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Messages - Dabbist

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1
Singles / Re: B40 Silencer
« on: 21 May, 2018, 16:23:58 »
Mine has a perforated tube running through with absorption packing around it. I haven't heard it yet (still in lots of bits) but I've used a similar design on other bikes. Not quiet, but takes the edge off and softens the sound a bit. You can buy perforated stainless tube and the wadding on line, so maybe you could modify it yourself.

2
Singles / Re: Primary chaincase oil
« on: 16 May, 2018, 18:20:30 »
Rupert Ratio does suggest a breathing mod for B40s which results in them sharing the engine oil and primary drive oil, so one must assume that engine oil is fine.
 Thumper's right though. The oil can play havoc with the clutch. I've been through all sorts of options on trials bikes, trying to stop clutch drag. I've used both ATF and engine oil successfully. My Cub's running on a 10w40

3
Singles / Re: Need help with my BSA Shooting Star not starting
« on: 15 May, 2018, 13:08:27 »
This sounds too complicated to me. Very little tends to fail while doing nothing. Both my trials bikes (one Beta, one Cub) can be difficult after a layoff, but  both respond to a new plug and fresh fuel. I know both have been mentioned, but I havent seen confirmation on the fuel side. Modern petrol goes off very quickly and can make all the difference.
I don't think you mentioned whether the plug was wet after you kicked it over, if not then  definitely clean the carb. Fuel depositing a layer of "laquer" does happen when standing, so must be high on the list .
Nothing new here, but hope it helps

4
Singles / Re: B40 Star air filter - what's the best option now
« on: 07 May, 2018, 22:12:13 »
Hoogerbooger, I know this is a late response, but I have a centre panel with the air filter in place. Since I'll be fitting a different carb anyway I'd be happy to exchange my centre panel for one without the air filter.

5
Singles / C15 centre panel
« on: 07 May, 2018, 22:02:49 »
My B40 has a C15 centre panel ( the one between the oil tank and the tool box) which has the original air filter welded in place.
I understand that complete ones are quite hard to find. I don't intend to use the original filter, so if anyone has a decent b40 centre panel ( exactly the same but without the filter) I'd be happy to do an exchange, otherwise  i'll just remove the filter, which would seem a shame.

6
Singles / Re: B40 fork seal holder string seal
« on: 06 May, 2018, 19:48:34 »
Thanks gents. Looks like ptfe is the easier option.

7
Singles / Re: Oil filter
« on: 06 May, 2018, 10:30:39 »
I'm in the process of fitting a spin on canister filter kit (same as the Norton Commando one) to my B40. The whole kit is about £20 And it seems to be a highly recommended mod.

8
Singles / Re: 1966 c15 sportsman
« on: 06 May, 2018, 10:23:11 »
If you really want a better brake (And who could blame you?) You could fit a set of B40 heavyweight forks (I suspect you'd need the wheel as well) to which you can fit the 7" tlr  brake. RR says it may need some material removing to clear the fork leg, but mine goes straight in.
Most people would be pushed to tell the difference in the forks.

9
Singles / Re: C15 Front hub spindle
« on: 06 May, 2018, 10:12:06 »
Rupert Ratio suggests a starting point of 1/8" for a C15 full width front hub (And the same for the rear) but does recommend a final adjustment with it in the forks.

10
Singles / B40 fork seal holder string seal
« on: 06 May, 2018, 10:06:03 »
Hi All,
           While stripping my b40 fork sliders, I found there's a "seal" of twisted string around the bottom of the thread for the oil seal holder. I haven't seen any anywhere and can't quite figure out how to twist it in place tightly enough. Has anybody out there made them (if so, how)  or would a big "O" ring do the job?

11
Singles / Re: Oil return tube
« on: 29 April, 2018, 19:26:01 »
I guess if you're concerned about it you could always disconnect the oil return line from the tank and squirt oil down it. If it doesn't come out at the bottom (and you get oil back into the tank when it's running) then your ball must be in place and doing it's thing.

12
Singles / Re: Oil return tube
« on: 29 April, 2018, 14:13:25 »
Ok, the confusion is my fault. Which is what we get when I try to work from memory. Sorry about that. :-[
 The second pipe was always there (mine's a '62) but they changed the square sump plate part way through, putting a second hole in the filter for the smaller pipe to pass through.
That pipe is where the pressure is relieved to, the "feed" to the pressure relief valve being the big end feed . I confess that I'm not sure why they bothered with the pipe, without it, it would have just vented into the same space anyway.

13
Singles / Re: Oil return tube
« on: 29 April, 2018, 12:47:34 »
That sounds fine, with the cases split you can the line of the oilway from the relief valve to the sump.

14
Singles / Re: Oil return tube
« on: 29 April, 2018, 11:33:26 »
I'm not sure whether your sump plate is rectangular, or square and just looks off from the angle of the photo. The later engines  had a second pipe into the sump which came from the pressure relief valve. These were the ones with the square sump plate.
I believe the transition was around '65, but BSA were infamous for introducing changes based on what parts they had, rather than precise timing. I've no idea whether there was any crossover, though.
I'm guessing somebody on here will have more knowledge than me and be able to identify which yours is.
I have my (early type) oil pump on the bench at the moment and can't really feel the ball bearing at all when I shove a small drill bit up it. I can see it and I can hear a tiny "plop" as it unseats, but I probably wouldn't if it were in the engine.

15
Singles / Re: B40 Alpha main bearing conversion
« on: 28 April, 2018, 11:02:23 »
Here's the explanation from Alpha
"We estimate how much the crankcase might reduce the bore of the outer race and trust that after fitting the retained clearance is adequate.  This is an industry standard practice and in roller bearings denoted by “C” values.  (Since we are normally expecting our components to be fitted to machines over 50 years old the expectation is that the crankcase to housing interference will not be excessive and most customers do not need to hone the outer race.  We suspect your crankcase bore is better than most other customers’ hence the issue with your cases)."

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