Hi

[davey]

Hi there,

just popped on to say hello. Had my honda CB500/4 for just over a year now and done about 4000 fun filled miles on her. This is my first bike having previously been an owner and rider of classic scooters (and still am) and I am absolutely loving it. Not had any problems until started spluttering and misfiring in the wet. Someone who knows more about these bikes than me said its actually a 550 frame with 500 engine (did they make them like this??) I bought it from a dealer and it had about 3000 on the clock and was imported from Italy 10 years ago.

Anyway may well be posting for the occassional piece of advice.

all the best 

[JonnyB]

Welcome Davey,

Someone here will be able to help.. In my experience damp problems tend to be plug caps shoring in the damp.

BTW
I used to have a scooter too, I bought a PX125 Vespa when that model first came out. loved it 175 big bore kit, 28mm del delorto carb, cut down leg shields. - Brilliant

[Bryanj]

Post the frame and engine numbers plus a pic of the clutch cover.
In Europe they had a 500K3 as well as a 550 so it could well be one of those. With the details I can tell you exactly what you have

[SteveD CB500K0]

Your avatar looks like a CB500K3 - which as Bryan says, they had in some European countries (but not here)

WRT to misfiring in the wet - a common problem I'm afraid.

You'll need to go over the plug cap / HT lead joint very carefully. If in doubt, replace plug cap and snip 1/4" off the end of the lead before screwing in the new one.

The other place that suffers from water ingress is the joint between the HT lead and the ignition coil. This faces forwards (under the tank) and collects all the wet thrown up from the road. In the past I have wrapped clingfilm around the offending area for a short-term fix. In the long run, remove the coils and treat the area with RTV (Room Temp Vulcanising) rubber sealers after first roughening up the surface of the coil.

Others have replaced the coils with either modern stuff (eg CBR600) - but may need to fabricate bracket, or those from the DOHC CB750/900 which have removeable HT leads.

[davey]

Thanks for the excellent advice gents, will give your suggestions a go and let you know how I get on. IN the meantime its the lambretta or the pushbike if it rains!

Will post a pic of the bike but it does not seem to like pics of more than 400K.

[SteveD CB500K0]

There's a limit to the size of uploaded pictures (to preserve our server space). In reality, no more than 100-150k should be required for a picture that is to appear on a 72dpi screen.

You could host them and link to them. Instructions here:
http://forums.sohc4.net/index.php?topic=14605.msg93296#msg93296

Link is to a FAQ on www.sohc4.net - a separate entity but same software (and I wrote the FAQ)

Steve

[davey]

I will see if I can get some pics posted up.

Just cut back the HT leads a bit and refitted caps (with a few drops of ignition sealant).

Wrapped some plastic around the coil / ht lead junction in an attempt to bodge it. Hoping for some rain so I can see if me bodge works, and will see if I can get some RTV sealers. The bike has been fine through wind and rain and have ridden it in torrential conditions and it only started playing up last week so hoping I can solve this.

Once again thanks for the advice guys