Bad Buttercup!

[wilf]

Aah, Silverstone Classic, an annual pilgrimage for me, so much to see and watch.

Buttercup made her first visit there last year, and after a year of upgrades repairs and mods, I was looking forwards to a smooth run this time.

Not to be. Engine decided that 8 cylinders were unnecessary and 4 would suffice. Managed to limp there and staggered (sorry) onto the club pitch.

Spent ALL DAY wrestling with fuel pumps, carbs, coils, to little avail. Many many thanks to Roger Phillips who gave freely of his time and ultimately his spare fuel pump.

But Buttercup was not to be swayed, and we limped home again on a similarly reduced number of cylinders, teaches you to conserve momentum!

Think it will come down to a carb issue, maybe a stuck needle valve, but my back is so wrecked form all the leaning over yesterday that i am effectively laid up today myself.

Anyone got a fuel pump they might sell?

Classic cars, you have to love them.

[MandM]

Had the same thing on the Ipswich to Felixstowe run, had the carbs off on the prom, with the crowds walking past saying they weren't any good in the 70's,anyway turned out to be *hit in the petrol only running on one carb, 4 cyclinders, cleaned out carbs, new filter fitted, off we went back on eight. cleaned tank out when home and added a filter before the pump, hope you so feel better

Nice colour

[Staggard]

Aah, Silverstone Classic, an annual pilgrimage for me, so much to see and watch.

Buttercup made her first visit there last year, and after a year of upgrades repairs and mods, I was looking forwards to a smooth run this time.

Not to be. Engine decided that 8 cylinders were unnecessary and 4 would suffice. Managed to limp there and staggered (sorry) onto the club pitch.

Spent ALL DAY wrestling with fuel pumps, carbs, coils, to little avail. Many many thanks to Roger Phillips who gave freely of his time and ultimately his spare fuel pump.

But Buttercup was not to be swayed, and we limped home again on a similarly reduced number of cylinders, teaches you to conserve momentum!

Think it will come down to a carb issue, maybe a stuck needle valve, but my back is so wrecked form all the leaning over yesterday that i am effectively laid up today myself.

Anyone got a fuel pump they might sell?

Classic cars, you have to love them.

Fame at last It's not s split carb diaphram is it ??

[wilf]

Had a gentle fiddle today. Took the carbies off, and while I could see nothing amiss, I reckon one needle valve might be a little sticky, have ordered some viton tipped ones.

Also found a strange "hang up" where the dashpot dampers are intermittently seizing in the bores of the pistons. No rhyme or reason to this one, will take the pistons out and clean the bores with some extra fine wet and dry to clean out any surface irregularities. Strange one this.

Managed to find a fuel pump, SU metal bodied electronic type, at Holdens. Think they might be the only place with stock. This is an MG item, but exactly the same as the Stage pump so far as I can see. Not the cheapest supplier but better than being off the road. And Roger can get his spare back!

[martin]

Hi Wilf, as you know, the chimneys are aluminium and therefor soft, clean them out with WD40/petrol etc with a pull through, I wouldn't use an abrasive on them. then polish the steel damper tube with Autosol or similar, pop them back in with a drop of oil, then hold the chimney at about 45 degrees, the piston (air valve) should slide out. Martin.

[wilf]

Hi Martin, it isn't the pistons seizing in the chimneys, but the damper which sits in the ID of the piston, where you put the oil in to dampen.

[martin]

Hi Martin, it isn't the pistons seizing in the chimneys, but the damper which sits in the ID of the piston, where you put the oil in to dampen.

Note to self - improve reading !
Now that is strange ! Are the brass pistons still loose on their rods ? Could the rods be bent ? M

[milothedog]

Hi Martin, it isn't the pistons seizing in the chimneys, but the damper which sits in the ID of the piston, where you put the oil in to dampen.

Wilf, that may be damage caused by new sprag washers being driven in when the O rings were renewed, some Wet and Dry rolled in to a tube should clean out the ridges/damage.

Ian

[wilf]

Thanks Ian, that was going to be my next task.

Martin - yes, all looks normal on the dampers, this is an intermittent hang up.

[Jeff]

Hi Wilf,

Just got back from some friends in Duston and he said he saw your car and how good it looked. As soon as he said it had 'Buttercup' on it, I told him you were at Silverstone and a forum member.

Jeff.

[wilf]

It obviously looks good with the boot and bonnet lids up! Lol

[wilf]

Well, just a quick update on Buttercup's recovery.

The fuel pump was working but suspect, and anyway, taking it on and off 8 times last Friday did for the threads so it had to be replaced. Got one from Wards and now Roger's spare pump is on it's way back to him (thanks again Roger).

I replaced the float chamber needle valves with viton tipped ones as I suspected one of them at least was jamming closed. Unlikely I know but I am having to eliminate possible causes of a carburettor totally suddenly failing to, um, "carburett" one by one.

Next job will be to clean up the inner tubes of the pistons (where the dampers fit into) as I am pretty sure one if not both of those were jamming in the bores, probably against gouges on the bore walls caused by sprague washer renewal.

After that (and the last bit won't get done for a while due to other family commitments) if she doesn't run sweet again there will be a deal of head scratching.

Have to say it was pretty hot and sweaty in the garage tonight, a cool shower afterwards was never so welcome.

[wilf]

So, with the carbies back in place with nice new needle valves, and a nice new seal 'twixt manifold and pedestal, I took off the piston chambers to see what was what. There definitely was a random, intermittent hang up between the dampers and the inner bores of the piston that they move in. The trusty dremel came out, did some smoothing, and went back to sleep again. A thorough clean up with some spray carb cleaner and I put it all back together and, after checking everything was back and properly tightened, fired her up.

Once warm, all seemed normal, nice smooth tickover, disrupted by taking the oil filler cap off as it should be.

I even found the source of some occasional dampness in the V - loosened clamp on the top hose joint onto the thermostat outlet.

So maybe Sunday, when I get back from visiting my dear old Ma on the South coast, I can refit the air cleaner and road test her. Fingers crossed.

[wilf]

Buttercup is now fully back together and runs sweet as you like. Haven't had the chance yet to road test her due to other commitments, might try tonight!

I had to fit my spare throttle cable as the old one finally frayed too much at the end and made it impossible to get back into the solderless nipple.