, which results in excess pressure being applied to it, and eventually they crack, which if a piece gets sucks into the engine results in serious engine damage (as would be expected)

 

I'm sure the 'test' to check if carb was worn out, was to apply pressure to the filter side of the carb slide, with it fitted to the carb, and then see if the plate which fits the carb slide is free to float or is clamped against the carb body. If its clamped against the carb body then carb is deemed as in need of replacement.

 

Have just checked mine

My slide plate does not have any float when pressure is applied to the slide from the filter side

The plate shows signs of rubbing on the carb body (which I don't think its supposed to do) as indicated by the polished areas (black coating has been removed)

20151229_141435.jpg

 

The slide itself as appears to be rubbing on the carb body, again indicated by the missing areas of coating

20151229_141422.jpg

 

Carb body has tell tale wear marks from the rollers digging into it

20151229_141544.jpg

 

 

 

Bike has 10K miles and approx 500hrs (450, 08 model)

 

Is this carb junk?

Edited by GuyGraham

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I've never heard of the 08's breaking the slide plate. But that doesn't mean much. You could probably replace the plate and go another 20,000 mi.

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I've never heard of the 08's breaking the slide plate. But that doesn't mean much. You could probably replace the plate and go another 20,000 mi.

 

A quick search on Google brings up broken 'M' plates which are what are fitted to the later FCR MX carb (the earlier 'L' plates as fitted to the slant bodied FCR were notorious for cracking), so it seems the problem still exists

IMG_5183.jpg

 

 

Anybody got experince of these billet replacements from USA ebay

http://www.ebay.com/itm/Keihin-FCR-improved-M-vacuum-release-plate-throttle-plate-/271958731296?hash=item3f5200ea20

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A quick search on Google brings up broken 'M' plates which are what are fitted to the later FCR MX carb (the earlier 'L' plates as fitted to the slant bodied FCR were notorious for cracking), so it seems the problem still exists

IMG_5183.jpg

 

 

Anybody got experince of these billet replacements from USA ebay

http://www.ebay.com/itm/Keihin-FCR-improved-M-vacuum-release-plate-throttle-plate-/271958731296?hash=item3f5200ea20

Nice find especially for us guys that run them forever.

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