Topic: CB550 - Wont idle, cold cylinder (or start anymore)

[JoshuaJames]

knowledge is power! more stats

bought a new fancy multimeter. checked the caps resistance

1 - 0 ohms
2 - 4.86 ohms
3 - 5.25 ohms
4 - 4.91 ohms

cylinder one was the cold cylinder as well. it has fired up since then, but not consistently. hoping this is at least part of the problem. i will be replacing the one cap, but are the others all within an acceptable range?

[JoshuaJames]

after much trouble shooting, it appears as if i have made SOME progress, but still no idle.

watch video.. hangs out at around 3,000 rpm, but still dies unless i am playing with the throttle.

IMG 1137 MOV

[iron_worker]

Get a proper airbox and clean your idle jets again.

IW

[JoshuaJames]

will do on the idle jets. thanks!

with regards to the airbox, what do you mean by "proper" ? i have the honda stock airbox.

[rb550four]

JJ,
  I'm guessing that you fixed the plug cap problem. How did you overcome the timing issue?

[TwoTired]

How are you feeding gas to the carbs?

[JoshuaJames]

i have an auxiliary "gas tank" set up using a fuel line and old 2 litre pop bottle.

[TwoTired]

Is the bottle higher than the carbs?  Is the bottle vented, allowing air to replace the draining fuel?

The idle/pilot/slow jet tube is higher up in the bowl than the main.  If the carb bowls can't fill correctly, the idle jets starve first and the engine behaves as if it is running out of gas.  You can make it run with a more open throttle since the main and mid fuel supply is at the very bottom of the carb bowl.

[JoshuaJames]

Motorcycle

what now? should i let it idle in the driveway and put some additives in the fuel to help clean the engine?

riding is not an option as this point

[JoshuaJames]

JJ,
  I'm guessing that you fixed the plug cap problem. How did you overcome the timing issue?

for the cap, i ran a resistor plug with the 0 ohms cap, until i can replace it.

for the timing, i disregarded the instructions that came with the dyna, as they were not accurate. Found a few blogs on this issue. Static timed, NOT Advance. New multimeter to check all my voltage, updated some connectors, new plugs, etc.... and she seem to be working. I wont know for sure if the timing is spot on until i can afford a timing strobe light, but for now, this will do.

[72_350_FOUR]

I found this response from another forum member when looking for answers for Dyna timing, I havent had a chance to try it yet, but i hope it works as easy as he says....


{QUOTE}

One thing I have noticed about this and many other forums. Everyone "over thinks" every problem all the time.

Dyna S

Make sure battery is charged, Install rotor on GOOD advancer. ie: must be free to move (advance) and springs must be strong enough to snap back.

Take the plug out of #4 cylinder head location and lay on top cover. Turn on ignition switch rotate engine clockwise until you see spark at tip of number 4 plug. STOP there!

Now, look at marks through the hole on timing plate and see where you are as far as aligning with "F" mark with indicator on engine block.

Keep repeating until you have spark at "F" mark.


YOUR done!

Go ahead and try this...and I will guarantee your bike will run perfectly.

WE won Daytona 7 times and 5 National Championships with a a Dyna S and I have never used a timing light!

Don't try and over engineer these things. WASTE OF TIME (me sorry...no pun indended!)

KOS

PS: if your are not running some awfully high compression ratio, like over 11/ to 1 and are on special fuel or something this will be the ticket.

[72_350_FOUR]

also some good info i found on carb synching when you get to that point, hope this helps,,,,


{QUOTE}

So you need to constantly adjust your idle screw (the large screw with spring on linkage) when you are doing the sync.. When you adjust them the idle will be directly affected. You MUST keep the idle between appr. 800-1300. Letting the idle get too high will negate the adjustments because your carbs will be operating outside of the idle circuit. Adjust one, wait a few seconds for the idle to differ, then adjust idle back up/down to range previously mentioned, then continue with syncing adjustments constantly bringing the idle speed into the appropriate range when necessary.
1. To continue from where you are now, I would go ahead and lean out your mixture screws first at 1/8 turns just until smoking stops.
2. set all nuts on the carbs where you were adjusting during the sync so that 2-3 threads of the screw are showing above the nut.
3. Adjust number #1 carb to #2. Make sure to adjust idle speed after back down/up
4. Adjust #4 carb to the same vacuum as #3 carb. Adjust idle.
5. Adjust #3 to #2. Adjust idle.
Repeat sequence until they are all reading the same vacuum. Adjusting in this sequence will keep you from going in circles since adjusting one will affect the others.
Once you have them synced you can fine tune your idle mixture (rich/lean)

Remember, you must have valves in adjustment, cam chain tensioned and a clean air filter before you sync the carbs. It will do you no good to sync them if this hasn’t been done FIRST

[sxecafe]

How's this thing running now? Did you get the timing resolved? Just got my 550 started and looking to set my Dyna S as well.

[JoshuaJames]

Runs well. Starts smoothly. Still cold cylinder, but that is my idle jet so I am pulling that today. Email me if you have more questions, or want some pics or vids.

[fjm5341]

I’m having same issue, did you get the bike to idle?