Topic: My first bike (77 CB550K) and all the joys that come with it.......

[mmtsquid]

OK, so it's not a carb adjustment issue, it's just a fact of life.
I can live with it, just wanted to make sure it wasn't a symptom of something else. (rich/lean)

[Caferacernoc]

Your carbs do not have an accellerator pump. The bike will probably always have a bit of a hesitation when you twist the throttle quickly. On the earlier '70's bikes(pre emissions) they dealt with it by running the bike a little rich at idle and in the midrange(needle clip position). Your bike has fixed clips I believe in the carbs so your kinda stuck. The best you can do is get it tuned the best you can. Syncing the carbs will help in this regard in addition to helping with your idle. Having said that if it won't idle smooth at 1100rpm and you have to keep it at 1600 to avoid the camchain or clutch rattle it won't really hurt anything. Before I got a 750 I spent three years tuning the heck out of a '76 550 with an open set of 4 into 2 pipes and velocity stacks, otherwise stock engine. I tried everything with the carbs and ignition system. When I was done I had it running 105mph and could get 45mpg. It was faster than any other fairly stock cb550 I've ever rode or riden with. However, the idle was poor below 1500rpm still and I had a small hesitation at 3500rpm. That's as good as it got.

[mmtsquid]

OK, so it's not really a demon worth chasing.

What about my backfiring ( i guess popping is more accurate) issue?

[dusterdude]

a pop/poof usually indicates a lean condition

[dusterdude]

is the pop thru the carbs or exhaust,that may change my previous answer

[mmtsquid]

Through the exhaust, specifically on the #1 and #2 cylinder side.
#2 is the cylinder I had trouble with initially (didn't fire at idle).
All air/fuel mix screws are at 1 1/2 turns out.

I know the bike needs a good synch (just to ease my mind if nothing else) but until I buy one or build one, I have to live without a manometer.
Carbs are clean - so if it it is in fact lean, how do I correct this without re-jetting (which I really don't want to do)?

[dusterdude]

yea,that could a misfire of some sort or an exhaust leak too,good luck

[OldSchool_IsCool]

and is the popping on accel, decel, under load, idle, stedy speed....??

[TwoTired]

Do a thorough tuneup and carb synch and let us know if the exhaust popping is still there. 

The head pipe copper gasket can leak and cause poping in the exhaust, too.  Has that been disturbed?

Cheers,

[mmtsquid]

The popping happens at steady speed.

The head pipes and exhaust have not been disturbed since I bought the bike, but I had planned on taking them off to clean the collars.

I am building a vacuum gage this weekend - will synch and report the results.

[mmtsquid]

Well, I got busy and built the vacuum gauge on friday night.
Hooked it up saturday morning, and after messing with the aquarium valves a little bit to reduce jitter in the gauge, I checked all four cylinders and............
It was perfect.  Didn't need to adjust a darn thing!
Good news, I suppose.
took a nice long ride into work this morning (40 miles) - the bike behaves beautifully!
Not sure what the top speed on this baby is, but it rides at 70 very nicely, and theres a lot of tach left over!
The idle is perfect (1100), and the popping that I was complaining about has quit.
I'm VERY happy with this bike!
I repainted the leg guard and rear brake pedal silver (rattlecan), and they turned out pretty nice!
I'll do the rear shocks and luggage rack this evening, then I'm leaving this bike alone until winter (when the cafe build starts!)

Thanks so much for everyone's help - this forum is invaluable!

[OldSchool_IsCool]

Glad it all working!! We'd love to see some pics when/if you get a chance. 

Also, whenever I get an answer from this forum that I find to have saved me much $$ and aggravation, or if someone sends me a part that I can't do without,  I try to donate a little of that saved $$ to the cause.  Look for the "Make Donation" button at the bottom of the front page

http://www.sohc4.us/

No pressure to do so, but try to imagine a world without this forum!!!

[dusterdude]

good deal,glad it worked out for ya

[mmtsquid]

OK, life isn't so rosy anymore........
I was riding home from work, 70 MPH, and the bike just quit - didn't sputter, stall, make funny noises, it just died.
Electrical system DOA.
I check fuses, jiggle wires, etc., and head light comes on, but starter won't budge.  I was able to kickstart it, and took off.
200 yards later, it died again.
This time, nothing would make it come to life.
I disassembled the ignition harness, to see if I could "hotwire" the bike (the ignition switch has been acting a little funny, like having to jiggle the key to get the lights to come on), but no dice.
I'm not an electrical whiz by any stretch, so I'm kind of at a loss!

HELP!!!!!!!!!!!!!!!!!!

[TwoTired]

Get a voltmeter and check the voltage of the battery.

Charge the battery with a separate battery charger.  NEVER reverse the polarity!
Measure and record battery voltage before and after the battery has sat for two hours.
Remove headlight fuse.
Kick start bike, measure and record battery voltage at idle and 1000 RPM increments up to 5000 RPM.
Replace headlight fuse.
Measure and record battery voltage again at idle and 1000 RPM increments up to 5000 RPM.

Report findings.

[mmtsquid]

Can do - I have to go buy a meter, and I will get the info on sunday, and report results.

[hcritz]

Hey MMTSQUID.
Had a similar problem a few weeks ago...turned out to be the ignition switch...the contacts are bradded to the terminals and one of mine had gotten loose. You can only get the the top three easily...but I was able to carefully solder those to make a good connection.
It's not too hard to pull the switch...the electrical connector may be a bit of a pill to get off!

[mmtsquid]

My unexperienced and novice instinct tells me that it is in fact the ignition switch, as you typically had to "jiggle " the key to get the bike to wake up.
Having said that, I'm still going to take this opportunity to become intimately familiar with all of the wiring, as I noticed there is an awful lot of black tape under the left side panel...........

[OldSchool_IsCool]

Squid,

There are wiring diagrams on this site and likely one in your shop manual.  I like to use the interactive diagrams at www.oldmanhonda.com as I can gray out the systems I'm not interested in at the moment.  The diagrams are not 100% 550, but close 'nuf to get a basic understanding.

[mmtsquid]

That interactive diagram is way cool!

Now, since I'm thinking I will need a new ignition switch, where is the best place to find them?

[mmtsquid]

Well, I found the problem....
The "Clips" that hold the fuses in the fuse box....
The one holding the main fuse had corroded and cracked by the solder.  I've fixed it temporarily, but my question is, can I buy replacement clips from somewhere (like Radio Shack) and re-do the whole thing, or should I just buy another fuse panel?