FH - weekly maintenance

 Just a little trip out this morning to pick up a part for the boiler from the Cromer plumbing centre. The bike is running very nicely and I managed to start it without the centre stand.

It's feeling a little bit squirmy so I decided to check the tyre pressures - the rear was a little bit down so we'll see what happens. 

I also put some tape and some marks to the throttle to help me set up the carburetion in the future.

This is the more traditional version of the Amal carburettor tuning chart showing us which elements of the carburettor affects tuning at various throttle openings:

Here is a more modern version, showing us a bit more detail and the overlap between the effect of the different elements:

Aside from practical adjustments like needle positions and the setting of the pilot jet, there are a few things we can change: 

• The main jet - available in a myriad of different sizes.
• The slide cut away - various sizes are available both larger and smaller.
• The needle. Most four strokes used the same needle, but there is a 'lean running' needle (part number 104) which is longer and thicker and clearly allows the engine to run with less fuel at higher RPM.

As the engine gets closer to being run in will be able to do some plug chops to determine the mixture at various throttle openings. At the moment, with only 138 miles on the clock what we can do is quite limited but I think we can look at perhaps the first half of the throttle opening range.

FH - finished!

 Well this is it, I am calling the Huntmaster project finished. In the last post which I wrote yesterday, I fitted the wheels and brakes and tightened up everything in that area.

Today it came off the lift to be replaced by the Square Four and rolled out into the yard for some pictures. 

The yard is halfway up a hill and when I was happy with the pictures I togged up with helmet and gloves and rode it up the road to test the brakes. I've set the tyre pressures to 28 & 36 psi, on the basis that the weight is more or less the same as the SQ4 - though the distribution might be very different - and it's using the same tyres, albeit in different sizes. If nothing else, it's a good starting point.

Several round trips later, each interspersed with some brake adjustment, it was time to take a cup of tea to Mrs H at her allotment. Domestic bliss waits for no man!

Hopefully tomorrow, we will have some time to go a little further.

SQ4 - New tyres

One of the things I have always admired about these old machines is the ease with which you can remove the wheels. OK, so I do have a QD rear wheel on the SQ4 and the W/NG is a little more difficult but at least I have two stands and can remove both wheels at the same time! Try doing that on a modern bike.

Something that is less impressive is the front brake cable adjuster, which doesn't fit any of the toolkit spanners - it appears to be 2 BA across the flats, but it is a pattern part so perhaps that is the reason. I have a 2 BA spanner in the toolkit especially for it.

The front stand is very useful, though you have to lift most of the engine weight to use it. The trick is to make sure it is slack enough to swing down, and then tighten it up again.

The reason for all this was that the Avon Speedmaster & SM MkII tyres are now 9 years old and it's time to replace them. I've bought a set of Avon Roadrider MkIIs, just like I put on the CX500 back in 2019.

I might tackle that damaged paint on the brake drum before they go back on. But then again, I could just as easily do that when it was on the bike and get riding it again!

For the record, I am running these at 28 psi and 36 psi, at least for the moment.