Author Topic: Carb Setting with photos,help  (Read 1577 times)

0 Members and 1 Guest are viewing this topic.

Offline Garryk

  • Full Member
  • *
  • Posts: 42
Carb Setting with photos,help
« on: April 21, 2013, 06:23:03 AM »
Took my petrol tank off today to start some tuning and notice my carbs seem to be set different,NO3 and NO4 carbs seems to be set correct but my NO1 and NO2 carbs screw at top seem to be way to high,or maybe there would be a reason to set them like this,or should I reset NO1 and No2 carbs to match NO3 and NO4.
Garryk

Offline Eddie

  • Enthusiast
  • **
  • Posts: 237
Re: Carb Setting with photos,help
« Reply #1 on: April 21, 2013, 06:27:49 AM »
I think I would first do a compression check, if 1 & 2 are way off from the others it could be why the carb sync is off.. Also I'd check the valve lash..

Offline Harsh

  • Expert
  • ****
  • Posts: 1,103
  • 74 CB750 and two 72 CB350's
Re: Carb Setting with photos,help
« Reply #2 on: April 21, 2013, 07:04:40 AM »
A slight difference in height is probably OK due to syncronizing.  However, I would have to say that being that far off is not correct.  I agree with checking the valve lash, but a bench sync needs to be performed.  I bet you will find that the 1&2 slides don't come anywhere near to closing all the way.

Offline harisuluv

  • Master
  • *****
  • Posts: 2,009
Re: Carb Setting with photos,help
« Reply #3 on: April 21, 2013, 08:08:35 AM »
Sometimes people sync them without the idle adjust screw in the correct position. Check your range of motion, it might not even be touching the stop or all the way in.

If both one and two are like that the fork lifters might be off. They usually have keys that prevent them from moving but I have seen the, taken apart and missing.

Offline Garryk

  • Full Member
  • *
  • Posts: 42
Re: Carb Setting with photos,help
« Reply #4 on: April 21, 2013, 11:09:31 AM »
Im was going to do a sync on the carbs next weekend with the proper sync tool,im just not sure now what to do with the no1 and no2 carb set like this,should I set them back to normal and try the sync,or sync the carbs as they are,what is the setting for the idle screw when doing a sync test.
Looks like I need a compression tester now also,and was wonder what size of connector do I need to fit the plug hole.
Not really sure of all these technical words above and fully confused what to do,my guess is i'll make it worse when bike seems to riding ok,
Thanks everyone for your help
Respects
Garryk

PS: The clock says there is only 14,000 miles on this bike and I was told these were genuine miles.
« Last Edit: April 21, 2013, 11:16:41 AM by Garryk »

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: Carb Setting with photos,help
« Reply #5 on: April 21, 2013, 08:00:16 PM »
Set all to match carb 4 picture above, and complete a bench sync.
Please also complete all other maintenance items before finishing with the vacuum sync.
« Last Edit: April 21, 2013, 08:02:01 PM by flybox1 »
'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…"

Offline Tews19

  • I am no
  • Really Old Timer ...
  • *******
  • Posts: 6,465
Re: Carb Setting with photos,help
« Reply #6 on: April 21, 2013, 08:02:12 PM »
Great looking bike. Love how you have it in the house!


I think i read you want 1.5 threads showing for a bench sync??? I may be wrong but i did it today on my 74.. She ran but now the points need to be gapped and timing set.
« Last Edit: April 21, 2013, 08:04:13 PM by Tews19 »
1969 Honda CB750... Basket case
1970 Honda CB750 survivor.

Offline Garryk

  • Full Member
  • *
  • Posts: 42
Re: Carb Setting with photos,help
« Reply #7 on: April 22, 2013, 01:48:44 AM »
All your advice has been taken in, hoping to get a bench Sync done through the week, I read bench sync is done with a 1/16" drill bit placed under each float,will be out today so hoping to get the drill bit, then buy a strobe and some other tools needed to do maintenance, bought this bike to ride and now I seems im just  working on it and the summers here, crapppppp.
Thanks all for your herlp.
Garryk

ps: reading stuff above like valve lash etc,this kind of work is just way to difficult as I don't have the knowledge or tools to carry out this kind of work,,been riding bikes nearly 40 years and ive been lucky buying bikes trhat didn't need much work done on them,now I have the CB750 looks like I bought trouble.

Offline Tews19

  • I am no
  • Really Old Timer ...
  • *******
  • Posts: 6,465
Re: Carb Setting with photos,help
« Reply #8 on: April 22, 2013, 05:51:17 AM »
I'm in your boat. I bought my first cb a few years ago and was afraid to remove The tank. The carbs are really easy. Valve adjustment is even easier.
1969 Honda CB750... Basket case
1970 Honda CB750 survivor.

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: Carb Setting with photos,help
« Reply #9 on: April 22, 2013, 11:12:56 AM »
this kind of work is just way to difficult as I don't have the knowledge or tools to carry out this kind of work,,
wrong!   ;D
tools can be had for less than what you'd pay to have some hack work on a bike older than he is.
you wont know (and probably neither would he) if he got it right.
he'd be looking in a shop manual for direction just as you would.
but here's the best part....he doesnt have the collective knowledge of the forum!

pay a tech to do the service stuff.  you'd probably still not like the way the bike performed after he worked on it, be pissed and finally give in and do reading and working on the bike yourself with our help.

just trying to prevent the inevitable, Garryk, and fewer bills in your pocket  ;)

do the work yourself.  we'll help ya!
better for you.  better for your bike.


'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…"

Offline Tews19

  • I am no
  • Really Old Timer ...
  • *******
  • Posts: 6,465
Re: Carb Setting with photos,help
« Reply #10 on: April 22, 2013, 11:46:30 AM »
this kind of work is just way to difficult as I don't have the knowledge or tools to carry out this kind of work,,
wrong!   ;D
tools can be had for less than what you'd pay to have some hack work on a bike older than he is.
you wont know (and probably neither would he) if he got it right.
he'd be looking in a shop manual for direction just as you would.
but here's the best part....he doesnt have the collective knowledge of the forum!

pay a tech to do the service stuff.  you'd probably still not like the way the bike performed after he worked on it, be pissed and finally give in and do reading and working on the bike yourself with our help.

just trying to prevent the inevitable, Garryk, and fewer bills in your pocket  ;)

do the work yourself.  we'll help ya!
better for you.  better for your bike.

Plus 1000

This coming from a me; I paid someone 400 plus bucks to clean my carbs on my first 550. End product was that I had to send it back several times. I ended up doing it myself. I should have listened to the members here.

On the next 550 I got I did it myself. Had guidance from the members here and it was a great runner.

Plus you won't have to call a shop every week asking when it will get done. I had my bike at a shop for 3 weeks. Finally pulle the plug and took it out and did all the work myself.
1969 Honda CB750... Basket case
1970 Honda CB750 survivor.

Offline iron_worker

  • Master
  • *****
  • Posts: 2,081
Re: Carb Setting with photos,help
« Reply #11 on: April 22, 2013, 11:48:53 AM »
All your advice has been taken in, hoping to get a bench Sync done through the week, I read bench sync is done with a 1/16" drill bit placed under each float ...

The idea is to place the drill bit under the slides, not the floats.

IW

Offline Garryk

  • Full Member
  • *
  • Posts: 42
Re: Carb Setting with photos,help
« Reply #12 on: April 22, 2013, 03:52:05 PM »
I did mean to say slides, my mistake :).
Well got the carb cleaned and slides all adjusted to their proper setting,also the floats were way to low so set them higher 26mm as stated on this forum, hoping to get carbs fitted back on tomorrow, wont be able to road test her till the weekend.
Thanks everyone for your help, respects to you all.
Garryk

ps: will keep you updated