FH - Engine bottom end

 While the painted parts are away, I've got the engine on the bench. Way back when, I established the state of the bores, mains and big ends and what I want to do now is to trial fit the new large bearing crank into the original cases.

A little while in the kitchen at home saw the main bearings fitted:

It's then no more than an hour's work to assemble the crankshaft and the timing gear; the good news is that the timing gear bushes already in this case are in very good condition with very little play. Shame I already bought a new set.

It was clear that the crankshaft was a bit tight. The setup with the DTI reveals no end float and the crankshaft was mildly stiff to turn, but then it does have a large plain bush at one end:

Investigation revealed that the drive side bearing wasn't fitted fully home against the crankshaft web. With that fixed, we have 0.34 mm end float:

That's about 0.013"; we want a maximum of 0.005", according to BSA Service Sheet 208 - Waller is silent on the subject. Since 0.005" is 0.13 mm, we need to shim 0.21 mm; I've bought 0.25 mm shims which should give us 0.09 mm end float, or 0.003".

More later when bits arrive.

FH - Prepared for paint

Here are the pictures of the Huntmaster bits that I'll use to catalogue the bike for the painter:

VMCC Castle Acre Run

 Sunday dawns and I'm up early to get to the start of the Norwich & District VMCC Castle Acre Run but first, it's a trip on the W/NG to deliver the TS125 tank:

With the tank back on the MZ, son Tom starts the freshly oiled & fuelled SQ4 that he will ride today. I'm on the modern Interceptor, just for a change. 

First stop is at the start of the run, for tea, a chat and to sign on. Lovely barn conversion and outbuildings:

At 11:00, we depart for the 37 mile trip to Castle Acre, following the Tulip route sheets. I make the mistake of relaxing at the back of a line of two bikes who miss a turn and I have to double back, messing up my calculations. We arrive eventually, and I'm not last, though I expect to find Tom and the SQ4 there already. He's not, and it turns out he's stopped to wait for me, witnessed by the missed calls on my phone. He turns up a few minutes later and we have lunch.

Two portions of loaded fries and a chat later we wander out to look at the bikes, and do some more chatting...

The rest of the section will take another 37 mile run back to the start, but since that would be in totally the wrong direction for us we say our goodbyes and head back to North Norfolk.

Totals for the day - 130 miles for me aboard two different bikes; about 100 of those on the Interceptor. The SQ4 is going really well and uses negligible oil, and consumes fuel at 50 mpg!

Have to take it a bit easier next time.

Charlie's Shed - Lining a petrol tank

Regular readers will know that in the past few months I have made weld repairs to two petrol tanks, one of which still has a weep in a very inaccessible place.

Today I'm going to line the tank with Slosh, from Rustbuster. This is a polyurethane sealer, resistant to Ethanol, that cures in air. I've cleaned this tank already with their SP10 Tank Kleen and a selection of nuts and bolts:

Those bolts came out a lot cleaner than they went in!

The sealer comes in two bottles, for two coats. You have to pour it in, rotate it around, wait twenty minutes and repeat twice more.

You let it drain from the tap connection to avoid it pooling in the bottom of the tank.

The reason you don't want it pooling is that it gases off a little when setting, and you don't want voids in the lining:

Three hours later, or when the sealer is dry but still tacky, you do the second coat in the same way. Then you let it cure for five days. Easy peasy.

This 400 ml kit is supposed to be sufficient for a 10 gallon tank, and I'm sure it is. My plan was to seal both the MZ tank and the Huntmaster tank in one sitting, but obviously two tanks have a greater metal surface than one tank (though the two together totalled less than 10 gallons) and I wasn't confident I'd have enough for both, so I ordered some more sealer for the FH.

Now that son Tom has his MZ sparking, he's clamouring to get his tank back...

Charlie's Shed - Points backplate

A plea on the VMCC forum found me a little job this week - local BSA B33 rider Richard was looking for a new points backplate - the old one had a stripped hole at the contact set clamping screw.

I volunteered to help - I do this sometimes, it’s a good way to meet new people, it costs nothing and it’s always nice to practice one’s skills. A quick Google revealed that while you can get contact sets, caps and condensers for these ‘distributors’ - Lucas 18D2 or similar, used by BSA, Norton and Royal Enfield the backplate is not available:

The 2BA hole had no thread left and the screw was in a bad way too. I started by marking the hole position on the back, with a scriber:

Laid on the usual copper bar heat sink, I set the TIG welder to 35 A and filled the hole from both sides.

I ground it flat with the Dremel and a file, drilled it for tapping 2 BA (4 mm) and recut the thread.

I cleaned it up with a wire brush. It took a bit of Googling before I was sure I had it assembled correctly:

Having delivered it back to Richard, and seeing his lovely B33 which he has owned for 16 years I was pleased to learn it started straight away. I must have assembled it OK!

It was great to find a few beers on my doorstep the next day. That’s the kind of fee I like.

FH - swinging arm trick

 Ariel PRF frames have a close fitting swinging arm that looks like it comes out backwards.

It doesn't, because the curve of the frame tube gets in the way:

The trick is to push it forward - this obviously only works if the chain guard and oil filter, and the rear mudguard, are already removed. 

FH - it's coming apart!

 I think all this post is going to do is perhaps convince readers that I am actually doing something. It's coming apart for painting. 

FH - Petrol tank dent repair

 I know I know I know... this bike build has been going on far too long, but in my defence I do have a lot of stuff on. Recently, apart from the puncture I have been faffing about with a press stud on the W/NG panniers, had the carburetter float bowl apart (I must fit a finer fuel filter, the bowl is full of debris and it's stopping the float valve seating), welded up an MZ tank etc. etc...

After several weeks of trying to pull a massive dent out with stick-on dent pullers - I event tried soft soldering one on - I decided the only way I was going to get the dent out was to cut it out, bend the material back to shape and weld it back in. Buoyed with confidence from the MZ TS125 tank, which came out with only two pinholes I decided to go forth with the little Dremel discs:

These discs are one of the best things Dremel make, and the panel was soon out:

Using a variety of tools, including home-made bending irons, adjustable spanners and hammers I adjusted the body of the tank and the panel I had cut out to match a template I hade made from the good side:

I've bought a variety of strong magnets over the years and held the panel in place for tacking:

The plan was to minimise distortion by making short 1/2" welds and letting them cool before moving to a different area, building up the full peripheral weld in short, cool bursts. I started with six-seven tacks:

And ended up with a fully welded panel:

This was dressed back with the Clarke power-file - a 1/2" belt sander, which is proving to be a very useful tool. Next, I closed off the filler neck with duct tape and attached a cycle pump to the fuel tap:

Result! Two small pinholes, fixed in seconds:

Next, Slosh sealant - to ensure an expensive paint job isn't going to be ruined with a fuel leak.