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Author Topic: cut slides pic.  (Read 949 times)

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Offline Don R

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cut slides pic.
« on: November 27, 2021, 06:33:01 PM »
 These were apparently on the RC 836 motor before the 29 smoothbores. I'm curious what this would accomplish. The carb bodies don't seem to be bored at all.  I'm holding it open a little in the pic. to show the notch.
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Offline gschuld

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Re: cut slides pic.
« Reply #1 on: November 27, 2021, 08:00:42 PM »
Open the throttle wide open and check the underside of the slide.  That slide looks to be modified like a Mikuni non smoothbore slide.  I’m curious if there is something filling the void in there.  I have a suspicion.

George

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Offline Don R

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Re: cut slides pic.
« Reply #2 on: November 27, 2021, 08:14:35 PM »
 I don't think there is, but looked in the smoothbores and see what you're talking about. When these are full open, the notch smooths the part of the slide that still extends down into the bore. My pics will upload soon.
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 You don't need a weatherman to know which way the wind blows.

Offline PeWe

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Re: cut slides pic.
« Reply #3 on: November 27, 2021, 11:53:56 PM »
This might help to find out why the throttle cutaway was modified. It affect throttle lifts 1/8 - 1/2.
https://howtomotorcyclerepair.com/how-to-tune-throttle-valve-cutaway/
« Last Edit: November 28, 2021, 12:35:11 AM by PeWe »
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CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Don R

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Re: cut slides pic.
« Reply #4 on: November 28, 2021, 07:26:44 AM »
This mod seems to streamline the lower part at nearly wide open throttle. I don't think they changed the bottom of the slide but could be wrong.  Still fun learning and thanks for the clues. The top of the opening does show a different finish. The arch may be modified too.
« Last Edit: November 28, 2021, 10:49:49 AM by Don R »
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No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.
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