Saturday, March 20, 2010

Broken bolts/studs?

There are various ways to remove them and this turned out to be an exception to the normal rule.  Usually we are stuck with a seized thread, due to corrosion, and the fastener duly snaps off in the engine, frame or whatever.

Now this particular bolt wasn't seized, but its thread was damaged and it wouldn't attempt to unscrew.

The easiest thing to do was cut it flush and drill through it.

So, armed with the necessary, a centre pop in the middle of the stud, a small drill bit (3.5mm) for a pilot hole and we were away.

The idea when drilling through a stud is to be dead centre and continue that way!  If this was in a cylinder head, or equally important part, I'd be a lot more careful. 

 As it happens I went off at an angle, but this proved to be to my good fortune!

The stud could now be closed up with a Vice Grips and popped out of the frame with a punch and hammer without any further damage to the frame.

An 8x1.25mm tap to re-cut the thread.  There is a good chance that it's too far gone for this and may need a thread insert fitted, but it's worth a try anyway.

Yes, the thread is too far gone for my liking.  The bolt will screw in but has a touch too much play.  It would work for a while but will strip at some point.  Time for a Recoil kit and the next blog post.

Tuesday, March 16, 2010

Seat Covers, Bases, Rust and Ruin.

I ordered a new seat cover off Ebay because I just happened across it ,and thought I'd better snap it up (that's me all over!). I'm certainly nowhere near that stage yet but at the end of the day - it doesn't matter what you do first.

But maybe I should have had a better look at the seat before splashing out on a new cover!

Time to get the old cover off and check that seat base.  Looking a little corroded!

The staples are very rusty but, with gentle leverage, came out of the plastic strips that are rivetted to the seat base.  Any sharp bits left were taken out with a long-nosed pliers.

So, as the cover came off, the donkey was able to see the carrot.

Unfortunately, the base was worse than I first thought.  Not impossible but it might be better to source another seat rather than try and repair.  I'll have a think about this one.

The foam, which I thought was in bad shape, didn't turn out to be too bad.  A good wash and I think it's reusable.  Yes I'm serious.  It's still nice and soft and the rough sections shouldn't show once the seat cover is fitted.  I've seen worse.

Sorry if you thought that there might be a shiny new seat sitting at the end - that's how it goes sometimes.  Half the battle when restoring bikes is maintaining the motivation when the rust crumbles in your hands - oh, and money, money's always a problem!

Spend time thinking about the solution - not the problem.

Saturday, March 6, 2010

The Carburettor: Bing 84

Anyone who's tried to strip an old carburettor will know of the hardships involved: blocked airways, damaged screw heads, seized jets.  The state of the outside didn't bode well.

Nevertheless, it needed to be cleaned - it needed to be stripped.

Using a mixture of WD40, soapy water and carb cleaner, I managed to get the outside clean enough to work on.

The quick release clip for the float bowl moved with ease. 

A few taps with a screwdriver handle to separate the bowl from the cork gasket and it was off.

It wasn't pretty but I set to work with the carb cleaner and screwdriver and it began to clean up really well.  In fact, the float bowl is in superb condition compared to my military 250 Can-am.  Having sat in a pond for years, the military version's had begun to rot out.

The float pivot slid out like a new one!

The float needle - looks in reasonable fettle to be fair.

Like a bought one!

The entire carb came apart as if it was put together yesterday.  Not bad for 35 years old.
Take note of every jet, spring etc.  Easy to lose parts so take your time and keep your work area clean.  When unscrewing jets, use a quality screwdriver that fits the slot properly.  Brass jets are easily damaged but I'm pleased to say the pilot jet was in superb condition.

If you have access to a compressor, blow out all of the airways/jets and check that the air is passing right through.
The only thing I need to get is the tickler mechanism as it's rotted slightly.  I'll finish the cleaning/polishing when I fit it.

Wednesday, March 3, 2010

Vinegar - one week later.

I wasn't sure what to expect.  The vinegar was definitely doing something because the colour had turned dark brown (the rust magically dropping off?).
So, a quick wash off in water was in order.  The parts were coated in a grey/black residue which needed washing off and a quick rub with a wire brush.

The pliers will rust quickly after being in the vinegar so wash them, and WD40 them, straight after.

The next step was to tidy the threads up using a thread chaser kit.  A tap and die set would also be fine for this but I didn't have a large enough die.

This is a great kit - not that expensive either considering it's Snap On, and it has got me out of a lot of trouble over the years. 
It has slots placed within the thread of the "chaser" nut so that any swarf cleaned from the threads can stay away from the bolt, preventing further damage.

You can see the slots more clearly here on the tap version.

I'm pleased with the results.  Not all the bolts have come up to this standard but I'll perservere and replace only the parts that I need to.

Monday, March 1, 2010

Progress - removing the flywheel.

At last, things have started to move on the bike.  Well, slightly - I've been taking it apart and cleaning the odd part.
The corrosion under the generator cover was quite intense.  I had a puller for the flywheel but it wasn't even going to attempt to start on the rusted thread!  Time for a Dremel  with a tiny wire brush - it worked a treat.
A puller is a wise investment.  I've damaged flywheels before when thinking a lever and a sharp tap to break the taper is enough to remove it.  It doesn't always work and one damaged flywheel is worth a lot more than a puller.
So, with thread nicely cleaned, it was time to see if it would screw on.  Plenty of WD40 and slight persuasion and it was soon screwing on easily. 
Ideally you need it to screw on all the way.  It's very tempting to get it on a couple of threads and try to remove the flywheel, but very often this will strip the vital first threads.  Persevere until you get it on properly, then tighten the bolt in the middle before applying a sharp tap with a hammer.  This is how you "break" the taper.
Tighten the bolt in the middle again if the flywheel hasn't dropped off.  Then apply another sharp tap.  Repeat the process, always tightening the bolt, until it releases.
And there we have one undamaged flywheel.