Mikuni Adapter on a Cool /2 Custom.

sithot
Posts: 16
Joined: Fri Oct 27, 2006 3:00 am

Re: Mikuni Adapter on a Cool /2 Custom.

Post by sithot »

Looking forward to your progress.

OT:

FWIW, I understand these are Aermacchi manifolds holding the Dellorto carbs. This is a fantastic bike belonging to Scott Williams.
http://weissundblau.blogspot.com/search?q=R75
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"In regione caecorum rex est luscus"

www.pbase.com/tdb

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schrader7032
Posts: 7315
Joined: Fri Oct 27, 2006 3:00 am

Re: Mikuni Adapter on a Cool /2 Custom.

Post by schrader7032 »

Charlie -

I've lost track...why are you headed down this path?
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

ferrarirobinson
Posts: 23
Joined: Thu Mar 08, 2018 8:43 am
Location: Lynchburg, VA

Re: Mikuni Adapter on a Cool /2 Custom.

Post by ferrarirobinson »

Fair question.
Hard cold weather starting (and leaky carbs) for a regular rider.

Charlie
Charlie

ferrarirobinson
Posts: 23
Joined: Thu Mar 08, 2018 8:43 am
Location: Lynchburg, VA

Re: Mikuni Adapter on a Cool /2 Custom.

Post by ferrarirobinson »

And here is as close as I’ve come so far to my goal.

You may need to rotate photos 90°.

AFCD33E3-4119-44DC-9B67-5815CBF1CE11.jpeg
32396FEC-EEB3-46FC-BB24-A3A9713EB4AA.jpeg


Certainly seems like an improvement. When the weather turns cool to cold the “proof will be in the pudding” as to Cold Weather Starting.
Ergonomics need attention and since the K75’s don’t need attention right now I can ride the R60 also and tweak at my leisure.

Charlie
Charlie

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malmac
Posts: 440
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Re: Couldn’t find proper stud

Post by malmac »

ferrarirobinson wrote:
Fri Feb 28, 2020 7:08 am
Couldn’t find proper stud spacing from the multitude of Mikuni Adaptors. Closest fit was from Oz (Australia) and required pulling carb head mount studs and had a 28mm throat at the mounting end. The head opening on my R60 is 26mm. Maybe a step is not too bad but smooth is smooth, so my design is 26mm. It also is bolt on and take off using original mounting studs.

Charlie
Charlie

Should I assume that you made these using a CNC machining centre?

Lovely finish on the work.

Mal
mal - R69s
Toowoomba- Australia

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schrader7032
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Joined: Fri Oct 27, 2006 3:00 am

Re: Mikuni Adapter on a Cool /2 Custom.

Post by schrader7032 »

When altering the intake track, you could be affecting the standing wave patterns that develop in the air/gas flow to the engine. It may result in a "trough" of air/gas will be in front of the intake valve just as it opens, thus resulting in poor performance.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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San Arthur
Posts: 477
Joined: Sun Apr 22, 2007 2:08 pm

Re: Mikuni Adapter on a Cool /2 Custom.

Post by San Arthur »

Mikunis look "different" in non OEM motorcycles, but it makes everyday riding and cold starting soooo much easier.

R90S use Dellorto carbs and I think the RS 255 Kompressor used Amal GP carbs. And yes a perfectly tuned Bing can work flawless. You could also with the right flange install a modern Bing. Once tuned you can swap a carburetor set in a few minutes. One for show and for riding.

A few years back I installed a Mikuni on my Gold Star and it make my everyday riding at slow speeds easier and I love to have an idle circuit.

Image

We adapted and modified the velocity stack at the museum.

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San Arthur in San Antonio, Texas
'58 R26 '76 R90S '94 R100GS/PD

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