1974 CB250G5 - FOR SALE!!! More pics!

[manbearpig]

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Well, all the bike larking has left me without transport to get to and from work on. I couldn't be arsed with the waiting to see if this and that will work and in the mean time, the viva is getting a daily battering on the chogged up London streets (the front suspension is making a bit of a din, and I need to give it a brake overhaul)


Anyway, I like toys.









tax and test till may next year. now, the not so bad bits that I didn't see/experience until I got it home/took it for a good long run......







^^ Knackerd stanchions hidden under gators. they aren't the worst, but they are corroded enough to cause a problem and make the seals weep so they need doing before long.

Also, it virbrates quite a bit, but not excessivly, but it doesn't sound like it is running as sweet as it should. the front brake binds like a biatch which is one reason, but I think it may need a carb rebuild/service. other minor niggles are the paint has a few saggs on the clear coat here and there, the rear mudguard needs re-chroming, and the front fender is shot. both of those cost a lot of money. rear fender is like poor quality wobbly children's play pony teeth, front is £120 + VAT from david silver, and stanchions are £90 a side inc VAT - so all pricey jobs.

[datman]

nice tho.
I have same fork prob on my XL250

[mercman]

Overall though, looks to be a very well kept example for a 36 year old bike. Better looking than the later CJ250T. Has a classy look about it.
Nice purchase ;D

[manbearpig]

Unlike the ref, I've got a result! Just got these off the bay.



they're for a CJ250, and they look exactly the same. the running gear of both is almost identical I think? (as was pointed out it was the follow-on from the CB). Anyway, even if the fork bottoms don't match, the stanchions are the same part number as the CB, so I can swap them over. AWESOME! Cost me £30 inc delivery - a saving of £200 if I bought new pattern parts.

[TerraRoot]

I have one of these in the garage, got a 350 engine in it still with the 250 badges (would it still classify as a sleeper even if its dead slow?) it's forever eating the rectifier, lack of use doesn't help the electrics. I think standard airbox filters are getting hard to find now.

[manbearpig]

David Silver still has them - only eleven million pounds as well. Bargain. I've just ordered 47 of them for the hell of it.

www.davidsilverspares.co.uk/CB250G5/part_2200/

www.davidsilverspares.co.uk/CB250G5/part_2201/

Not massively bad I suppose - considering they come with the rubber inlet hose attached as well. Still, with VAT and delivery you're almost at £60 - which is fricken robbery for an air filter IMO - or is it? I expect if the hoses came separately, they would be incredibly hard to find and very pricey. I can't find any for the Z anyway

[93fxdl]

bit late for this but the old skool way of fixing rusty/pitted fork legs is to "sweat" the oil out of the surface with a blowlamp then fill the rust/pits with araldite, flat back with wet n dry then put them back on
that type of front brake was never one of the best and is very prone to the pin which mounts it to the leg siezing and the adjustment screw was such a laugh most people didnt bother with them
a friend had a k4 and he covered tens of ks with it, never very rapid but always kept on ticking until the whole top end wore out, couldnt hear the rattles because of the loud pipes but the smoke from the exhausts was epic
afaicr these have a centrifugal oil filter on the end of the crank
terraroot
strange your having rectifier troubles as a popular mod was to fit honda ones to suzukis which did eat them
ttfn glenn

[manbearpig]

Ah, nice one. yeah, that sounds like waht's going on. I've replaced the spring with a spare valve spring out the benly which is doing something - but I'll take the whole lot to bits when I fut the new forks anyway, and i'll see what I can do in the way of modifications.

Now then - two things. Firstly, it vibrates quite a bit - no massive, but certainly not smooth. the engine seems pretty quiet with no nasty noises, but what are the symptoms of a busted main bearing? would I hear a rumble? It goes alright, but not blisteringly quick. I think the speedo might be a bit inacurate, but reading from that, the most I've had out of it is 60, and it gets pretty lively at 55 (shakey). It might just be that the carbs need a go over. I'm thinking about getting a couple recon kits from DS spares, but they're £60 delivered - do you reckon it's a good investment? (there is no smoke at all)

secondly, and it sort of relates to the first - the right pipe is notably louder and more purcussive than the left, and hotter. The left has an original pipe, and the right is a pattern part. Could it just be the difference in the baffles or is it more likely a fuel problem, related to the poor running?

Cheers guys, input greatfully recived

[93fxdl]

a few suggestions re the vibration
first its an old style twin with no balancer shafts or gubbins so it wont be turbine smooth
but some checks you can do
are all the engine mouts tight?
are the wheels true? are they balanced? have the tyres been stood and developed flat spots?
is the chain ok? does it have any tight spots?
the mismatch between genuine and pattern exhausts is probably just the pattern ones being made from thinner steel
shouldnt affect the running to much as most hondas don't seem to be very sensitive to exhausts probably be better to look for any induction air leaks.also check the ignition timing on both cylinders
the 250 hondas were never the quickest bike around but should be able to hold 60/70.
probably be an idea to check the headstock bearings if its getting twitchy
ttfn glenn

[manbearpig]

yeah, there is some play on the headstock. I'm going to see if I can get away with tightening them as it doesn't feel notchy, but if not, new bearings are readily available. I'm going to go and check the points now, also the plugs look a little old, but not bad - Probably worth checking the plugs when hot as well for mixture. Thanks for the input mate. To be honest, I've hardly had a chance to look at the thing yet - I got back from picking it up in Lowestoft (Britans most easterly town don't ya know.....) at about 2am and I've been riding it to work ever since. The only thing I've done so far is check the oil and play with the brake. I took the front mudguard of as well for a bit of a outlaw look - plus it's knackerd and lets the bike down a bit. Is it illegal though?

[manbearpig]

Well, the new forks turned up the other day.





It took me about 70 mins to drain them, refill them with the correct oil/amount, fit them to the bike, tighten up the headstock bearings, greese up the stupid brake mech, rubdown the shonky mudguard and respary in matt black and fit it to the bike. Result!

Now then, Who has/had an old CB? These brakes are used throughout the old CB's and I want to know what I can do to stop the brake from binding. By the time I get to work the disk will burn my gloves if I touch it. It kinda dampens the old performance - and it needs all the help it can get! It's got new pads, reconditioned master cylinder with a rebuild kit, and I've taken the pivot bolt out and given it a seeing to with the copper grease. Is it just a wibblepoo design (I would have thought Honda would have changed it if it was problematic), or does it just need using and pistons back and forth etc?

[93fxdl]

the options for a sticking brake are
1 the caliper is stiff on the mounting pin making one pad drag
2 the piston in the caliper is stiff making both pads drag
3 the new pads are a bit too thick causing drag
4 the floating pad is sticking in the caliper causing drag
5 the master cylinder isnt returning properly, pressurising the system
6 flexi pipe goosed (dealings with a winebago where the flexi would let the brake on then hold it)
7 lever sticking so dragging the brake slightly

the way i would go through this is first lever back the moving pad to ensure the piston is moving freely and the pad is not jamming in the caliper and fluid is able to return through the master cylinder then ensure the caliper is able to swing on the mounting pin, if there isnt any clearance for the pads, as they heat up they will grip the disk and then get hotter and so on
really its just work your way through the system
ttfn glenn

[manbearpig]

Nice one, cheers Glen. Well, I took it to bits today before riding to work on it. I removed the pin, the pin holder(Holds the top of the pin and bolts on to the forks) and the caliper. filed down the face of the holder to reduce friction when hot and sanded back to a polish. Filed down the pin a little bit, and the base of the pin where the caliper rests on it, and greased well with copper grease. Worked the piston in the caliper back and forth a bunch of times, using a big tyre lever and the brake. put it all back togethre again.

better but still rubs. The caliper moves alright on the pin, the pistons goes in and out ok. I took off the reseviour cap and pushed the piston back and it spurted a load of fluid up all over the handlebars, so I would say it's returning ok, although, it is much harder to push back in again than it is to take out, but then again, it would wouldn't it.

Hose seems fine, pads move around ok inside the caliper.

Warped disk???

[93fxdl]

if disc was warped you would get pulsing through the lever
sounds to me that the piston is dragging,i usually only need a 6 inch screwdriver to push pistons back
you will need to pump the piston right out then clean both the piston and the bore in the caliper
before you start make sure the bleed nipple isnt siezed and when bleeding its a lot easier if you hold the caliper above the handlebars
ttfn glenn

[manbearpig]

Nice one dude, cheers, i'll try and have crack at it tomorrow.

[grizz]

When I started to read of the trouble you were having at the top of the thread, I had hoped you were going to sell it to me.

Lovely looking old bike Dave.

[cresad]

Very nice ;D

I had a bronze/gold 360 version back in the 80's , don't remember having any problems with anything in particular at the time. I know I changed the wheels for some six spoke mag's and stuck a pair of triumph thunderbird rear silencers on ( altho silencers is probably the wrong word ). Wouldn't mind another

Adam

[manbearpig]

Nice, thanks guys. Rian - it's going to be up for sale at some point. I only got it to blat around on whilst I'm fixing the others up. i would love to keep it, but space and money (and wife type) cannot allow so many bikes!

Anyway, result! Only a couple pics as I forgot to take them, but took the caliper to bits the other day and cleaned off the piston. It had been dropped at some point and had a compression bulge on one side, thankfully right at the back corner - so nowhere near a seal at full extent. There were a few little scuffs here and there as well which a filed down with a fine needle file. Honed the bore out of the caliper, removed the seal and cleaned it up a bit, and filed down the outside edge of the pad so it moves a little easier in the caliper.



Back together again and bled off....



been riding it to work for the past couple days and it's free wheeling with the best of 'em! much better performance, and the disk doesn't burn my glove amymore! Glen - thanks for the heads up. I've always been sceptical about taking calipers to bits without a new seals kit to hand, but it went back together without a hitch (or a leak)

[manbearpig]

Yep, it's on ebay if anyone's interested. I'm selling it and the bobber project to 'consolidate' in to one bike I can hack about on. I still ride it around everywhere and it does fine. no smoke out the pipes at all and really reliable, but there is a little bit coming out the breather pipe when it;s hot - but that's it.

Have a look if your inrested......

cgi.ebay.co.uk/Honda-CB-250-G5-1974-CLASSIC-/250712929121?pt=UK_Motorcycles&hash=item3a5fa7b361#ht_500wt_1156

[manbearpig]

A few last pics - only a few hours to go some dude wanted to see mire pics of the wheels and down pipes to see how good the chrome was, and the problem bits, so here's a few pics incase anybody's intrested...

the dull rear mudguard



Paint ripples..



spares paint - 1 and a bit cans of paint, and a bit of laquer - enough of both to respray the tank.



header pipes..



rims...