Author Topic: Need help: Dual cable, 1/4 turn quicker throttle assembly recommendations.  (Read 1601 times)

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Offline dragracer

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I need a 1/4 turn throttle assembly for my 34mm Mikuni flatslides.  Anyone have a recommendation?? My current setup has a wide open throttle switch modification but it's a full turn throttle.  I can move the WOT switch onto the carbs if necessary but I definitely need the quick throttle. I don't think I'm locking down on every pass because of the extend reach I have now.

Let's hear your thoughts fellas. Thanks in advance.

Offline Don R

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 My old pile of parts came with two single cable quick turn throttles but they are both pretty trashed. I'm interested too. Neither has a kill switch, that won't fly.  I'm seeing motion pro for $27 or G2 ergonomics which is aluminum billet $70 to 80. Never owned either.
« Last Edit: December 06, 2021, 09:09:54 PM by Don R »
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Offline dragracer

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My old pile of parts came with two single cable quick turn throttles but they are both pretty trashed. I'm interested too. Neither has a kill switch, that won't fly.  I'm seeing motion pro for $27 or G2 ergonomics which is aluminum billet $70 to 80. Never owned either.

Single cable throttles i have. I bought a new dual pull throttle with the new carbs which has less travel than the switched throttle. Id like to have a nice dual cable quick turn throttle so its easier to lock down right off the launch.

Don, MPS sells nice kill switches with teethers. FBR shop and Pingel also sell nice pieces. I have an FBR shop kill on the new build. Its a two piece witch makes mounting easier.

Offline bwaller

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I use a Yamaha R1 (2000?) throttle tube with a Motion Pro housing (01-0058) and cables (pull 01-0233, push 01-0234.

The R1 tube "cam" is larger and quickens the throttle to 95 degrees or so. It's not without a little work though. The housing interior needs to be ground some to fit the tube but isn't difficult. Their cable inner wires are longer so worked perfectly with the R1 tube and my Mic smoothbores.  Works a charm.

Offline slikwilli420

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I use the Domino throttles myself. Quickest action and very high quality.
All you gotta do is do what you gotta do.

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Offline Zunspec

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I use the Domino throttles myself. Quickest action and very high quality.

+1 for the Domino twin pull, 1/4 turn throttle (sometimes referred too as "TZ" style).  I use it for both 34mm and 38mm Mikuni round slides on my T500 racer.  Of course it is just the throttle, no secondary switches etc.

Cheers  Geoff

Offline madmtnmotors

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I'm pretty sure I used the 2006-2009 R6 throttle tube:

https://www.amazon.com/Motion-Pro-Throttle-Tube-2006-2009/dp/B07HNWPQGK/ref=sr_1_4?keywords=r6+throttle+tube&qid=1638966872&sr=8-4

I seem to recall taking a Dremel to a portion of the cable groove, but I don't remember whether it was actually rubbing the stock throttle housing or if I did it just to make sure it wouldn't rub. I didn't cut the groove down very much, just a little at a time until I was happy with it. Be sure to check fitment with a loose pull cable installed, you want to make sure there is no binding before hooking up the carbs.


Some discussion in this thread about possible clearancing of the stock throttle housing depending on the 1/4 turn solution used:

http://forums.sohc4.net/index.php/topic,60883.0.html

I may have done some clearancing of the stock housing but would have to take it apart to confirm.
« Last Edit: December 08, 2021, 05:05:04 AM by madmtnmotors »
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Offline MRieck

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I use a Yamaha R1 (2000?) throttle tube with a Motion Pro housing (01-0058) and cables (pull 01-0233, push 01-0234.

The R1 tube "cam" is larger and quickens the throttle to 95 degrees or so. It's not without a little work though. The housing interior needs to be ground some to fit the tube but isn't difficult. Their cable inner wires are longer so worked perfectly with the R1 tube and my Mic smoothbores.  Works a charm.
I have made this swap on several bikes. Pretty sure I have several new R1 throttle tubes on hand.
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Offline Tracksnblades1

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Aftermarket Honda CR & CRF 1/4 turn single cable throttle assembly come with interchangeable cams.
I’m sure your looking primarily for the quick WFO position, but these cams can allow for some more throttle finesse for big hit singles in the 1/8 to 3/8 throttle range. It can be hard to distinguish any big differences between 3/4 and wfo on some engines..
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Offline PeWe

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Re: Need help: Dual cable, 1/4 turn quicker throttle assembly recommendations.
« Reply #9 on: December 09, 2021, 11:40:07 AM »
My Mikuni TMR32 get WOT in max 1/4 turn.  Strange if RS34  need more twist of the grip.

CB750 K6 stock throttle stuff with cables. Had to modify one extra nut to lock front cable adjuster on carbs.

Care during take offs and low gears, If I sneeze risk for a wheelie ;D
More twist should be more relaxing for me ;D

« Last Edit: December 09, 2021, 11:54:00 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
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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 scottly

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My quarter-turn throttle with Webers was also very abrupt at small throttle openings like up to 1/8 throttle, so I reshaped the cam to make it more progressive, with a smaller diameter at the first part of the travel. I cut it using two hacksaw blades in the holder to give a wide enough groove for the cable. It added maybe 1/8 turn to full travel, but is more civilized on the street.
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Offline PeWe

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.....
I cut it using two hacksaw blades in the holder to give a wide enough groove for the cable. It added maybe 1/8 turn to full travel, but is more civilized on the street.
I forgot this mod!
I have done it after a hint on this forum. I guess it was you who helped me that time. ;)
It helped, it was worse before ;D

Maybe not enough space for the other way making the cam bigger for quicker response?

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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  I recently had to narrow the bullet on the end of the cable, this bike spent a long time in a barn and with the quick turn single cable it's difficult to turn. After the bike is running, I'll spend more time on cables and carbs. Thanks for the tips.
  I looked up the tether switches also. Thanks for the info Frank. My old drag bike has unknown brand ignition contact points on the handlebars and a piece of leather between the points tied to a lanyard to ground the mag in case of a get-off.
« Last Edit: December 10, 2021, 08:42:37 AM by Don R »
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Offline dragracer

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  I recently had to narrow the bullet on the end of the cable, this bike spent a long time in a barn and with the quick turn single cable it's difficult to turn. After the bike is running, I'll spend more time on cables and carbs. Thanks for the tips.
  I looked up the tether switches also. Thanks for the info Frank. My old drag bike has unknown brand ignition contact points on the handlebars and a piece of leather between the points tied to a lanyard to ground the mag in case of a get-off.

Don, I've also used a tether kill that I bought from a boat supply dealer. It's a basic plunger type and can be bought in normally opened or closed styles. I think they use them on small Jon boats with outboard motors. They were fairly cheap.