« previous next »
Pages: [1]   Go Down

Author Topic: Suggested timing curve setting for Dyna 2000, 1025cc  (Read 1129 times)

0 Members and 1 Guest are viewing this topic.

Offline gschuld

  • Master
  • *****
  • Posts: 2,346
Suggested timing curve setting for Dyna 2000, 1025cc
« on: June 11, 2021, 02:41:27 PM »
Ok, next question.  Timing curve for Dyna 2000.

Engine in question:

1025cc for road race application.
CycleX Ported head, 34/28 thin stem valves, beehive springs
New JE 72mm flat top pistons (10.5:1 compression). Great squish band area.
Carrillo rods
MotoGPworks 4/2/1 exhaust
New Keihin CR-31s with 29mm restrictor rings (AHRMA class restriction)
Dyna 2000 ignition with Dyna S pickup
Megacycle 125-75 cam
CycleX ProCut modified (backcut 2/3/4 etc) complete F Model trans

I recall #4 (of 5) being a popular choice, Paul in Australia races a 915cc l/CR-31s road race engine at the #3 setting.

Any thoughts on initial setup is welcome.

As always, thanks in advance

George


« Last Edit: June 11, 2021, 04:39:24 PM by gschuld »
Logged

Online Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,902
  • Bought her new 4/75
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #1 on: June 11, 2021, 06:00:08 PM »
George, I went with 4 simply because the info that came with it made that one seem the most logical.

Oh, and make sure the 4 pin connector coming from the pick up is snuggly connected to it's mate that goes to the brains. 2 of my pins backed out during connection and left me stranded on the side of I-25. 

Dyno results??
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline gschuld

  • Master
  • *****
  • Posts: 2,346
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #2 on: June 11, 2021, 07:40:13 PM »
Quote from: Jerry Rxman Griffin aka MuthaF'er on June 11, 2021, 06:00:08 PM
George, I went with 4 simply because the info that came with it made that one seem the most logical.

Oh, and make sure the 4 pin connector coming from the pick up is snuggly connected to it's mate that goes to the brains. 2 of my pins backed out during connection and left me stranded on the side of I-25. 

Dyno results??

Good points.  Thx.  Dyno session is NEXT Thursday.

George

Logged

Offline Old Scrambler

  • My CB750K3 has been in 39 States & 5 Provinces
  • Old Timer
  • ******
  • Posts: 3,807
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #3 on: June 11, 2021, 08:12:07 PM »
Mild compression and de-stroked...................I'd choose #5 and use the retard wire in the upper rpms..........Be ready to play with the trigger setting when on the dyno ;)
Logged
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline dragracer

  • Really Old Timer ...
  • *******
  • Posts: 5,101
  • CB750F Dragbike
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #4 on: June 11, 2021, 11:02:19 PM »
Quote from: Jerry Rxman Griffin aka MuthaF'er on June 11, 2021, 06:00:08 PM
George, I went with 4 simply because the info that came with it made that one seem the most logical.

Oh, and make sure the 4 pin connector coming from the pick up is snuggly connected to it's mate that goes to the brains. 2 of my pins backed out during connection and left me stranded on the side of I-25. 

Dyno results??

I never use that damn connector.  Hard wire it and save yourself a ton of problems.
Logged

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,529
  • Bike almost back to the 70's 2015
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #5 on: June 12, 2021, 12:00:18 AM »
Interesting read here! ;D
The crank trigger seems to be vital.

Now I see  if full advance happen at or after 3000 rpm is no problem.
My stock advancer with cut springs delay some making low rpm cruising smooth and even.
195-200PSI tested with a cheap compr tester, all 4 cylinders to be equal. Good when comparing cams with different overlap.
Note the numbers that are useful later if something changes.
A sudden 10-25 PSI less helped me to see time for lifting the head, replacing it..
I hope I can stay away from the buy Dyna 2000 now button! ;D
Logged
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 bear

  • Vale Bill McIntosh ......"illegitimi non carborundum"
  • Old Timer
  • ******
  • Posts: 2,575
  • Leeton in Australia
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #6 on: June 17, 2021, 06:44:07 PM »
Quote from: gschuld on June 11, 2021, 02:41:27 PM
Ok, next question.  Timing curve for Dyna 2000.

I recall #4 (of 5) being a popular choice, Paul in Australia races a 915cc l/CR-31s road race engine at the #3 setting.

Any thoughts on initial setup is welcome.

As always, thanks in advance

George




I would imagine he prefers the flatter curve because he's running methanol.
Logged
The older I get the faster I was.

Offline Tracksnblades1

  • My Son was a collegiate competition Trap, Skeet, and sporting Clay
  • Master
  • *****
  • Posts: 1,851
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #7 on: June 27, 2021, 05:15:56 AM »
Quote from: gschuld on June 11, 2021, 02:41:27 PM
Ok, next question.  Timing curve for Dyna 2000.

Engine in question:

1025cc for road race application.
CycleX Ported head, 34/28 thin stem valves, beehive springs
New JE 72mm flat top pistons (10.5:1 compression). Great squish band area.
Carrillo rods
MotoGPworks 4/2/1 exhaust
New Keihin CR-31s with 29mm restrictor rings (AHRMA class restriction)

Dyna 2000 ignition with Dyna S pickup
Megacycle 125-75 cam
CycleX ProCut modified (backcut 2/3/4 etc) complete F Model trans

I recall #4 (of 5) being a popular choice, Paul in Australia races a 915cc l/CR-31s road race engine at the #3 setting.

Any thoughts on initial setup is welcome.

As always, thanks in advance

George

What length rods did you go with..?
Do you have any Dyno time in..?
« Last Edit: June 27, 2021, 05:22:31 AM by Tracksnblades1 »
Logged
Age Quod Agis

Offline gschuld

  • Master
  • *****
  • Posts: 2,346
Re: Suggested timing curve setting for Dyna 2000, 1025cc
« Reply #8 on: June 27, 2021, 12:56:36 PM »
Quote from: Tracksnblades1 on June 27, 2021, 05:15:56 AM
Quote from: gschuld on June 11, 2021, 02:41:27 PM
Ok, next question.  Timing curve for Dyna 2000.

Engine in question:

1025cc for road race application.
CycleX Ported head, 34/28 thin stem valves, beehive springs
New JE 72mm flat top pistons (10.5:1 compression). Great squish band area.
Carrillo rods
MotoGPworks 4/2/1 exhaust
New Keihin CR-31s with 29mm restrictor rings (AHRMA class restriction)

Dyna 2000 ignition with Dyna S pickup
Megacycle 125-75 cam
CycleX ProCut modified (backcut 2/3/4 etc) complete F Model trans

I recall #4 (of 5) being a popular choice, Paul in Australia races a 915cc l/CR-31s road race engine at the #3 setting.

Any thoughts on initial setup is welcome.

As always, thanks in advance

George

What length rods did you go with..?
Do you have any Dyno time in..?

Dyno time turned into a disappointing debacle with no results to show for it

Standard length Carrillos.
Logged
Pages: [1]   Go Up
« previous next »