« previous next »
Pages: [1]   Go Down

Author Topic: IMS tuning  (Read 510 times)

0 Members and 1 Guest are viewing this topic.

Offline 550Resto

  • Enthusiast
  • **
  • Posts: 189
IMS tuning
« on: August 06, 2016, 05:44:07 AM »
Hello all, I had a question regarding my 78 550 PDC carbs. I've seen talk of adjusting the IMS screws at idle to achieve the highest idle and was hoping someone could explain this procedure and why it's done if the stock setting is 1.5 turns out? TIA
Logged

Offline FunJimmy

  • Who you calling
  • Old Timer
  • ******
  • Posts: 3,802
  • Vancouver
Re: IMS tuning
« Reply #1 on: August 06, 2016, 07:16:51 AM »
While the manual may state that stock tuning is 1.5 turns out every bike is different. Especially a 35+ year old bike. Wear and tear, state of tune, condition of carbs all have an effect.
Logged
You never see a motorcycle parked outside of a psychiatrist's office!

CB550 Cafe Interceptor a Gentlemans Roadster
http://forums.sohc4.net/index.php?topic=27159.0

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: IMS tuning
« Reply #2 on: August 06, 2016, 08:03:05 AM »
Adjust your IMS with the goal of acheiving correct plug color, not idle.
Everyones ears hears differently, and you cant 'hear' proper air/mixture.  Going by idle is inacurate.
do an idle plug chop with new plugs, and adjust each IMS as needed based on plug color.
Logged
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"
Pages: [1]   Go Up
« previous next »