Author Topic: Cb550f blowing main fuse  (Read 15386 times)

Offline deltarider

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Re: Cb550f blowing main fuse
« Reply #45 on: August 13, 2026, 08:24:37 AM »
My CB500K2-ED came with a Hella H4 reflector, model: 1A6 002 395-071. What I particularly like, is that the lens is flat, which gives your bike a serious and classic look. It has an extra Ba9s socket for a position light. It is not an expensive one and back then was also fitted on the VW Golf in Europe. Still available and cheap.
Best DRL in my opinion is a not too bright yellowish headlight like in the pic. European research has established yellow is best noticed. The CB550K3 in France had the best. It came with a yellow Phlips 60/55 Watts H4, Honda partnumber: 34901-371-621 which according to CMSNL is on 185 other Honda models. Price a bit hefty: € 37,46 but might be cheaper in France.

Offline florence

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Re: Cb550f blowing main fuse
« Reply #46 on: August 13, 2026, 10:22:20 AM »
envious about the Cibie Z headlamp.  In the 1980s I had one on my CB350.  It was excellent beyond compare.  Sadly, the reflector corroded eventually and I have tried in vain to find another.  Examples for sale seem either corroded, or very very expensive.

Offline deltarider

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Re: Cb550f blowing main fuse
« Reply #47 on: August 13, 2026, 12:36:28 PM »
My Peugeot 504 GL had those wonderful trapeziumshaped Cibié headlamps. Never had better. Guess what US legislators forced Peugeot to do. Peugeot had to replace them by inferior sealed beams! But hey, you now had 4 lights and 4 is more than 2 right?! ;D

Offline Oddjob

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Re: Cb550f blowing main fuse
« Reply #48 on: August 13, 2026, 02:19:15 PM »
envious about the Cibie Z headlamp.  In the 1980s I had one on my CB350.  It was excellent beyond compare.  Sadly, the reflector corroded eventually and I have tried in vain to find another.  Examples for sale seem either corroded, or very very expensive.

I paid £80 for it, in extremely good condition as well. I bought a pair just before the coma last year, however when they were delivered they were the smaller type, might even be 5.75” to suit the 400, bit not the concave type, convex like the z beam 7”. No idea where the wife’s put them, I was already feeling ill so I wasn’t particularly interested in looking at them too closely. If they are 5.75” I may sell them to 400 owners.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Otis

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Re: Cb550f blowing main fuse
« Reply #49 on: August 16, 2026, 06:30:15 PM »
Strangely enough, after a 75 mile faultless ride this morning with three good stops I pulled into my drive and suddenly everything went dead.

My initial thought was that perhaps i should have initiated the reserve setting for the fuel. Not the case as there was plenty of fuel. I checked the battery and was getting a 13.3V reading. The next step was the main 30amp fuse and found it had blown. Cleaned the contacts and inserted a new fuse and all is well but just wondering if there could be any cause for such an event?

Cheers
Graham

1972 Honda CB350F
1997 Ducati ST2

Offline Oddjob

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Re: Cb550f blowing main fuse
« Reply #50 on: August 16, 2026, 06:38:56 PM »
30amp is way too high. 15 is more like it.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Otis

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Re: Cb550f blowing main fuse
« Reply #51 on: August 16, 2026, 07:40:26 PM »
30amp is way too high. 15 is more like it.

Ok I understand that but what would make a 30amp fuse suddenly blow; it would have been the same with a 15 amp
Graham

1972 Honda CB350F
1997 Ducati ST2

Offline Oddjob

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Re: Cb550f blowing main fuse
« Reply #52 on: August 16, 2026, 08:07:48 PM »
What blows a 30 would certainly blow a 15, that’s not the point though. There is a risk of melting wires or even starting a fire by fitting a 30. It takes a lot to blow one so the heat build up can mean a disaster. Not as bad a fitting a nail but best to stay below 15 and stay safe. Any bulbs blown? Or what was working when it blew.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Towsejames

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Re: Cb550f blowing main fuse
« Reply #53 on: August 16, 2026, 10:33:43 PM »
Today I took mine on a good ride, 50-60miles or so. This was with the new fusebox and cleaned up connections. I’m happy to say all was well. Me and my brother attended Hornsea bike show, me on the 550 and him on his 1976
Kawasaki z650. I did have a hiccup when the bike started misfiring and cut out, luckily I noticed the choke had knocked on, a quick switch back into the off position and all was well. A good blast using all the electrics including the headlight and everything seems well.

Only thing now is I think I need some new clutch plates as it felt funny by the end of the day requiring some adjustment and occasionally slipping slightly.

All in all though, after over 20 years off the road it’s back cruising again.


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Offline TrickyMicky

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Re: Cb550f blowing main fuse
« Reply #54 on: August 16, 2026, 11:18:25 PM »
I hope you did not take up the slack in the clutch cable while the engine was still hot, I think most of the 4's develop some slack when warmed up.  When it has cooled off the slack disappears, meaning if you had tightened it when hot you could have clutch slip.

Offline Oddjob

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Re: Cb550f blowing main fuse
« Reply #55 on: August 17, 2026, 12:23:55 AM »
I have around 3-4 full clutches for the 550. You want a set of plates, steel or friction?

Just pay the postage.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Otis

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Re: Cb550f blowing main fuse
« Reply #56 on: August 17, 2026, 01:27:10 PM »
30amp is way too high. 15 is more like it.

Thank you for confirming as I only replaced the first one with what was already in there. Even the Haynes manual doesn't appear to give guidance on fuse ratings but that doesn't surprise me. In the last 50 years I have never found a Haynes Manual to be useful: it only gets you into deeper trouble because it gives the impression it is thorough but they are pretty much all useless.
Graham

1972 Honda CB350F
1997 Ducati ST2

Offline Oddjob

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Re: Cb550f blowing main fuse
« Reply #57 on: August 17, 2026, 02:08:09 PM »
IIRC it's onex15 amp in the main fuse and 2x7 amps in the lights and tail.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline deltarider

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Re: Cb550f blowing main fuse
« Reply #58 on: August 17, 2026, 03:39:12 PM »
The models with 3 fuses had: 15A (main) 7A (head) and 5A (tail).
« Last Edit: August 17, 2026, 03:40:50 PM by deltarider »

Offline taysidedragon

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Re: Cb550f blowing main fuse
« Reply #59 on: August 17, 2026, 04:40:23 PM »
30amp is way too high. 15 is more like it.

Thank you for confirming as I only replaced the first one with what was already in there. Even the Haynes manual doesn't appear to give guidance on fuse ratings but that doesn't surprise me. In the last 50 years I have never found a Haynes Manual to be useful: it only gets you into deeper trouble because it gives the impression it is thorough but they are pretty much all useless.

Maybe that was a bodge by the previous owner because it was blowing 15A fuses?
Gareth

1977 CB400F
1965 T100SS