Topic: new project 77 CB550

[DaveBarbier]

Correct, no polarity on the starter solenoid.

That sounds like the battery is low on charge. I'd check voltage with a meter then put it on a charger.

Regarding the high idle, that's usually because of air leaks (I know you've checked ) but could also be from a gummed up advancer mechanism. Do you have a timing strobe? You should verify that the advance comes in at around 3k rpm and that it hits between the double marks in the window.

So just to confirm, you did the full 3k mile service? Valve adjustment, cam chain, point gap, static timing, etc?

I read that you changed the needle height. Did you bench sync after that? It must be done when changing needle height. After bench syncing, you must vacuum sync. An out of sync bike can also have high idle issues. But in the service, syncing is always the last thing to be done as it is dependent on everything else.

I would pull plugs and verify gap, verify tappet clearance, cam chain, point gap and static timing again, then dynamic timing with strobe, and then sync the carbs.

[mitch5069]

I did just put a new battery in the bike and it turns the engine over without a struggle when I jump the solenoid terminals. I will check the voltage but I'm not putting my cards on it.

I only have a timing light not a strobe. Where is the advancer mechanism located? Is it by the points?

I am 90% sure I did all of the 3k service (it was over a month ago at this point) but I am sure I did not do anything with the cam chain. I did check the valve clearances, cleaned the carbs, checked the points gap, vacuum sync'd the carbs,  I will take a look at the manual and see what I need to do with that.

As far as changing the needle height: I changed the needle height down one clip setting to make the needle sit higher thinking my high idle was because it was running lean. After that didn't work I put it back on the original setting then vacuum sync'd the carbs. and that is where I am today on it.

I have off work today so I might go try to fire it up again and see what I can learn.

[DaveBarbier]

The advanced mech is behind the points plate. It's two pivoting weights with springs. As the bike's RPM increases, centrifugal force throws the weights out and that advances the timing by rotating the cam that the points glide on.

Some times that can be really gummed up and either won't let the bike get to full advance, or won't let it return back down.

It's not good to be only 90% sure you completed the 3k mile service. You should be 100%.

[mitch5069]

Ok that makes sense for the advancer mech.

suppose the advancer mech is gummed up in one of the scenarios you described, how would I clean this? Do I take the points off and clean with some type of solvent? I assume you can visually see if the advancer won't return back?

I do not have access to a strobe light so I am trying to figure out if I can check to see if this is truely a problem.

[DaveBarbier]

You'll see that it'll be gummed up, but taking it off and cleaning it can't hurt if you're in there. Just be aware how it goes together, the cam can be installed 180° out which is incorrect. There are faint marks for orientation. I think a hash mark on the cam and you line that up with the logo.

Also, you can get strobe timing lights for under $22 on eBay

Still not sure if this will solve your problem, but it's worth checking out.

[mitch5069]

Alright so ended up buying new boots to go from the carbs to the intake manifolds to try to eliminate that as a possible leak even though it passed the leak test with propane. When replacing these I found that the intake manifold on one side was not fully secured. I removed those and replace the o-rings for the manifolds then the connecting boots and got it to idle at around 1200 to 1400 rpms. I took it for a couple mile ride and I decided to open up  the throttle past 4k and the bike died. The main fuse went. So I ran to autozone and picked up some more fuses and kept burning them up on the way home. When I got home I had it running and I could watch the fuse burn up as I rev'd the engine high.

Anyone have an idea what would cause that? Would that be an issue with the regulator? I know the PO hand hooked the terminals up backwards and tried to jump it once could this have fried my regulator and the starter solenoid?

[DaveBarbier]

Could be a regulator issue. Does it blow the fuse when your just revving it up and not moving? Hook up your volt meter to the battery and record the voltage readings as you increase RPMs. Note voltage of battery at idle, too.

Does your headlight glow brighter as you climb up in RPMs?

Is your RPM issue fixed?

[mitch5069]

to DaveBarbier:
yes it idles fine but when I rev it at a stand still the fuse blows, not immediately but a few cracks of the throttle.

yes the headlight does seem to get a bit brighter when I rev the engine but I feel like I've seen this on several bikes i've owned and the idling issue seems to be fixed.

to Calj7373
How to I test the regulator? I looked online at http://manuals.sohc4.net/cb550/ under Part 4: Electrical and it didnt really give me any information (well I didn't exactly understand what it was asking me to do). So to answer another question the wire harness is stock but I did take a closer look at it and found that there was some copper exposed on the green wire coming back the harness. I put pictures below.

Some other information I noted last night:
bat voltage with key off = 11.93V
bat voltage at idle = about the same
reving the engine (maybe up to 5Kish) = never above 12V
Per he service manual at the link I posted above I reviewed the regulator and found that the core gap was about .035" which is within spec and the point gap was much less than .008" (.008 is what it should be set at per the manual) and looked to be fouled. I buffed the points with 600 grit sand paper and set the gap to .008". I reinstalled the regulator on the bike and started it up again. With the 15A main fuse in I could rev the engine and watch it smoke and bow in the tube.

Note: all battery measurements were taken before I adjusted the regulator. Not sure if that matters or not.

Is this pointing me in the direction of the rectifier? Shouldn't the batter voltage go up around 14V when reving into the charging zone?
I guess I should take the wiring harness out and look for it shorted to another wire???

[mitch5069]

So last night I took a look at the wire harness and found that the green exposed wire was not shorted to anything else. I retaped over the exposed wires and then cleaned the terminals on the fuse block and I left the battery on charge overnight. This morning the charger was off so the battery was fully charged. I waited a few hours and started it up again. With the multimeter hooked up the the battery terminals a rev'd the engine to around 5K and saw the multimeter jump to into 16 volts and the the fuse went out. Maybe I do have a faulty regulator after all. I will follow the troubleshooting guide and keep everyone posted. Might end up going down the path of a regulator/rectifer all in one. Any thoughts on one of these?

[mitch5069]

I haven't had a chance to check the black wire from the regulator but I did look at a schematic and had a question. I used the schematic in the link below and I noticed that the black wire goes to something called the "starter magnetic switch", what is this? is that just the push button on the right control? When I am comparing the voltage on the battery to the voltage going to the regulator what wires should I be checking? The black to the white wire?

http://oldmanhonda.com/MC/WiringDiagrams/CB550.jpg

[mitch5069]

So I dug into this a little more and checked some voltages and they are as follows:

battery voltage (with the key on) = 11.88
Voltage to red connection on solenoid = 11.84
voltage to yellow with red stripe wire going to solenoid (with starter switch pressed) - 11.38
Voltage to black wire on fuse block (7A fuse) = 10.54
Voltage to black wire on regulator 11.02
Voltage to black wire on turn signal relay = 11.05

one thing I did find very odd is there looks to be a large green resistor on the regulator that was very hot when I was checking voltages. I would like to note that I did not start the bike to get these voltages only had the key on.

Do these values seem normal to you guys? I think the trouble shooting guide says check voltage across battery and compare it to the voltage to the black wire on the RR which I assume is the regulator since there is no black wires on the rectifier. Is it normal for the resistor on the regulator to get hot? when I say hot I mean you can only keep your finger on it for a second before it is too hot to handle.