Topic: Dad's 1978 Honda CB550k

[joegeis]

Looking good!

Is that oil JASO MA2 rated?

If not, you may have a slipping clutch.

No, its actually not. I bought it a while ago, and for the life of me I can't remember why I picked this one.

That said, I went with it for now. I got the exhaust back on and fired it up! It started on the first crank with the choke on, and idled pretty evenly shortly after. I took a couple of videos, and I do hear some unusual engine noise that I'm hoping you guys can help me with.

Videos at the bottom:
https://photos.app.goo.gl/76NLUK6LhMfKbXkt9

[HondaMan]

It sounds like the cam chain is a little bit loose?
Maybe try this: remove the #4 intake valve's tappet cover (and the points cover) and slowly turn the engine (forward) at the points' nut until the intake valve starts going down, then about 15-30 degrees more. Right there, release the nut of the cam chain's tensioner, and you might have to wiggle the slotted screw a few degrees side-to-side (in case it's stuck). This releases the spring tensioner against the tensioner bow, and the slack of the chain will be on the back side right then. Then snug the nut back down & see if it helped?

How close to perfect is the ignition timing? It should be dead-on both of the "F" marks at engine speeds below 1200 RPM.

[joegeis]

Good points! I did not set ignition timing after the rebuild, so that is likely not perfect.

I tried to set cam chain tension, though I always feel like it doesn't actually do anything. The adjustment bolt always wants to turn with the locknut when I try and tighten it. I'll need to spend more time monkeying with this I think.

[scottly]

I tried to set cam chain tension, though I always feel like it doesn't actually do anything.

It never does. Don't force anything or fix it until it's broke.

[joegeis]

I figured out that horrible sound tonight. I was missing a washer on the cam chain tensioner, so I was not able to get the nut tight. Whenever I tried to tighten it, all I was doing was turning the adjustment bolt the wrong way. I figured it out, added the missing washer, adjusted the cam chain and tightened it all down, and it sounds so much better now!

I decided to push my luck right before coming in for the evening, and got the timing strobe light out and hooked up to cylinder 1. With engine idling at about 1400 rpm, the dash mark was lining up over the "F" on "TF 1.4." WAY further out from the dash line for "T." I have Hondaman's transistorized ignition, if that effects timing. I don't have a reason for thinking that my timing is incorrect, just thought it prudent after the rebuild and before syncing the carbs (tomorrow's job).

Once that's done, I think its time to throw the tank on and go for a test ride

[denward17]

Did you check 2-3 ?

[joegeis]

I did not check 2-3 yet. I actually decided to just throw the seat on and take the test ride I had been dying for! Got around the block and the bike died before I realized I forgot to open the petcock! That was a scare

When I went out today to take it for a little longer ride, the #3 carb was leaking fuel. I gave it a rap with the screwdriver and couldn't get it to stop, so I tore the carbs out again. I've inspected the floats and the float valve. There was no debris in there and nothing bound up. I blew everything out with compressed air. I'm not really sure what else it could have been. I have not had overflow/leaking problems before. Tomorrow I'll hook it up to my aux tank and see if it starts overflowing again before I start the painful process of reinstalling the carbs. I'll report back if it's leaking still.

Other things:
1. I tried syncing the carbs with vacuum gauges (before I was having my leaking problem). I admittedly have no damn clue how to do this properly. I chased them around and around and think I only made it worse. It seems like nothing I do can change the reading on carb 4, only cause the others to increase dramatically and rev the bike up. I put it back to how it was when I started. I did confirm that my idle mix screws were all set to 1.5 turns out before starting.

2. Because of my sync issues, I think I should return to my timing issues first. Another area I feel woefully ignorant. I have Hondaman's transistor ignition, so I don't think I can do static timing anymore, right? I was getting no light when trying that way. I do have a dynamic strobe gun, but the index line seemed way out in front of where it should be on 1-4. Again, I'll try to get some pictures of it next time.

I'm taking the Triumph to the track again this Sunday, so that bike needs some love tomorrow!

[joegeis]

Got the carbs back on with no leaks! I took it for a 10 min test ride around the neighborhood. It's feeling really good now. I have a few things to work on still, but its definitely rideable now. If you look closely, you can see me almost forget to turn the petcock on again!

To Do List:
* Fix hanging Idle (timing, tuning?)
* Replace missing nuts for the speedo and tach
* Fix/replace misreading tach
* Replace petcock and get rid of in line fuel filter (ordered)
* Replace fenders and tail light (someday).

Pretty short list considering how far we've come! Okay, time to start track prepping the Street Tiple!

[scottly]

With engine idling at about 1400 rpm, the dash mark was lining up over the "F" on "TF 1.4."

That's where it's supposed to be, at the F mark: F for fire. The T is for Top Dead Center.

[joegeis]

With engine idling at about 1400 rpm, the dash mark was lining up over the "F" on "TF 1.4."

That's where it's supposed to be, at the F mark: F for fire. The T is for Top Dead Center.

I marked in this picture where it lines up. Is this right? Not over that second line, but over the letter F itself.

Also, I just punctured a hole in the oil pan of my Triumph Street Triple while loading it on the trailer for the track tomorrow... Although I won't be racing tomorrow (I'm fresh out of oil pans), at least I have the CB running while the other bike is in the shop for the next week or two!

[grcamna2]

With engine idling at about 1400 rpm, the dash mark was lining up over the "F" on "TF 1.4."

That's where it's supposed to be, at the F mark: F for fire. The T is for Top Dead Center.

I marked in this picture where it lines up. Is this right? Not over that second line, but over the letter F itself.

Also, I just punctured a hole in the oil pan of my Triumph Street Triple while loading it on the trailer for the track tomorrow... Although I won't be racing tomorrow (I'm fresh out of oil pans), at least I have the CB running while the other bike is in the shop for the next week or two!

The engine should fire on the small,stamped line just to the right of the T,which represents the F mark on that particular advance mechanism.
I think you have the bike firing way too advanced if it fires on the red mark

[scottly]

I keep forgetting how close the T and F marks are on a 550 compared to a 400 or 750.

[joegeis]

Okay, uncovered more clues (and problems) this morning. I was trying to work on timing, but I couldn't get the bike to idle below 2k rpm. It would just die. I decided to check exhaust temps using an IR thermometer. 1-3 were 160 degrees. #4 was 90 degrees. #4 isn't firing. I tested resistance at the coils and between the 1-4 spark plug wires, and they look good. So I tested for spark with all 4 wires using the plug from #4. All wires gave strong spark, except #4. I got only a little orange spark and usually only when first pressing or while releasing the start button. If the coils, wires and caps are all new, and resistance is good, what else could be causing this issue?

Background:
New Coils PartsNmore 17-6823
New Caps PartsnMore 23-3119
Hondaman Transistorized Ignition
Two year old battery, but always kept on a tender

Its starting to feel like my gremlins are electrical and not air/fuel. Also, not sure if this is normal, but when trying to set the timing, I noticed sparks between metal parts under the points cover. You can see them in at the beginning of the video at the bottom of this album.

I'm going to let the battery juice up for a bit, then maybe try removing the transistorized ignition, or even putting the original coils back on the bike. I'm not really sure where to go from here...

[scottly]

What does the #4 spark plug look like?

[joegeis]

What does the #4 spark plug look like?

brand new - only a few miles on it.

[scottly]

I would try putting the old 1-4 coil back on and see if that helps.

[denward17]

Looking at the video, its hard to tell, but are the green/yellow wires connection point touching the base of the points plate?

I saw the sparks near the wires....is it grounding out?

[joegeis]

So I think maybe I've started going down too many paths.

I tested voltage on the black/white wire going to the coils and it was only 10.45 V. I hooked up to the tender and I'm charging the battery. I've been doing a lot of testing and idling, so the battery may need a charge.

I also unplugged the transistorized ignition system and plugged the points back into the coils directly. I'm getting spark at #4 now (but I didn't retest after charging the battery back up before taking off the transistorized ignition!) THEN, I ran the carbs dry (did not hook up a fuel source), so inconclusive test.

So, I'm going to take a lunch break, let the battery charge, hook up my aux fuel tank, and then test #4 for spark, and then try to get it idling properly, then try to set timing off the points, then plug the transistorized ignition back in and see if it is still all working.

I went through every connector on this bike and cleaned/lubed them up two years ago, though I think I've always been dealing with resistance through the old harness. If none of this gets it running just right, is my next step a new harness?

[BenelliSEI]

Maybe a new battery first?

[joegeis]

I'm moving this troubleshooting over to a new thread in the normal forum: http://forums.sohc4.net/index.php/topic,205739.0.html