FH - engine sprocket

 With Mrs H on the couch, asleep after a busy morning on the allotment I decided to do some shopping and on the way back get a bit of time in the workshop. After finishing measuring all the timing cover screws I decided it was time to change the engine sprocket.

Regular readers will know that I realised after riding the bike that the gearing was very low, and inspection of the pictures revealed that I had a 22 tooth engine sprocket: for solo use, I should have a 24 tooth engine sprocket. The Siamese pipe that came with the kit is another clue to the bike's history with a sidecar!

Pulling the primary case apart is a pretty straightforward exercise, if messy. I thought the case was empty of oil, assuming it had all been thrown out - in fact, the drain hole was blocked with red Hermetite and removing the plug had no effect - so it all ended up on the bench...

The primary chain has 74 pitches. A lot of adjustment of both chains had the gearbox in a suitable position for the new sprocket to go on. Note to self - for the future, using a socket and the slim plastic 3/8" ratchet drive on the primary chain adjuster makes it relatively quick to move the gearbox. 

Here it is in place:

I noticed that at some point in the dim and distant past the primary chain must have got very loose because the cast lug for the primary case screw right under the sprocket was very worn to the extent that oil would leak into the screw hole. I refitted the screw with a fibre washer. Incidentally, rather than use the large gasket with Wellseal I sealed the primary case with Threebond 1215 and no gasket.

These things are so easy to work on. I'd been considering whether to tackle this job before I rode the bike again thinking that I didn't want to have it off the road for too long but actually this kind of thing only takes a couple of hours. I hate to think how long it would take on a modern bike - but then you probably wouldn't have to do it in the first place! 

That's it all back together again a couple of days later:

FH - timing cover screws

 The Huntmaster timing cover has three different screw lengths which are not at all obvious - except for the short ones - if the screw holes are full of goo. 

I have cleaned out the screw holes with a twist drill and recut the threads with a long series 1/4" BSW tap so I know that they are in good shape. However the difference between the so-called medium length screws and the long screws is only 1/8" - so it's quite easy to get them wrong.

This afternoon, worried that a mix up of screws was leading to timing case leakage, I pulled them all out. I measured the depth of each of the holes with the vernier caliper and marked the relative depths on the timing case. I took this picture:

Now I have a good record of where the screws go. As it happens they were all in the right places.

FH - points

 Just for the record, I have used the on-board points spanner (with built in 12 thou feeler guage) to determine that the point gap for both cylinders is identical.

This means the ignition timing should be similar on both cylinders.

The lock nut for the fixed point needs a 8 mm spanner, which I've added to the toolkit.

FH - shaking down 3

 Well, the mild spitting and reluctant starting returned with a vengeance today. After the tank pinhole repair, the washer around the speedo cable and some general bolt tightening I fueled up and took the bike for a short commute of about 4 miles.

It was certainly reluctant to start, and was also lumpy as hell but it got me there and restarted when it was time to come home.

The journey back got progressively worse, and by the time I turned into town I had only one cylinder.

That cut out as I turned into the yard.

The engine sounded flat and 'hard' on the way out, just like the W/NG when it's retarded. The blue exhaust pipe in the picture screams 'retarded' too - the bike went straight on the ramp when I got home.

With the plugs out, I engaged top gear to use the back wheel to turn the engine with the magneto end cover off - the points had virtually closed up. Setting that back to 0.012" had the engine bursting into life at the merest tickle of the kickstart!

I greased the point cam, but I must check the gap on both cylinders.

Shame about the blue exhaust. That won't polish out but at least the tank isn't leaking!

FH - speedo cable

 After a suggestion from AOMCC member Stan, I've put an O ring around the speedo cable in an attempt to stem the drip of oil on the cable...

There's a fair bit of oil under the timing case, which might be coming from one or both joints or might be flowing down from the oil pressure regulator valve. There may have been no leak down the speedo cable, since oil can drip from the crankcase/timing cover onto the speedo cable...

FH - small repairs

 Spring is here and I'm away using the Square Four for some little house renovation jobs in a nearby town. There's a little bit of time in the workshop to do a few bits on the Huntmaster. 

We'll start with blocking that hole in the primary case that used to be used for the chain oiler before the fully Enclosed Rear Chain Case arrived. It's lost its blanking plug so I've made a new one up from a cheese head 3/16" BSW screw with a fibre washer:

The next one is a bit more serious. This is the pinhole in the fuel tank - I've taken the tank off for better access which is quite easy with these single centre bolt tanks. I've opened the hole up a little bit to clear the paint with a scriber and I've cleaned the area with acetone.

I've put a blob of Seal-All in that hole - just a tiny blob. After deliberating for a while over the approach I would take to this repair I realised that Seal-All had been sealing several holes in the W/NG tank for many years, and is still good. We'll see how this turns out tomorrow.

FH - shaking down 2

Well, I expected to do a few modifications or repairs after a bit of shakedown mileage - for example I now know that it needs a larger engine sprocket and I've got a couple of oil leaks - but I didn't expect to be taking it off the road quite so soon! I fully filled the tank for the first time yesterday having driven around with about a gallon sloshing about in the bottom for the last few miles and unfortunately it appears that the extra weight of fuel has revealed a pinhole. Now this tank has had a few weld repairs, it's been tested with air several times and filled with Slosh sealant - but there's still a pinhole.

You can just about see it here - there's a bit of a 'halo' around the hole. The tank is empty in this picture - with 4 gallons in there, it drips constantly.

Would something like Petro Patch work do we think? JB Weld perhaps?

In other news, fellow AOMCC member Stan has been in touch to tell me that BSA engine sprockets (A, B and M series) will fit and I have ordered one; I'll put a 3/16" BSW cheesehead screw in the open chain oiler hole in the outer primary case, because of course this hole is not used on FERC bikes and just provides a leak path. Stan suggested a couple of other things:

• Use Morris AG90 gear oil in the box
• Put an O ring under the speedo drive nut to stem the cable oil leaks
• It's worth getting an aluminium gear for your auto-advance unit as a backfire can strip the fibre teeth
• It's worth having a spare rocker shaft in your toolbox as these can break

You get great support in the AOMCC.

I did check where the idle screw had ended up after the hot adjustment yesterday - 1 1/2 turns out. However, starting today was a bit tricky - the bike was more reluctant to run. I had the choke fully on, perhaps the weather was too warm? It was spitting back a fair bit.

I've also ordered a new fuel cap.

FH - shaking down 1

 Well, I've decided that since in the last nine miles of circuits around the house the Huntmaster hasn't exploded, I have today filled it up and racked up another 15 miles.

Amongst other places, we've been to the lovely 1901 Weybourne Station on the North Norfolk Railway. Here the FH poses next to the 1960 - built English Electric Class 37, ready to depart on the last up-train of the day.

It's going very well. In the first nine miles I had adjusted the brakes 3-4 times, and after changing one of the levers they are starting to feel OK. 

Some days ago, I had adjusted the tickover. Today, having put perhaps 11 miles on the engine I stopped at Weybourne to find that it was less easy to start; adjusting it on arrival at home, I leaned it out 1/2 turn or more - the plugs are showing tickover was rich. I may have gone too far, but before I adjusted it the engine was very easy to start cold.

The other thing that is obviously wrong is the gearing - you can feel it is too low. Inspection of the build pictures show there's a 22 tooth engine sprocket fitted - standard fitment for solo bikes is 24, so we will have to see if we can get one of those.

Lastly, we have a timing cover oil leak and a primary case oil leak. I know that the old chain oiler screw hole is open, and there may well be too much oil in the primary case but since that will have to come apart to fit the new sprocket, we won't worry too much. The timing case is another matter.