Topic: 1977 CB550 K cafe racer build

[Zaipai]

Joe found this on CycleX's site, not sure if it helps or not but its info non the less..

Reading spark plugs is common knowledge in many publications. They will show you pictures of spark plugs and expect you to duplicate the color as shown. (Thats cool.) Ever notice your plugs never really look the same as the pictures? Here is what we did years ago!!!!! During the tuning process, NGK spark plugs never seemed to show the coco brown color we were after. We would switch to Champion spark plugs for the tuning process. (Oh no, Champions?) Yes, Champion spark plugs show color better and are easier to read. Then of course we switch back to NGKs

Note:
Once again, there are many variables in tuning the internal combustion motor. Even Dynos are not exact at times. This is just a little tip we did years ago and hope this helps you someday!!!!!

.: Scott :.

[traveler]

what would be the benefit of a 8EA plug over a 7EA?  Heat range?

EDIT:  I went to the NGK website.....I got it figured out.  and 8EA is one heat range colder than a 7EA....


~Joe

[Zaipai]

what would be the benefit of a 8EA plug over a 7EA?  Heat range?

EDIT:  I went to the NGK website.....I got it figured out.  and 8EA is one heat range colder than a 7EA....

~Joe

Yea, I switched and it made a big difference.. I did that on the advice of Hondaman.. Worked like a charm. I believe I went to 7EA..

.: Scott :.

[traveler]

Well....here is what I have found out....so far from two guys on here, who are running pretty similar setups to what I have:

"edbikerii's" setup:

MAC 4-1
Emgo pods oiled with Uni filter oil [see below]
PD46C "lean burn" carbs
105 Keihin mains
stock E2349F needles in 2nd position from top (2nd leanest -- stock position!)
42 pilot jets (stock)
Idle Mixture Screws 2.5 turns out
float height ~14mm
67A Throttle valves (stock) [EDIT: added 8/16/07]
NGK D7EA spark plugs w/about 4,000 miles - stock gap.
Dyna S Ignition
Dyna 5 Ohm coils and wires (with non-resistor caps)
Timed statically to stock advance per Dyna S instructions
87 octane gasoline (with up to 10% ethanol warning on pump)
My elevation is about 200 ft. above sea level.

And then Shoemaniii's setup:

"my 77cb550k w/pd46a carbs, pods and oem 4/4 "hit the wall" at about 6000rpms, i lowered the clip position and it now screams to 8000rpm (haven't dared to run my pride to redline, although she pulls to 85/90mph easily).  strong power everywhere, no popping on decel, etc.  here's my set-up, 0-2000ft el."
pd46a carbs
pods w/oem 4/4
mains -- 105
idle jets -- 42
clip position -- 4th down
a/s -- 2t
needle -- e2350f
floats -- 14.5mm
ngk 5ohm caps
relative compression, cold--150, 155, 160 and 150psi


Looks like more turns out on the air needles resutls in raising the needle.....

So, in short....I am going to pull the carbs....check and reset my valves, cam chain tension, and point gap, and then install the 105 mains I ordered and set my floats at 14.5mm instead of 12.5mm.  If she acts lean at all....then I will raise the needles and bench sync.....and make sure those air needles are the same!!!!  It some point, it will run good....then I will sync the carbs with a vacuum setup.  Still up in the air as to whether to go with a dyna ignition or Hondaman.  I HATE the idea of buying new coils, wires, etc., when the stock stuff is working just fine....I'd rather make what Honda made work for me.

I really wish i would have left the all the engine stuff stock....it worked perfectly that way....But I gutted the bike, so now I have to get it back to where she is liveable, and still looks cool and is ULTRA light (she is already VERY light!~ )

~Joe

[Zaipai]

Sounds like a good plan. Don't forget the stock stuff works, however only with ALL the stock stuff.. Trying to make it work is much like sticking a round peg in a square hole... Just let me know if/when you need the sync guages..

GL

.: Scott :.

[traveler]

Okay....jets arrived, and I pulled the carbs tonight and got everything together.

This weekend, I'll see if I can make some forward progress or not.

I'm planning on adjusting the valves and cam chain....check the point gap and then hit the carbs.

I will raise the needles, bench sync, adjust the air needles, install the 105 mains and see how she works!

~Joe

[Zaipai]

I bet she runs like the devil..

.: Scott :.

[traveler]

....well that would be okay....

[traveler]

Started today by adjusting my valves.  Whoever designed this deal, must have had hands the size of a 5 year old.....VERY cramped!  10mm wrench, flat bade screwdriver and some feeler gauges.  I marked off a sheet of pepar as I finished a cylinder.







Then I adjusted the cam chain tension.....too easy, used the kicker to turn the motor over until both valves on #1 cylinder were closed, and then broke the nut loose.  I heard it "click".  Then, I turned the adjuster with a screwdriver and could feel the spring tenshion, so I ensured that it wasn't bound up, and the tension is good....tightened the bolt up and moved on.

Dropped in my 105 main jets, set the floats at 14-15mm, and then raised the needles 2 notches.  Turned the air screws out 2.5 turns and tried to start it.  Bike wouldn't run!  Turned the air screws in to factory setting of 1.5 turns out.....no change.  Pulled the carbs, and lowered the needles 1 notch.  Now, they are one up from stock.  Engine tries to run but won't unless I keep the throttle pinned back.

Seems to mean the carbs are fighting to get fuel....maybe too lean?  I tried to start it with starting fluid...no change.

So....Since the floats were working okay earlier, and I moved them OUT to 14-15mm, I will put them at 13mm, basically where they were, and see if the fuel level in the bowls is just too low....hopefully, that will get the fuel through the jets.  After that, I might have to go larger on the jets.  The last time the bike acted like this, the mains were too small.

So right now, I'm at:

PD46a carbs
Air=1.5 turns out
needle E2350 on 3rd clip down (2nd down was stock)
105 mains
42 pilot

Any ideas would be GREATLY appreciated!

~Joe

[Zaipai]

Wow, I have no idea. All I can figure is that it has some thing to do with the mains.. I just don't know much about carbs.. Seems to me that its starving for fuel.. I really hope some one comes up with the answer..

.: Scott :.

[traveler]

thanks, Scott.

I'm going to drop in my 115 mains in first, and see what happens.  If it is still starving, then the floats have to be re-adjusted.

This morning, I've seen two NICE CB's on here that guys cut the back half of the frame off and hardtailed....almost brought a tear to my eye!

~Joe

[Zaipai]

Yea. I am with you on that. Tho they can look good that way, its only the really butchered bikes I don't mind seeing that happen to because they are likely never going to see a restoration and at least this way they get back on the road. However nice bikes that get the hard treatment make me weep..

GL with the carbs, I have faith you will get it eventually.

.: Scott :.

[traveler]

Well, having spent the better part of the weekend on the racer, I found out that my bike, at this elevation, and the way my engine sits, i.e. compression in each cylinder, etc.  That it likes the needles ont he 2nd (stock) notch.  To get the bike running pretty good, I had to set her up as this:

105 mains
needles=2nd clip down (stock setting)
A/S 1/2 turn out (stock is 1.5 turns!!!)
Floats=14.5 mm
EMGO 35mm pod filters
4-2 exhasut system with baffles
NGK 7EA plugs

Even then, It idled ROUGH and was really shaking.  I had done a bench sync, but something was amiss.  I let it idle like that for a few minutes then shut it down and did a plug chop.

1=rich
2=lean
3=good
4=good


Now, since this was at idle, and I figured out on these PD46a carbs that turns out=rich, and thus turns in=lean, I turned the airscrew on #1 IN 1/4 turn, and turned the airscrew on #2 OUT 1/4 turn.  Then restarted the bike.  VERY smooth idle, crisp throttle!

#1 Airscrew is at 1/4 turn out!!! but it WORKS!!!

Now, apparently this is due to the unique circumstances that each cylinder finds itself in....i.e. compression, air available, as one carb is inboard and one is outboard, so available airflow is different.

Now, on to the ride....NO POPPING, so it isn't lean, but the bike really feels sluggish and bogs a tad.....so what I need to do now is:

1.  Vacuum sync carbs
2.  Be prepared to LEAN out the mains. (103,102,etc.)

Crazy huh?  I guess I am at a higher elevation than the guys using 105's....but for whatever reason, my bike is acting the way it is.

anyway no pics this time.....but just wanted to offer an update to any who may be interested.

cheers,

~Joe

[Zaipai]

A man with a plan, gotta like that. Sounds like it should work. I believe you are correct about the elevation.. Don't discount that!

.: Scott :.

[Flying J]

Do a wot plug chop and see how your plugs looks. That will give you a pretty solid idea where your at.

[Zaipai]

When you guys say Plug Chop, you mean take the plugs out and inspect them correct?

.: Scott :.

[MCRider]

When you guys say Plug Chop, you mean take the plugs out and inspect them correct?

.: Scott :.

YEs but more technically I think... run it up to the point where it is misbehaving and "chop" the engine, hit the kill switch and coast to a stop. Then pull the plugs for a reading.

"wot" in this case being wide open throttle.

[traveler]

yeah....I'm trying to take it easy and not get so frustrated......truth be told I HATE carburetors....I am a EFI guy.  I like having a computer that takes samples and makes correction every millisecond....you are always in tune....

Just had to get it back to where it would ACTUALLY RUN and could actually RIDE IT!

Now I will do a vacuum sync, then fine tune the jets via plug chops and trial and error.....BUt I tried different needle settings, and they jsut jsut don't work ON THIS BIKE for some reason.

Thanks for the responses, as always.

~Joe

[Zaipai]

Well don't get all up on the EFI train.. My brother just got a 2008 Yamaha R6 an less then 500 miles out and the EFI is screwing up to the point it wont run right. He took it in because he did not have the software to hook his laptop upto it and work on it. They wanted a gross amount of money to fix it. So he spent 300 to get the software and he is having issues getting the on board computer to spit out results.. Talk about frustrating.. The point is, no matter what you have it can be VERY frustrating..

Thanks for the info guys on the plug chop now I don't feel so inadequate.   

.: Scott :.

[traveler]

hmmmm....my harley EFI is PERFECT.

~Joe

[Zaipai]

hmmmm....my harley EFI is PERFECT.

~Joe

Yep so is our next door nighbours and the guy down the street (6 HD's all together) however the guy behind me is having issues and suspects EFI, I don't know if that's it and I don't know if he knows for sure.. However if it is, I bet he is thinking give me crabs.. See its all about what you have to deal with at the time.. Fact is carbs work great, once you have them working.. I could not work on an EFI  I can on these carbs tho..

.: Scott :.

[traveler]

who would want crabs?

~Joe

[traveler]

Ordered some 102 main jets yesterday, and Zaipai has been kind enough to mail me his vacuum syncronizer on loan to help get this thing DONE!

Thanks again, Scott.

~Joe

[traveler]

What do you guys think about a Ducati 900SS fairing?  The Tank Shop in Scotland makes them in aluminum....

Just a thought....opinions?

~Joe

[Laminar]

Started today by adjusting my valves.  Whoever designed this deal, must have had hands the size of a 5 year old.....VERY cramped!  10mm wrench, flat bade screwdriver and some feeler gauges.  I marked off a sheet of pepar as I finished a cylinder.

The Honda manual's method would save you some time: