Topic: CB550 - CR29s is this the best it gets? Will CR26s be better street carbs?

[akabek]

I used some heavy plastic ties.  Where did you buy plastic clamps?  Can they be reused?

I did find a brand new OEM advance mechanism on ebay last night they wanted $170.  I will try the mod tonight and if it does not work I will buy another one off ebay to try.

I agree the wiring is light gauge that runs to the coils.  If I bypass the harness wire and run power from the kill switch to the coils do I still need the relay?  I will see if I can find a wiring diagram somewhere.

My kill switch is still the original.  I wonder if I should upgrade the controls to something current.  I just wanted to keep the vintage look....

[akabek]

Great article on how to get full power to your coils:

http://www.wgcarbs.com/index.php/using-joomla/extensions/components/content-component/article-categories/89-coils

[FunJimmy]

I'm puzzled by the swing from very lean slow (pilot) jet to rich needles that your tuner settled on.
Most CR's have found the YY8 needles pretty good, rich at time, but YY5's are unheard of.
Do you have any dyno graphs to share?

[akabek]

I'm puzzled by the swing from very lean slow (pilot) jet to rich needles that your tuner settled on.
Most CR's have found the YY8 needles pretty good, rich at time, but YY5's are unheard of.
Do you have any dyno graphs to share?

Jimmy, I just put that in there to wake you up.  LOL  I will double check the needle size as I am sure that is what he told me when I asked about the jetting.  He jetted the bike with unfiltered stacks but I would never have guessed to use YY5s.  I still need to take the bike out for ride to see how the new jetting feels.  Hopefully the road are dry tonight after I do the spring mod.

He did give me a dyno chart but with my electrical and advance issues I did not pay much attention to it.  I will post in up in the next couple of days but the bike was cutting out around 7K RPM.

[akabek]

Jetting: 105 mains, 50 pilots and YY5 needles (clip level unknown) open stacks.  I can confirm they used YY5 needles

I did the advance spring mod and now the bike will redline   I took the bike out for a little spin and when accelerating from a stop it pulls hard to red line.  If I am cruising and try to go WOT depending on the RPM is it slow to accelerate.  A work around is to drop a gear.  I did my test run with open stacks but I prefer to install my foam socks.  My work order suggests once the advance is working to drop the mains down to 102.  Before I do that I will clean, oil and reinstall my filters.  They also suggested dropping the pilots down to 45/40.  I have what I need to run 12v with a relay to my coils so that is on my list of to dos.

This is a copy of my dyno run.

[akabek]

I am getting ready to do the battery to coil modification using a relay and I need and double check how I will include the Pamco electronic ignition.  These are the instructions for the Pamco unit:

1. Connect the red wires from both cables of the PAMCO  by extension to the Black / white wire from the kill switch

2. The black wire from both cables of the PAMCO is connected to the frame.

3. The green wire from one of the cables is connected to the 1 - 4 coil. (blue wire) located in the vicinity of the rear brake light switch connections.

4. The green wire from the other cable is connected to the 2 - 3 coil (yellow wire) located in the vicinity of the rear brake light switch connections.

Below is the diagram for the modification.  Do I leave the green wires alone and connect the two red wires from the pamco unit to the power (to coils) wire?

[FunJimmy]

Do I leave the green wires alone and connect the two red wires from the pamco unit to the power (to coils) wire?

Yes. The green wires remain as stated in the Pamco instructions. Those are the triggers.
Alternatively, you could connect the red wires to another source of switched battery.
Red is power supply to the Pamco unit.

[akabek]

I took another look at the wiring diagram and sorted it out.  The battery to coil mod is done....now the bike starts immediately.  I will put the filters back on and take a good ride to see how thinks are running.

[akabek]

When I received the bike back from the Dyno run they had the jetting at: 105 mains, 50 pilots and YY5 needles 3rd position from the top and open stacks.  I did the advance spring mod and ran power direct from the battery to the coils to correct my electrical issues.  They shop suggested dropping my jets down a step of two after my electrical was corrected.

I reinstalled my ITG socks and made sure they were positioned near the bell of the stacks so the air intakes were not blocked.  I change my mains from 105 to 102s.  When i dropped my pilots I found the low end hesitated with the sock filters back on so put the pilots back to 50. 

My current jetting is: 102 mains, 50 pilots and YY5 needles 3rd position from the top
I went for a 200KM ride on saturday and what I found is from a stopped position when I wind out the bike it is flauless and pulls hard.  If i am cruising at 4,000-4,500 RPM and hit WOT the bike bogs.  If I drop a gear when cruising at this RPM and hit WOT it puts me in a higher RPM so the bike accelerates quickly.  With this jetting my wife told me I blow a little smoke (rich) at the start when I wind the bike out from a stopped position.   I am not sure if it would get any better than my current jetting??

Something I find odd with my clutch is when the bike warm up it does not want to go into 1st gear.  Sometimes if I gear up to 3rd I can then drop down to 2nd and 1st.  Hopefully some adjustment will correct this but does this seem odd?

[akabek]

Something I find odd with my clutch is when the bike warm up it does not want to go into 1st gear.  Sometimes if I gear up to 3rd I can then drop down to 2nd and 1st.  Hopefully some adjustment will correct this but does this seem odd?

What is a good oil for me to use?  I am wondering if the Dyno killed my oil causing me issues changing gears...

[bwaller]

The dyno wouldn't be any different than hard pulls on the street. You might adjust the clutch, it may be dragging slightly and if the idle is a tad high it might make it tougher to shift. Finding 1st isn't usually a problem although it might not mesh smoothly. I won't comment on oil, just choose a quality brand.

[akabek]

The dyno wouldn't be any different than hard pulls on the street. You might adjust the clutch, it may be dragging slightly and if the idle is a tad high it might make it tougher to shift. Finding 1st isn't usually a problem although it might not mesh smoothly. I won't comment on oil, just choose a quality brand.

I will adjust a clutch a little more.  I just seems odd their are no issues when the bike is cool and 1st gear goes into hiding after the bike warms up. 

As for oil I still have some Motul 5100 and Motul 300 from the track bike I had.  Are there any issues using up this oil while I have some available?

[FunJimmy]

As for oil I still have some Motul 5100 and Motul 300 from the track bike I had.  Are there any issues using up this oil while I have some available?

Both are great. I've used 5100 before and really like it.

[akabek]

As for oil I still have some Motul 5100 and Motul 300 from the track bike I had.  Are there any issues using up this oil while I have some available?

Both are great. I've used 5100 before and really like it.

Did you use it on your CB550?  I have it so I should use it up if I can.

[FunJimmy]

Did you use it on your CB550?  I have it so I should use it up if I can.

Yup, and I'll probably go back to it because it's available everywhere.

[akabek]

I have been making further adjustments to the jetting to clean up my low RPM hesitation and I landed on the following jetting:

102 mains, 70 pilots and YY6 needles 5th position from the top

With this jetting the bike accelerates hard right through each gear and when cruising below 5K RPM the bike will not hesitate when I open the throttle quickly.  My test ride was for around 8-10 kms and what I found odd is after my ride I pulled a couple of plugs and there was no change in color but behind the pipe was carbon which would indicate a rich setup.  I also noticed while coasting to a stop and the throttle closed their was a spitting sound maybe from the carb.   Any thoughts?

[FunJimmy]

How about the air screws?

[akabek]

Refresh my memory.  If I am using resistor plug caps should I be using resistor spark plugs no non resistor plugs?

[FunJimmy]

Refresh my memory.  If I am using resistor plug caps should I be using resistor spark plugs no non resistor plugs?

If you're using resistor plugs with resistor caps the ohms resistance is the sum of both.
i.e.: 5k ohm resistor plugs + 5k ohm resistor caps = 10k ohms resistance = coils work harder.

[turboguzzi]

i use resistor caps + resistor plugs and works great for me, had problems when running NON resistance.
FJ, coils work harder is a bit sounds a bit negative and misleading IMHO
overall higher resistance manifests itself as a longer spark which is good to tackle a wider mixture range.the only trade off is that you should stay on the lower side of spark plug gap range.

[akabek]

I have not posted here in a while but I thought I would offer an update.  A couple of days ago I decided to remove my filtered stacks and install K&N pods on my CR26 carbs.  I adjusted my jetting to the following: Main 105, pilot 65, needle YY7 5th position, Air jet 220 and mix screw 1 turn out.  This is probably the strongest acceleration I have experienced to date.  The bike still bogs if I open the throttle while cruising below 5000 RPM but it runs much better now. 

A new issue I am experiencing are multiple hesitations in 3rd gear.  I have a thread and a video on this is anyone can offer assistance.

http://forums.sohc4.net/index.php/topic,148658.msg1696065.html#msg1696065

[akabek]

I figured it is time to close out this thread.  My third gear issue turned out to be a bent bearing set plate allowing the shaft with the two gear shift forks to move too far to the left sliding it out of 3rd gear.

When I was jetting the carbs I was expecting the system to behave like a modern bike.  These carbs do not have a fuel pump and work off of gravity and vacuum so removing the factory air box really effects the air flow.  With my setup I have to roll on the throttle below 5,000 RPM and above that I can snap WOT without bogging.  This is just the nature of the carbs.

My jetting ended up with the following: 
Main   102
Pilot   60
Needle   YY7 5th position down
Idle Screw     1 turn
Air   220

[FunJimmy]

Very simular results but I don't get bogging below 5K.

My current jetting:

Pilot    60
Idle Screw  1 5/8 turn
Needle      YY8
Clip      #5
Main    102
Air     220

Thinking YY7 needles might be a bit better for midrange.
Will let you know.

[akabek]

I definitely need to watch my throttle control at low RPMs.  Too much and she bogs until I ease up.  I am slightly rich but I need to still need to adjust my mixture screw.  Overall the bike is running well now.

[turboguzzi]

akbek, well, so at the end of a long trial and error you seem to agree that 26 are a better fit for a street 500? I believe some of us  told you this already in the first page of the thread
some throttles have progressive ramps that open slides slower at the beginning, a relatively easy to try mod that might help with bogging.