honda305 Home honda305 Auctions honda305 Gallery honda305 Forum Electronic Ignition honda305 Forum honda305 Forum honda305 Forum honda305 Racing honda305 Literature

Auctions  Mailing List    Registry   Marketplace

honda305.com Forum - FULL SCREEN

honda305.com Forum

Login
□ Search
  □ CLASSIFIED_ADS
□ FAQ 
  □ SEARCH_ADS
□ 
  □ MY_ADS
Vintage Honda Owners,
Restorers, Riders and
Admirers

Ratio Rev Counter

CYP77 - Police | Race Bikes | Choppers, Bobbers and Mods
Pan47
honda305.com Member
Posts: 10
Joined: Tue Dec 25, 2012 1:40 pm
Location: Germany

Ratio Rev Counter

Post by Pan47 » Sat Jan 21, 2017 4:28 am

Hi,
now anybody what ratio the CB77 revcounter has?
Need this Information for my race CB 77.
Have try 2:1 3:1 and 5:1 nothing works.


Thanks Christian

User avatar
G-Man
honda305.com Member
Posts: 5675
Joined: Wed Mar 25, 2009 5:17 pm
Location: Derby, UK
Contact:

Post by G-Man » Sat Jan 21, 2017 11:59 am

Hi Christian

When you say nothing works, what are you comparing with?

You can check the gearing revcounter drive in the head by watching how many engine rotations it takes to make one revolution of the cable.

G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160
'66 Matchless 350 '67 CL77
'67 S90 '77 CB400F

Tim Miller
honda305.com Member
Posts: 242
Joined: Mon Jan 30, 2012 6:22 pm
Location: Pflugerville, TX

Re: Ratio Rev Counter

Post by Tim Miller » Sat Jan 21, 2017 12:06 pm

I have used CB92 race tachometers. The face reads 20:3 so, I suppose that would equally 6.666 :1 but I'm sure others will have something to say. Lol

Tim
Pan47 wrote:Hi,
now anybody what ratio the CB77 revcounter has?
Need this Information for my race CB 77.
Have try 2:1 3:1 and 5:1 nothing works.


Thanks Christian

DJM
honda305.com Member
Posts: 545
Joined: Thu Oct 09, 2003 1:54 pm
Location: Chesterfield UK

Post by DJM » Sat Jan 21, 2017 12:25 pm

20:3 is the correct ratio for these bikes.

I believe that ratio was a Japanese Standard (JIS) for use on all bikes below 500cc.

I [think] that bikes over 500cc used a more usual 4:1 ratio.

Pan47
honda305.com Member
Posts: 10
Joined: Tue Dec 25, 2012 1:40 pm
Location: Germany

Post by Pan47 » Sat Jan 21, 2017 1:38 pm

Thank you for Response

I buy the Smith replica revcounter from Scott Mitchell UK.
the first
4;1 was to slow real 6000 turns show me 2500-3000 turns

the second
2;1 was slower real 6000 turns show me 100-1500 turns

the last
7:1 ( Scott let build him for me ) show nothing

The cabel turns against clockwise. That was correct on my Smith revcounters.
I see also revcounter with Ratio 1:4 1:5 or 1:7 could this be the problem?

Pan47
honda305.com Member
Posts: 10
Joined: Tue Dec 25, 2012 1:40 pm
Location: Germany

Post by Pan47 » Sat Jan 21, 2017 1:47 pm

The one i need is a revcounter for my racebike with Diameter 80 mm for mounting on the original CB 77 /72 cabel connector.

What have you guys on your racebike mounted?


(no electric )

DJM
honda305.com Member
Posts: 545
Joined: Thu Oct 09, 2003 1:54 pm
Location: Chesterfield UK

Post by DJM » Sun Jan 22, 2017 11:56 am

Years ago I used a rev-counter off a small Kawasaki two stroke. It was the correct JIS ratio of 20:3 and worked fine. Can't remember the scale reading but it was on my race bike so must have been OK. It also came with an angled cable connection on the back which made mounting it and getting a good cable run much easier. It could have been off a KH250 or 350

Post Reply

 


 

CB-77 | CYP-77 | Road Test | Riding Log | Literature | Zen | Marketplace | VJ Survey | Links | Home