Author Topic: 1976 Honda Cb550F supersport troubleshoot  (Read 2521 times)

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Offline Lakelife31

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1976 Honda Cb550F supersport troubleshoot
« on: August 23, 2017, 06:13:49 PM »
UPDATE: RUNNING OK - Rough idle, but seems to be good. How hard can I pin this thing? I read a post earlier that indicated I should just give it super hard, because these engines like it? I'm so afraid to go over 5000 rpm because its just screaming- see below, thanks all for help.

Hello all
So I an trying to start a bike my brother had running great last year. sat for a mild winter in BC, and now, am trying to get it going again. Keep in mind the gas sat for awhile. i tried jumping it and could not get the bike to fire at all. Just straight ignition, then I noticed it kept blowing my main fuse, so I tried again and now it looks melted. I know its probably not the snake. Is there a simple troubleshoot pattern I can follow to isolate some issues. bear with me. New to this. Thanks in advance.
« Last Edit: August 29, 2017, 11:37:54 PM by Lakelife31 »
1976 Honda CB550F Supersport Cafe

Offline BomberMann650

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #1 on: August 23, 2017, 07:16:15 PM »
How many amps were you sending from the jumper?

Offline Lakelife31

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1976 Honda CB550F Supersport Cafe

Offline Lakelife31

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #3 on: August 23, 2017, 09:27:24 PM »
How many amps were you sending from the jumper?

Hey! Sorry, It was just my car battery and jumper cables. Cannot verify that. Definitely a newbie.
1976 Honda CB550F Supersport Cafe

Offline TwoTired

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #4 on: August 24, 2017, 12:16:45 AM »
Your fuse box is beyond saving.
Replace it.
Thats step one toward saving the bike.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline CycleRanger

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #5 on: August 25, 2017, 08:19:03 AM »
How many amps were you sending from the jumper?

Hey! Sorry, It was just my car battery and jumper cables. Cannot verify that. Definitely a newbie.

Did you hook the jumper cables up backwards? 
In addition to the fuse block you could have damaged the rectifier as well.

Repair the fuse block and properly recharge the the battery or replace it with a new one before you try to start it again. :)

And go here and download a copy of the shop manual.
http://www.honda4fun.com/materiale-documentazione-tecnica/shop-manual
« Last Edit: August 25, 2017, 08:20:39 AM by CycleRanger »
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
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Offline Bankerdanny

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #6 on: August 25, 2017, 07:22:25 PM »
Jump starting with a car battery should work fine, jump starting from a running car however is very bad and could cause the damage you saw.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline TwoTired

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #7 on: August 25, 2017, 08:00:24 PM »
Jump starting with a car battery should work fine, jump starting from a running car however is very bad and could cause the damage you saw.
Please explain why the latter?

I don't agree.

Far more power in a battery than an alternator.  Voltage is voltage and current flows per demand.

Fried rectifier is usually from applying reverse polarity.  Only takes a second.  Poof.
Can also get damaged from no battery or an open circuit battery while bike is running.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Bankerdanny

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #8 on: August 26, 2017, 08:10:35 AM »
You're the electrical engineer, so your knowledge is greater than mine, but my understanding is that a 12v battery is a 12v battery. The car battery just has a higher reserve.

The car's charging system however has a much higher amperage capability due to the higher draw of the various systems in a modern car and so when it is running it is likely pushing more amps through the system to keep it's own battery topped off than the old Honda system is designed to handle.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline Airborne 82nd

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #9 on: August 26, 2017, 11:25:19 AM »
Don't poke the bear ;D

Offline TwoTired

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #10 on: August 26, 2017, 04:33:52 PM »
A starting battery has a rating, and for cars that's in the 500-600 amp range.  You can purchase more or less.  However, you can draw much more for shorter periods of time.  This only matters if you have a load that demands it, like if you hook up a rectifier backwards.  Presenting a direct short to a battery will draw max current for as long as the load device survives. (Not long)
Vehicle alternators vary in output capability.  30- 60 amps typical, with some heavy duty examples as high as 100 amps.  There is 5 to 7 times or more power available from a car battery.

That leaves over voltage as a consideration.
12 v batteries attain 12.6 v at rest.  And their charging systems are supposed to limit battery charge levels to 14.5v.  And that applies to both bikes AND autos.  So, unless your running power donor vehicle has a faulty charging system, how will it provide more voltage than what a bike routinely experiences? Further, higher voltages that might harm the bike at the end of a long cable, would certainly threaten, if not damage the power donor vehicle.

I speculate the runnig vehicle myth was started by someone who simply could not bear the admission that they f'd up when connecting leads, even if briefly.

Personally, I've jump started both bikes and autos and it never made a difference if the donor was running or not.  And, if the dead vehicle took too long to start, I made sure the power donor vehicle WAS running so as to not deplete it's battery.

If there is a technical explanation to change my understanding, I'd be willing to listen.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline jonda500

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #11 on: August 26, 2017, 07:58:42 PM »
+1 you cannot hurt your bike by correctly connecting with jumper leads to any 12 volt car, bus, truck, tractor, boat, forklift, etc - provided the donor vehicle isn't overcharging, but even if it is, just turn it off before connecting the leads and it'll be fine! (probably wouldn't need the vehicle running to turn over a bike engine).
John
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Offline FuZZie

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #12 on: August 26, 2017, 08:48:17 PM »
All this fun stuff aside, lakelife you need a fuse box and from the look of the wires under it probably some other work. look up member hondaman and PM him(you'll need 2 more posts first). He makes fuse box upgrades you get to use modern blade fuses yet it looks like it's oem. 

Offline Airborne 82nd

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #13 on: August 27, 2017, 12:58:34 AM »
All this fun stuff aside, lakelife you need a fuse box and from the look of the wires under it probably some other work. look up member hondaman and PM him(you'll need 2 more posts first). He makes fuse box upgrades you get to use modern blade fuses yet it looks like it's oem.

http://sohc4shop.com/catalog/product_info.php?manufacturers_id=12&products_id=48&osCsid=fa3c8d5e9048e194e45a44c27429d49c

Offline Redline it

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #14 on: August 28, 2017, 08:05:30 PM »
lakelife, I'm not a certified SOHC tech consultant,  the fuse box that's melted is still ok to use even if the fuse holder falls through the melted hole.   simply solder the main wires to the spare holder which hasn't burnt,  the uppers look good, the main got a little hot. unsolder the wires going to the melted pins, pull or push the spare fuse holder out of the plastic and then solder them and you have to spread the base of the holder and snap it back in, keeping it spread with something then pinch the tube that holds the fuse so it'll fit.  figure out why it melted before before you melt your newly soldered piece of work, i had a couple of years of dying battery and had to jump it from cars, maybe 20 times, because it was so dead that it wouldn't kick or push start, without excessive connection time, a soon as i made the connections I'd kick it and be running. i'm still using same fuse box, it got a little melted itself. that why i soldered the space slot, haven't had trouble since. I'd keep it for a spare if you buy a new one. if you're going to throw it away and you live in the US I'll pay for postage and beer for it.

Offline TwoTired

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #15 on: August 28, 2017, 08:18:13 PM »
The design of the stock fuse box allows the fuse clips  to float in the holder.  This allows the clips to self align with the fuse ends for maximum contact area.  The more contact area the less resistance, the less heating when current flows through it.  Using an unmelted portion of the fuse block is a decent strategy.  But, when soldering, do so with the clip out of contact with fuse block, as soldering temps will melt the fuse block.  Melted fuse blocks will usually prevent the clips from attaining proper contact area with the fuse ends, leading the fuse heating and more melting of the fuse and clips.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Lakelife31

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UPDATE Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #16 on: August 29, 2017, 06:21:09 PM »
UPDATE:
Hi all,
Thanks so much for all the help. Here is the interesting part, I had jumped this bike at least 20 times from my running car and never had an issue. This was something that happened quickly just the last time, and I must admit, it might have something to do with the fact that I popped the 7amp fuses into the main and used them all up trying to get it going in desperation. Beforehand, the fuse box hadn't yet started to show signs of heat. Despite my lunacy.

With that, I put the fude box back, I popped the battery onto a12v trickle(all I had) but only on 2 amps. I took the sparkplugs out, they were somewhat fouled, but brushed them off, tested for a spark, and it seemed good. once putting everything back into place, I tried to turn over, and to my utter amazement, it fired, then died. Then again, the same, then all of a sudden she came to life. The fuse box actually still works fine. That being said, your not going to believe it, but I am walking my dog late last night and my flashlight catches the headlight of a completely forest-debris-laden 1974/1975 cb750 supersport. One of the few models that has the literal exact fuse assembly. So I knocked on the door, 20 minutes later I was in my way with the part for free. VERY nice person. Anyhow. The only issues now are trying to dial in the throttle stop screw between the hot and cold idle differential and knowing when to leave it or twist it. It seems to have a massive bearing on the idle success. And the throttle sticks a touch, and it is not the wires. Carbs? Thanks again all, I will try and respond individually later. Cheers.
1976 Honda CB550F Supersport Cafe

Offline CycleRanger

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #17 on: August 29, 2017, 06:51:12 PM »
What, you couldn't get the whole bike?!  :)
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
https://www.honda4fun.com/materiale/documentazione-tecnica
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Offline BomberMann650

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #18 on: August 29, 2017, 08:43:28 PM »
What, you couldn't get the whole bike?!  :)

Right?!?  You have to go back!!!

Offline Lakelife31

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #19 on: August 29, 2017, 11:04:21 PM »
What, you couldn't get the whole bike?!  :)

Right?!?  You have to go back!!!

Its pretty rough, but it seems to have all the original components. but wow is it rusted and seized. That being said, are there any useful parts off it that I might adapt to mine?
1976 Honda CB550F Supersport Cafe

Offline TwoTired

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #20 on: August 29, 2017, 11:09:02 PM »
Be sure to polish the fuse clips on your replacement fuse box, or you'll soon be shopping for another.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Lakelife31

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Re: 1976 Honda Cb550F supersport troubleshhot
« Reply #21 on: August 29, 2017, 11:31:27 PM »
Be sure to polish the fuse clips on your replacement fuse box, or you'll soon be shopping for another.

Cheers,

Cheers, I certainly will. Do you recommend a specific cleaner? I have some degreaser? Vinegar? The assembly is in pretty good shape. Is there any reason why in his main fuse which calls for a 15amp fuse, he had a weird fuse with paper inside saying "17 amp continuous LUCAS 35 amp" Original melted fuse box and new fuse box pics below.
« Last Edit: August 29, 2017, 11:57:55 PM by Lakelife31 »
1976 Honda CB550F Supersport Cafe

Offline Bankerdanny

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Re: 1976 Honda Cb550F supersport troubleshoot
« Reply #22 on: August 30, 2017, 04:59:08 AM »
I just use 0000 steel wool. It will shine the contacts up nicely. Works great on chrome too.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline mj1176

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Re: 1976 Honda Cb550F supersport troubleshoot
« Reply #23 on: August 30, 2017, 07:58:25 PM »
Best option in my opinion is to just replace the old glass fuse box with new blade fuse holders. makes it way easier, and it's a 20 minute job.

Also, regarding your question about pinning it, if it's in good running condition you can push it pretty hard safely. I regularly shift at 6-7k and you can cruise at 6k in 5th all day long.

Offline Bankerdanny

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Re: 1976 Honda Cb550F supersport troubleshoot
« Reply #24 on: August 30, 2017, 09:07:50 PM »
I spent several hours over the past couple weeks cruising at 80mph on my 550F through Nebraska, Arizona, and New Mexico on highways with 75mph limits. The bike can handle it fine. It's the functional equivalent of a modern car with a 6500rpm rev limit cruising at 3,000rpms.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200