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Messages - Steve.S

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Singles / Re: M21 rebore
« on: 05 May, 2024, 12:34:12 »
If it were mine, I would have it resleeved back to standard.

Pre War / Re: Carb re sleeve
« on: 05 May, 2024, 12:32:14 »
The slide is 1 3/16" diameter.

Pre War / Re: Missing screws
« on: 05 May, 2024, 12:31:12 »
Surprisingly, they are 1/4" BSCY and the outer ones are 1 1/8" long.

Well, is it much easier to kick over when it won't start compared to normal? If it is, then it could be the exhaust valve sticking. Make sure the valve lifter is not holding the valve open. 75lbs sounds a bit low for 6.5:1 compression ratio. Is it gutless? I would expect nearer 100lbs or more. You  should add a little oil through the plug 'ole and see if the pressure increases. This will seal the rings temporarily (and to a degree the valves). Ideally you should carry out a cylinder leakage test, but the kits cost about £100.00. However I think this is separate to the problem you have.
So from what you have said, I would suggest possible magneto failure (which probably means it's the carburettor!)
It may help if you took a neon with you to fit when it won't start to see if you have a spark.
Regarding Lead Replacement Additives, it could be argued that the valve seats would have work hardened by now, so being unnecessary, but if you select one with an octane improver, you may be able to run more ignition advance before pinking sets in, giving you a little more power. I would recommend using the Castrol product.

Pre War / Re: Missing screws
« on: 04 May, 2024, 21:10:45 »
I think you will find that Hitchcock's Motorcycles sell a set of 10 Timing Cover screws with the correct fillister head and thread. The Part No. is 90209.
You will have to cut them to length. They're rather expensive, but they do look the part.

Pre War / Re: B21 gearbox gaskets
« on: 04 May, 2024, 16:42:08 »
I would think about 0.010" to 0.015" thick. But remember that the thickness will affect layshaft and mainshaft endfloat. If excessive, this will result in a poor gearchange.

Pre War / Re: 27-1055
« on: 04 May, 2024, 16:31:46 »
Can't be much help I'm afraid, but in the absence of the correct part, if you have a lathe it would be quite easy to make one.
If not, perhaps you could get a 3/8" BSCY bolt and drill and tap the end to accept the cable stop, maybe with a spacer to line it up with the lever.

Pre War / Re: 1932 BSA Blue Star speedometer
« on: 12 April, 2024, 13:42:21 »
These gears are available at Cornucopia.

Pre War / Re: 'B' series girders
« on: 10 April, 2024, 02:02:05 »
I've just had another thought. If you scrape away the paint from the outside of the links, you should be able to see the BSA piled arms stamping of 3 rifles leaning up against each other. Above this should be a letter. This will indicate the year of manufacture. Hope this helps.

Pre War / Re: 'B' series girders
« on: 09 April, 2024, 19:00:19 »
It's difficult to say, because forks of this design were fitted to all BSA models up to 1936....all different sizes.
My guess is that they are from a BSA B1, B2 or B18 forerunners of the B21.
In passing, the link pin hole in the forks look oval to me, but it may just be parallax. Otherwise they look in magnificent condition and well worth having done professionally.

I wonder if you might have more than one problem here?
Firstly, I've found that failure to pick up from idle is caused by a very weak mixture, often due to either the pilot by- pass jet in the jet block, or the pilot jet in the carburettor body being  blocked. You could check these with a can of WD40 with an extension tube fitted. It could also be due to a badly worn carburettor. Open the throttle slightly and see how much play there is in the slide.
The other thing I would do is remove the fuel pipe from the float bowl, and see what flow you have through the pipe with the filter fitted. It may be frustrated.
The next time you go out, take an HT Neon with you. Then, when it won't start, you will at least know whether or not you have a spark.
You could test the magneto yourself if you had Spark Gap Tester. If the spark jumps a 5/16"gap, that would indicate the magneto is producing 15,000 volts. You could also heat the magneto with a hot air gun to see if you still had a spark.
I think you said in a previous post, that if you held the tickler down, the engine keeps running? Perhaps your float is sticking up intermittently? If it's a Monobloc, you could try it with 2 cover gaskets. I believe you've already tried running without the fuel cap fitted?
Finally, when it won't start, remove the spark plug to see if you've flooded the engine.
Let us know how you get on.

Pre War / Re: 'B' series girders
« on: 09 April, 2024, 16:00:41 »
I wonder if there may be some confusion here? If your Parts Book shows bushes, then the forks and links should be as Ron describes.
However, if your forks have links as in your photo, then these are earlier forks and the pins ran direct in the forks without bushes.
You will probably find that not only are the pins worn, but the forks are worn oval. There's not much metal to bore out the forks to fit bushes.
I believe specialists bore out the forks and fit thin wall bushes, cut off the pins, make and weld on new ones. Of course, this has to be done very accurately, otherwise the forks will bind. You may want to talk to Jake Robbins.
Otherwise, if you're a bodger like me, you could just put them back together with shim stock and water pump grease.

Pre War / Re: Electrical Issue
« on: 29 March, 2024, 16:44:33 »
I think you are worrying unnecessarily about the speed it turns. Just be sure it rotates in the correct direction. Then do the test with a bulb Ron suggests.
It should get brighter with revs, and if you overdo the revs the bulb will go pop. Some people use a short piece of rubber hose and a couple of jubilee clips to provide drive from a drill.

I've just re read your original post. If you disconnect the pipe, I'm fairly sure oil won't pour out, or be free flowing. But it should certainly be a fast drip or trickle.... depending on how cold the weather is. I use 50 grade oil. Do you know the year and model of the bike?
Bear in mind you will only see oil dripping regularly into the pump with the engine running, and I'm not sure they work without the glass fitted.

Oil should definitely come out of this pipe. Originally, there would have been a tap fitted to the tank. Have you turned it on, or is it blocked? If no oil is coming out, the engine may blow up. So don't start the engine.
It's essential to be able to see the oil dripping through the pump. The "glass" was originally celluloid, but you should cut a new one out rigid thin plastic sheet.
A good starting point for adjustment is 1 drop every 4 seconds.
Once you have the oil flowing, it might be worth draining the crankcase, as a build up of oil will cause bad starting and a smokey exhaust.
Finally,  you might get a better response if you posted similar questions in the Pre War section.

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