how does my restrictor work

[mrr1]

evenin' all

purely out of mechanical inquisitiveness I decided to take a look at my 33 bhp restriction kit on my 600 fazer - just to understand a little better how it all works you understand. I have the carb body sort - not the good old washer between the carb & the manifold type. According to the destructions the restriction kit consists of a different spring, different needles and some throttle stop "plates". I've stripped the carbs out but can't see for the life of me how the plates stop any throttle valve movement. The needles go into the slide body and have about 3- 4 mm of movement into the slide body before the inner spring bottoms out against the inner plug / clip.Can anyone explain how this thing works so that in a year or so's time I can safely remove it??
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TRX850, TDM900, ST1300, CB650SC Nighthawk, ragtop Saab, gym membership, messy divorce, large chested blonde fiance
Damn, I'm loving my midlife crisis.

[That_Hornet]

[mrr1]

[Kickstart]

Hi

The bits on the slide would, I expect, just be there to adjust the fueling (and surprised it would need it).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[mrr1]

thanks keith - am I right about the thin metal plate? Is it there to stop the pressure under the diaphragm building up & lifting the pin higher?
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TRX850, TDM900, ST1300, CB650SC Nighthawk, ragtop Saab, gym membership, messy divorce, large chested blonde fiance
Damn, I'm loving my midlife crisis.

[Kickstart]

Hi

If there is still a hole then I would expect it ti still rise just as far, just probably change the speed it rises.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[mrr1]

this is a view of one of the carbs with the plate in & out
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TRX850, TDM900, ST1300, CB650SC Nighthawk, ragtop Saab, gym membership, messy divorce, large chested blonde fiance
Damn, I'm loving my midlife crisis.

[Kickstart]

Hi

Other than those not being the same carb ( ), not sure. All I can see that doing is shimming up the slide slightly.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[mrr1]

oh yes - sorry for not pointing that out - of course they're not the same carb.........

the hypothetical plate in the hypothetical carb appears to block the two hypothetical holes to the upper right. Once this hypothetical plate has been taken out the hypothetical bike seems to rev much more freely and very happily hits 10k - 12k rpm in 2nd & 3rd gear (hypothetically).
____________________
TRX850, TDM900, ST1300, CB650SC Nighthawk, ragtop Saab, gym membership, messy divorce, large chested blonde fiance
Damn, I'm loving my midlife crisis.

[Kickstart]

Hi

Think that won't make a great difference. The vacuum from the intake needs to be transferred above the diaphragm so that it lifts, and can't see that stopping that vacuum being transferred.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[mrr1]

thanks keith. all i know is that the plate out takes about a second and a half off the 0-60 time. The spring is a real toughie - definitely not the thin delicate sort I'd have expected - I can easily see how a stronger spring would change how the slide rises (or, rather, doesn't)
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TRX850, TDM900, ST1300, CB650SC Nighthawk, ragtop Saab, gym membership, messy divorce, large chested blonde fiance
Damn, I'm loving my midlife crisis.

[Kickstart]

Hi

Stronger spring will affect how far it rises, playing with the holes for the air to get through will affect how quickly it rises (but given long enough the pressure / vacuum will eventually get there).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[mrr1]

that makes total sense.

In terms of spring type how critical is it that a "genuine yamaha" spring is used? I'm loathe to pay a tenner (or more) per spring.
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TRX850, TDM900, ST1300, CB650SC Nighthawk, ragtop Saab, gym membership, messy divorce, large chested blonde fiance
Damn, I'm loving my midlife crisis.

[Kickstart]

Hi

Pretty critical. Be difficult to find another spring the same.

To be honest I would be inclined to keep an eye out for a cheap set of carbs on Ebay.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing