Topic: Dad's 1978 Honda CB550k

[joegeis]

I've emailed CMC and Paul. I also posted on Reddit. Maybe an answer will come. In the meantime, I bought that tape on Amazon and will wrap it up.

Next, onto the oil leak. Given that there was no oil leak before I dropped the pan, and I have not replaced any other oil seals, and how profusely this is leaking now, is there anything else it could possibly be that I should replace while I have the oil drained?

[newday777]

Is the oil drain threads cracked from someone over torqured the drain plug? Someone before me cracked my 750 drain threads so it leaked. Thankfully I had another oil pan.

[joegeis]

I'll inspect the drain plug, but it all tightened up nicely with a fresh aluminum crush washer on the last oil change.

[joegeis]

I took care of the oil pan today. A few findings:

1. The aftermarket gasket was seated properly and was not damaged. However, the gasket was barely proud of the channel it rests in on the oil pan. There really wasn't much gasket to "squish" up against the mating surface. I expected the Honda gasket would be thicker.
2. The aftermarket gasket was identical to the NOS Honda gasket. I measured thickness with my calipers and both were 3mm if I remember correctly.
3. The drain plug was fine. I must have been mistaken above and not replace the crush washer when I changed the oil last time, so I replaced it this time. I think the wrong size crush washer had been used previously (or it really spread out from being torqued down), though I am confident this was not leaking.
4. I lightly sanded the mating surfaces of the oil pan and the bottom of the engine to make sure there were no burrs or anything that could interfere. Everything was fine.
5. There was no warping or cracking to the oil pan.
6. I cleaned everything up, put in the NOS Honda gasket and applied a thin coat of Permatex ultrablack on top of the gasket.
7. I hand tightened all the screws, waited an hour and then lightly torqued everything down in a cross-pattern. There was a the smallest bit of seepage of the Permatex in a few places.

Monday I will refill with oil and see if she holds. If I still have an oil leak, it must be coming from somewhere else because everything with the oil pan seems to be at 100%.

[joegeis]

While I had the oil pan off, I peaked up under the skirt and found where that mystery steel tooth came from. Its very hard to make out in the pictures, but circles below I could clearly make out a space that had broken off. I don't think this changes much, just confirms that its going to be a major job to repair eventually.  Better to know than not, I suppose!

[joegeis]

Today I refilled the oil and turned the kickstarter until the oil pressure light went off. There were no immediate leaks, so I put a clean piece of paper underneath and will check for drips in the morning. Fingers crossed the oil leak is solved!

I also took care of the carb/airbox situation (mostly). I unbolted the airbox from the frame in order to allow more free play for the plenum to come forward and align with the carb intake. Wrapping #4 was pretty straightforward, but 2&3 are kind of a mess. It was extremely difficult to get in there with the bulky tape. I was able to reinstall clamps on 3&4 and the connections seems decent. The tape stuck very well to the boots, but not well to the aluminum. I didn't do as good of a job wrapping #2, and couldn't get the clamp back in place. I'll fiddle with it more tomorrow. I may need to start over with the tape on that one to try and make it a little tighter.

Now that I have oil and air, I wanted to try and start it! However, I'm now facing an electrical issue that I'm going to have to chase down. I knew something was wrong because you will remember a few weeks back I was having issues getting the turn signals working after removing the forks and unplugging them. Well the gremlins have spread and now one signal is working, the other actually flashes the brake light, and there is no horn or starter working! I only got so far as to ensure the battery was fully charged and test the ground connection in the headlight housing (which was fine). I am watching the Common Motor series on diagnosing electrical issues and will take a crack at diagnosing later in the week. Hopefully it is an easy solve so I can move on to syncing the carbs and can get the bike out for a test ride.

Also, I have to say how nice it was to move the bike around the garage! It rolls so nicely with new bearings and I actually have a front brake. Amazing!

[joegeis]

Okay guys, need some help! I hope you are still with me.

I tried starting it again today, and the starter would work. The bike started running for ~20 seconds at full choke, and then I could not get it started again without starting fluid. Not sure why its so much harder to start now than it was when I first rebuilt the carb. The battery is fully charged. Maybe its related to the electrical issues I had the other day? I am not sure how to diagnosis a starting issue.

Also, there was a tiny drop of oil leaking from the drain plug, which I had very lightly tightened. I snugged it up. There was no leaking from the oil pan seal!

[denward17]

I can't remember what you did to your carbs, but did you check the float levels? 
Assuming that timing and points are set correctly, it might be fuel related.

[joegeis]

I can't remember what you did to your carbs, but did you check the float levels? 
Assuming that timing and points are set correctly, it might be fuel related.

Floats were previously set at 12.5mm, so that's where I left them. I did replace one set of floats that was "sticking."

[grcamna2]

Okay guys, need some help! I hope you are still with me.

I tried starting it again today, and the starter would work. The bike started running for ~20 seconds at full choke, and then I could not get it started again without starting fluid. Not sure why its so much harder to start now than it was when I first rebuilt the carb. The battery is fully charged. Maybe its related to the electrical issues I had the other day? I am not sure how to diagnosis a starting issue.

Also, there was a tiny drop of oil leaking from the drain plug, which I had very lightly tightened. I snugged it up. There was no leaking from the oil pan seal!

I think you need a fellow sohc4 member from up your way toward N. Illinois to come by and have a look at your 550;that does sound carb. related. Have you made sure your plugs are still clean? The plugs might have gotten fouled;how about the points contacts:clean ?

[joegeis]

Okay guys, need some help! I hope you are still with me.

I tried starting it again today, and the starter would work. The bike started running for ~20 seconds at full choke, and then I could not get it started again without starting fluid. Not sure why its so much harder to start now than it was when I first rebuilt the carb. The battery is fully charged. Maybe its related to the electrical issues I had the other day? I am not sure how to diagnosis a starting issue.

Also, there was a tiny drop of oil leaking from the drain plug, which I had very lightly tightened. I snugged it up. There was no leaking from the oil pan seal!

I think you need a fellow sohc4 member from up your way toward N. Illinois to come by and have a look at your 550;that does sound carb. related. Have you made sure your plugs are still clean? The plugs might have gotten fouled;how about the points contacts:clean ?

Man, that would be great, lol! Anyone Northern Illinois volunteers?

I cleaned and set timing on the points. I was working on sorting out my other electrical issues today and found a problem in the left switch housing causing the weird issues with the lights and horn. I'll also test each plug for spark again (I did this before it ran the first time). I also replaced all the plugs. Everything is still original.

I haven't opened the carbs up again since I rebuilt them, however they did sit with fuel in them for 1-2 months while I was working on the wheels. Could they have gotten gunked up again in that short time?

[denward17]

I would say the bowls are ok after just 2 months, what does your spark plugs look like now?

[joegeis]

Been traveling for work and busy, but finally got back in the garage this evening.

* Turn signal issue was fixed after rebuilding the left handlebar switch housing, correcting a grounding issue in the headlight and identifying one burned out bulb.
* Tested for spark and all plugs have spark. Though it seemed faint to me, I don't have anything to compare it to.
* Below is a picture of all the plugs, in order. Seems like 1 & 4 are a little carbon coated, but 2 & 3 look really good. I have no idea what this indicates, so input would be great.

I tried starting again, and it just would not start. I ensured my battery was fully charged, and connected my battery tender to make sure there was enough juice. I would crank it for a few seconds at a time, and then rest a few seconds. After about 30-40 seconds of this, the tone of the starter started to slow. None of the lights dimmed at all, so I don't think the battery was dying. Would this indicate that maybe my starter is dying? Is there a way to test the starter motor to be sure? Is there anything else I can troubleshoot to identify my issue?

[grcamna2]

Do you have a fresh set of spark plugs to install?
I would also think checking the points contacts will help;I hope you have power flowing through both sets of points.

[joegeis]

Do you have a fresh set of spark plugs to install?
I would also think checking the points contacts will help;I hope you have power flowing through both sets of points.

yes, I have only started the bike once since installing the new plugs. I cleaned the points and set the timing since the last start, but will double check nothing has changed.

[grcamna2]

The points might have gotten some grease,etc. on them.
The fouled plugs 'tips'/center electrodes could be cleaned with a SS wire brush lightly brushed with some carb. cleaner sprayed into them. Try to avoid brushing the center porcelain with the SS wire brush,just the center tip.

[newday777]

Do you have a fresh set of spark plugs to install?
I would also think checking the points contacts will help;I hope you have power flowing through both sets of points.

yes, I have only started the bike once since installing the new plugs. I cleaned the points and set the timing since the last start, but will double check nothing has changed.

If you have only run it in the shop, that is why they soot. These bikes don't like to idle for long periods. Once you ride it on the road and do a proper plug chop, then you can 'read the plug colors'.
In the mean time, use a propane torch to burn out the black in the plugs.
A wire brush is not a great idea as any wire bits in the porcelain will cause a direct lead to ground and misfire.

[joegeis]

tried again this morning. The starter was cranking strongly again, but I could only get it to fire up with starting fluid, and only for 1-2 seconds before it died. Where do I go from here??

[grcamna2]

Clean or replace the plugs,then check the spark on all four plugs after you've removed them while sitting them on top of the engine to ground them.

[joegeis]

I just did this last night. Each one had spark, although they all seemed a little faint to me. Not sure how bright they should be, but I had to look closely for the spark. Maybe I'll try to capture on video?

[grcamna2]

I hope your coils are getting enough voltage while cranking.

I hope another forum member will come on here and confirm what the voltage is supposed to be to the coils,while the engine is cranking: HondaMan? Two Tired ?  anyone else ?? 

[joegeis]

I hope your coils are getting enough voltage while cranking.

How do I test that? I have a multimeter, but I don't really know what I'm doing with it yet

[RAFster122s]

Voltmeter measure the voltage in yellow or blue wire to the coils...
Should be fairly close to battery voltage...
If your work area is brightly lit by sunshine then the spark will not be as bright. Should be a blue arc...how fat it is depends on many factors.

[joegeis]

Voltmeter measure the voltage in yellow or blue wire to the coils...
Should be fairly close to battery voltage...
If your work area is brightly lit by sunshine then the spark will not be as bright. Should be a blue arc...how fat it is depends on many factors.

spark was blue and area was well lit. I'll let the voltage today. Also found this video on testing coil resistance, which I will follow and post results here.

[joegeis]

okay, I think we all underestimated my incompetence with a multimeter... I did test voltage at the battery, just to make sure it was working. I get 13.1 volts, after having the battery on the tender for the last few days.

To test voltage to the coils, I turned the key to on, then connected the red probe to the yellow wire coming from the main harness. I tried connecting the black probe to both the black wire and the engine, and although the numbers bounce for a second, the meter lands on 0. Same with the blue wire. I have my multimeter set on "V- 20." Do I need to be hitting the start button to see voltage to the coils?

Then I tried to test resistance on the coils. I changed my multimeter to "ohms 20k" and connected the probes to the blue wire (or yellow)and the black wire with white stripe. Again numbers bounce for a second and then land on zero. I get a positive beep when I test for continuity, which I didn't think should happen.

I can't get any readings or continuity testing from one spark plug cap to another.

Am I goofing this up?

I'm just going to clean up all the rust on my grounds here at least!