Topic: Quitting on the road and finally blew main fuse

[Gaither]

Re: '77 CB550F - sorry this is so long but please, I need your experienced help.

This problem may/may not be related to my recent "No headlight &  no left-front turn signal problem which, thanks to you guys, was corrected by running a new ground wire. [I was "borrowing" Seannh's current post about his headlight/turn sig problem.]

The bike has quit 5 times - just like turning the switch off. Four times, I turned the ign switch off, pulled over and moved the petcock to Reserve. Each time, the bike started right up. Once I got the petcock to Reserve before I got stopped and the engine picked back up and went on. Every time it did this, I switched the petcock back to Running position and it would quit again - sooner or later. So, like a dummy, I replaced the petcock [with an NOS petcock] - which appeared to be the cause of the problem.

When I replaced the petcock, I drained the tank all but about 1/2 gallon through 2 new paint strainers. I sloshed this good, poured it out the filler opening onto a clean white cloth. Absolutely no trash in the paint strainers or on the cloth! Tank filter looks new. Inside of tank bright and shiny. Nothing in a transparent extra fuel filter in the fuel line. Carbs done late last summer.

New petcock didn't prevent engine stopping. Next time out it quit as before. I changed to Reserve and completed a 100 + mile trip with no other problem.

Next time out I got about 60 miles and , running on Reserve, it quit again [6th time]. THIS time the idiot lights didn't come back on with the ign switch.

It had blown the Main Fuse! [Never was a fuel problem!] I put another 15 A fuse in and got about 2 miles and it blew again [7th time]. Getting dark - I put a 30 amp fuse in it and rode it home. Strangly, coming in, I had no tail light - ALL other lights normal. An hour later, I turned the switch on and the tail light came on [didn't start engine].

Next day I rode it 7 miles to a good mechanic. All lights normal. He checked wiring for over 2 hours and found nothing wrong. Put the 15 amp fuse back in and rode home [all lights normal].

The next day I found the no headlight/left fr turn sig outage - which was corrected by a new ground wire today. [This likely caused the tail light problem,too.]

Is there any way the bad ground could cause the blown main fuse or is this another problem?  Could it be in the ign switch?

I appreciate your time and your experienced help.

Thanks

[TwoTired]

See...
http://forums.sohc4.net/index.php?topic=55894.msg602155#msg602155
http://forums.sohc4.net/index.php?topic=2206.msg15960#msg15960
http://forums.sohc4.net/index.php?topic=38214.msg393742#msg393742

[TwoTired]

You could also have bad key switch contacts, or the plug behind it is loose or have damaged contacts.  I speculate that every time you had a stoppage issue you wiggled or moved the switch.  Maybe the other things you did just shifted your attention away from the switch?

[Gaither]

You're right. If an engine stops, I turn off the switch before doing anything else - always heard stitch on, engine not running burns points. However, once, I switched the petcock to reserve before I got stopped and the engine caught right up normally [?]. I kept thinking I had a fuel problem til it blew the main fuse.

I doubt if the bad ground cause a blown fuse. But, I know just enough about wiring to be dangerous.

Thanks for the links, too. I'll check 'em out.

[Gaither]

Thanks, TwoTired.

Had to leave for a while. Been reading your links. I never dreamed fuse "holders" could be so important. The fuse block is in good shape - no sign of excess heat, etc. I can just barely remove a fuse by hand. If it was any tighter, I couldn't by hand.

Although they look good I'm gonna clean the brass Holders like you said - bet a .22 Cal bore brush will do it. Gonna attempt to tighten Holders & use new fused [they are the right length].

Still not sure what shuts the engine down. As you, I suspect the ign switch. [I ordered one yesterday.]

Is it possible something about the bad ground could have shut it down? Til it blew the fuse [7th shut-down] it was only dead for less than a minute and restarted.

Can't get much time on it til Saturday.

'Preciate your help more than I can tell you. 



 

[TwoTired]

Do a really close examination of the plug on the back of the ignition switch.

[crazypj]

Did you check tank cap breather?

PJ

[Gaither]

Do a really close examination of the plug on the back of the ignition switch.

Not beyond making sure it is properly plugged in and looks good. I ordered a new switch 3 days ago [ebay] - found out it shipped today [!!]. It is an Emgo - couldn't locate NOS OEM - I assume Emgo is OK.

Like you, I suspect the ign switch is what is shutting me down. It has never failed to start the bike. When "on" I can move the key about 30 or more degrees from center EITHER direction and the idiot lights stay on. I'm not sure this is normal. Haven't tried this with engine running.

Been out all day and same happens tomorrow. Haven't had a chance to work on bike.

I really appreciate your kind, experienced help.

[Gaither]

Do a really close examination of the plug on the back of the ignition switch.

Yeah, blew it out with 120 psi air press while messing with fuel tank and installing NOS Petcock [ which I'm now sure I didn't need]. It was "breathing" but I did get a little bit of stuff out of the cap. While draining the tank through the old petcock, the cap didn't restrict flow prior to blowing it out. 

'Preciate your idea and interest. Things pointed to fuel flow to start with, I changed my mind when it blew the main fuse.

I'm running and will ride it [with extra fuses along] soon as time permits. 'Just don't know if or when it may blow another fuse. Gonna clean the fuse "holders" first, as Two Tired advised [among other things]!

Ain't old motorcycles fun?? But we gotta love 'em

Thanks much

[Raef]

I have had my 550 for several years and i have had to clean the plug behind the fuse block and even re sodier a few of the wires at fuse holder. Long story short my bike shut off going down the road yesterday, the fuse looked fine but it was bad. I don't know if is vibration or I still have short, but keep extra fuses on the bike

[Gaither]

Thanks Raef

Hadn't thought of wiring on the back of the fuse block. The block looks fine with no signs of over-heating but I suppose this could be a problem.

Yep, I do carry several fused with me - proper 15 amp and 20 amp and a 30 amp "just in case".

I'll chech the back of the fuse block while I'm cleaning the "holders"

'Preciate it.

[Spanner 1]

Please resist putting a 20 or 30 amp fuse in your bike as it's designed for a 15A fuse..... with a fault condition and a 30A fuse , say goodbye to most of your wiring loom due to melting... !!  Should never be necessary as I'm sure the fix is in the advise above, good luck.

[Gaither]

Spanner 1

You're right, of course.

I would only use a 20 or 30 amp fuse in an "emergency" attempt to get the bike home and only then after blowing all the 15 amp fused I had with me.

I did have to put a few miles on it with a 30 to get it home - but no apparent damage. I just couldn't leave it on the side of the highway in the boonies at night  Risky, true. Had no way to haul it in.

Fortunately, the outages have been intermittent. I may not ride it again until I get the new ign switch installed. Plus TwoTired gave me several other things to try.

Good advice.

Thanks

[Raef]

I'll one up the 30.


the first time I lost a fuse was about 11:00 pm 10 miles from home on a county rd, very dark and working by braille I stuck 3 quarters in the main fuse slot and rode it home. Of course this comes with the standard disclaimer, kids we are trained professionals ..... never try this at home

[Gaither]

Raef

Could you call that "a home run"? I love it!

Down here, we "country boys" call what you did "field expediency". Tell us "no" and stand back - there's "always another way"! [But we do get into trouble at times.]

But Spanner 1 is still right.

[TwoTired]

I should tell you that I've read posts that indicate the emgo switches have smaller contacts inside and don't do well in the longevity department.

I've been able to revitalize the Honda switches.  As long as the internal contacts haven't severely burned or the plastic contact holders haven't melted, they can be cleaned and made serviceable again.  It does take some skill, though.

Cheers,

[Gaither]

TwoTired

I didn't find a NOS OEM ign switch on ebay. DId try a couple of dealers - out of stock. Might should have looked further. **Is there a decent source for NOS OEM?

There is no sign of over-heating on the connector.**Must the switch be disassembled to rehab it? [Never even had one in my hand.]

If you refer to cleaning contacts without disassembling, I can do that on the switch and the connector. [I assume the headlight must be removed to get at the switch.]

Please 'splain it in more detail. I ain't too smart but I do read instructions fairly well.

Thanks, TwoTired.

[Gaither]

OK - The Emgo ign sw came today. I got a bit of time. [I hate wiring!]

As TwoTired said, I cleaned the fuse clips - a 22 cal. bore brush is perfect for this - makes 'em clean and bright. Yes, they were oxidized and had a few tiny spots of corrosion.

Removed the orig ign sw. No sign of heat damage - looks OK - just oxidized and crudy connectors. Polished sw connectors with Dremel brush - contacts now clean and bright.

1. Can't figure how best to clean the connector contacts. Plugged 'em about 2/3rds on sw and wiggled 'em for a while. Have some contact cleaner I'll spray into wire connector - doubt it will help much. Will coat sw contacts good with "dielectric] grease at assembly time. Otherwise,

2. Now the question of which ign sw! Do I use the orig sw or the new Emgo? Nothing visibly bad about orig sw. However, I don't know how to disassemble to see inside. And, everyone says the Emgo sw wont last. How many miles are they good for? Might be better to install the Emgo for now and see if my "shut-down" problem persists [?]!

***Please share your thoughts?

Thanks

Gaither

[TwoTired]

You've got it, use it.  I think some others have reported that theirs worked fine for a year or so.

Cheers,

[Gaither]

TwoTired

Ah, you're back! Yeah, I used it - check your PM's.

The Emgo sw is on and the bike is running - gonna test ride next week.

I look forward to your ign sw info & pics.

Thanks much

Gaither

[Gaither]

TwoTired    [Sorry this is long.]  Still a '77 CB550F ign sw.

Finally got time and the guts to take this ign sw apart! Warn't too bad with your instructions. Looking at the contacts, I'm beginning to seriously doubt the sw is what has been shutting me down.

It isn't exactly like the sw in your pics. But, with only 12550 miles, I'll bet it is original.

The first thing you see are 2 bearings [individual balls]. When you wiggle the 2 pieces apart [no release] each ball has a spring. The balls and springs provide for the detents in various sw positions. What holds all this together is a round "spindle" molded [nylon] into the center if the internal piece which has a slightly raised portion at its end. This "snaps" into the bottom of a round hole in the center of the other piece [also nylon] which has the Plug connectors. There is no "release" mechanism. You just have to carefully wiggle it apart. It's 33 years old and brittle!

Am I confusing you? I've got to get a camera!

The 2 movable contacts [that turn with the key] each have 2 [not 3 as in your sw] points for contact with the other various internal sw contacts. They are "L" shaped - the L goes into the upper, removable part of the sw [that turns] and are positioned at about 165 to 170 degrees - one from the other. The piece with the wire connectors has 5 contacts embedded in it positioned to make up the various sw functions. so much for the description.

Fortunately, there is NO heat damage inside the sw. [The only hint of heat is on one of the prongs of the external connector and it is "evidence" of heat with no real damage.]
***Yes, the grease has dried and the internals are very dirty. There is zero wear on any of the contacts. The "plug-in" connectors are tightly connected to the internal sw contacts.

***The only way this sw could have failed would be due to dirty contacts - although that might be possible - when coupled with very dirty "plug-in" external connectors.

My thought is to clean it very well and assume this is a good place for a liberal coating of dielectric grease - IF you agree. I ain't gonna put it back together until I hear from you.

Please share your thoughts candidly. If I've overlooked something, Please say so. I know almost nothing about "electrocusity".

'Preciate your kind assistance VERY much. You contrubute greatly to this Forum [as do some others].

Gaither

[TwoTired]

If the heat damage has not changed the contact geometry or contact pressure, then cleaning and reassembly is in order.
I must admit a word description, while good, is not like actually seeing it.  So, I can't "bless it", as it were.

Did you find any external markings to indicate who made the switch?

Cheers,

[basedrop]

I had something like this.  My problem was the battery was shifting around in the battery box when I was riding, when I accelerated the hot lead would bump against the frame and short the main fuse.  Make sure the battery hot lead can not bump against metal.  Another time the main hot wire leading into the fuse box was getting giggled loose in the back of the fuse box.  Most recently the hot wire from the solenoid to the fuse box connector was corroded and therefore the connection was intermittent.

[Gaither]

TwoTired

Sorry about no pics. No camera!

Visualize a perfect but dirty switch
There is absolutely NO heat damage and NO wear of contacts or components whatsoever. So, I'll put it back together -clean and lubed of course.

****My major puzzle is would a dirty [internally] switch, contacts and fuse clips stack up and shut the engine down? And, would all these factors blow 2 fused?

Thanks

Gaither

[TwoTired]

****My major puzzle is would a dirty [internally] switch, contacts and fuse clips stack up and shut the engine down? And, would all these factors blow 2 fused?

A key switch gone bad usually interrupts mains power, meaning dead bike or intermittent power.  I don't see how it alone would blow a fuse unless something inside it wandered over to bridge against the metal casework. (seems unlikely)

As described in other posts, the fuse clip connections can heat from contact integrity degradation.  It is possible to melt a fuse with no current flowing through it if you heat it enough.  If the contacts are heating the fuse, the fuse rating effectively changes, as they are usually rated for operation at about 25C, and de-rated above that temp.

One clue is exactly where the fuse "blew".  If it parts in the center, most likely it was a true over current condition.  If it parts nearest the end cap, then it is likely getting heat from the fuse clips or a connection to them.

Cheers,

[Gaither]

TwoTired

Could be no wandering in the ign sw. Nothing wrong in the sw but dirty.

Got one of the fuses in my hand. Not blown in the center. There are two small pieces of metal [been melted] floating in the center of the fuse. Took it apart - it was burned in two at one end [been very hot]. Gonna blame it on the grungy clips.

Puzzle - Could any of this shut it down 5 times before it blew the fuses?

You da man!!

Thanks much

Gaither

[Gaither]

Basedrop

You make some good points. The battery has a proper strap on it - can't movel. However, you mentioned one place I haven't checked - but I will. That is the back side of the fuse panel. I'll look at it.

It's great there are so many helpful guys like yourself "out there". Makes it far easier for guys like me.

Thanks

Gaither

[Spanner 1]

Poor fuse clips with a film of corrosion ( they need to be completly shiny) would cause an intermittent shutdown of all power to the bike IMO.... clips overheated enough to melt ( not blow ) the fuse eventually...... I'd replace the fuse block with a new 3 x blade fuse ( automotive type ) block.......

[TwoTired]

Puzzle - Could any of this shut it down 5 times before it blew the fuses?

Maybe.  If you had floating metal after the first internal parting, a gap may have occurred and the floating metal inside intermittently bridged the gap.
Kinda depends on if gravity and vibration could play a role.  Was the gap at the top or bottom of the fuse in the holder?

I don't know if fuse block replacement is necessary.  If the clips are kept clean and fuses aren't heating, they seem to work well enough.  All my bikes still use the stock fuse panel, so I have no complaints.

Cheers,

[Gaither]

Spanner1

Thanks - the clips are now clean and bright. A .22 Cal bore brush is perfect for this.

I hope you're right about the "shut-downs". Otherwise, I'm still hunting!

'Might make the change to modern fuses [?].

Thanks

Gaither

[Gaither]

TwoTired

I don't know which position the blown fuse was in when it blew. I just removed it and dropped into my pocket. It did burn out at one end. There was "floating" metal that wound up about the center of the fuse.

Haven't ridden the bike since making the changes. I'm waiting for a buddy to ride with me so I wont get stranded alone.

I've got to inspect the back side of the fuse block. Somehow, I hadn't thought to do that.[I know just enough to be dangerous!] I'll do that and report back.

Can't thank you [and others] enough.

Thanks, again

Gaither

[Raef]

I have the blown fuse shut down syndrome with my current bike a few Times the fuses are always warm when it happens, not sure if it is the vibration loose clips or what but it has only happened one time this year. I was wondering if cheap fuses play any roll in it

[Gaither]

Raef

I got fuses at AutoZone - have several amp ratings  readily available - not expensive and look like good ones - I assume good quality.

[Raef]

I was not talking about your fuses I was wondering out load about mine, and the fact that they seem to give up about once a year

[Gaither]

I HOPE this is a "final report".   '77 CB550F  Here's what I did:

Installed a new ign switch.
1. All plug-in terminals cleaned with Contact Cleaner and lubed with dielectric grease - no heat damage found.
2. Tarnished [some corrosion, too] Fuse Holders polished and "tightened" [a .22 Cal. rifle BORE BRUSH works perfectly].
3. Inspected back side of Fuse panel - perfect condition - NO heat damage.
4. Added "Popwood" ground wire [headlight nut to coil mounting bolt] -obviously NEEDED. 5. Checked for loose connections - found none.
6. Cleaned Battery connections -although in good condition before cleaning.
7. Inspected all wiring - without removing tape covering - no obvious problems - no heat damage found.
*Fuel tank Cap Vent was previously blown out. [This was NOT a fuel problem.]

Finally got time and a day cool enough to ride [heat index been 108]. Put in about 70 miles. She ran like a top out and back. That doesn't mean she's "fixed" but it is a good indication. On previous ride, she would get about 3 miles on a 15 amp Main Fuse! So, it may well be "fixed". We'll see!

TwoTired, crazypg, raef, Spanner 1, basedrop and ALL who helped me have my SINCERE APPRECIATION. - - Remember, I hate wiring and know nothing about it. So I really needed your help!  You saved me from taking it to a shop and spending far too much money!

I felt all involved were at least due a "report".

Thanks, men,

Gaither

[Raef]

Thanks for the update, a 30+ year old bike will always want attention, as all bikes do, not as bad as a boat, but close.

Mark

I can't find a smoking gun but I still lose a fuse now and then, maybe once a year.

[Gaither]

Raef

Yeah, everything I cleaned was tarnished and/or corroded - needed attention.

Once a year I could enjoy. Every 3 miles was a bit much! If it is "fixed", I'll never know just what did the job - but, I could live with not knowing.

Thank for your input.

Gaither

[Shooter]

Just because the initial stages of this thread mentioned petcock  a few times...

When I first got my 77 /550 I had the petcock confused. 

The device outer ring has RES imprinted on it but I never noticed the tiny arrow on the actual lever.  I used to turn the long arm of the lever in the direction that I thought was away from the RES.  In fact..I was running on reserve.  It would stutter and stop until I turned it the other way .  Just like the OP.

(The arow points in the opposite direction to the long arm of the lever.)

For the record.  The Lever points down towards the ground.  ( But you all knew that huh!)

[Gaither]

Thank goodness for Owner's Manuals.

But the last thing we want to do is to read 'em!