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Messages - LightningAndStarfire

Pages: [1] 2 3 ... 7
1
Hi, with the oil pressure gauge you can get some clues to whether the bush is in a good condition. If it is not oil pressure will be low. Let the engine reach working temperature and check the gauge. IMHO you should have at least 5 psi at idle and another 10 psi per 1000rpm up to 50-60 psi. Another cause for low oil pressure could be worn conrod big ends.

The -72 has the cast iron oil pump which is much preferred to the earlier mazak bodied.

2
Pre War / Re: vapour lock
« on: 27 May, 2022, 16:57:17 »
An infrared thermometer would perhaps be a sensible investment. You could easily measure the carb body temp and much more.

3
Triples / Re: R3 choke
« on: 27 April, 2022, 08:52:55 »
Hi, I assume you could put back the air slides without cables just to see if the stalling goes away. I think the stalling could be caused by something else. Did you manage to get the engine heat up? If so, any improvements?

4
Triples / Re: R3 choke
« on: 26 April, 2022, 09:55:14 »
Are you in need of the choke for your R3? Never used it for my Lightning, just tickle, start and drive away.

Would have been a successful cost-cutting to remove those air slides and mechanism IMHO, and BSA seemed to endorse cost cutting otherwise.

However, we are conservative blokes and are used to see that choke.
Cheers :)

5
Singles / Re: B31/B33 primary chain oil
« on: 21 March, 2022, 13:02:06 »
Excess oil will cause a loss of power when the clutch basket drags in oil. The oil will also heat up imho.

6
Singles / Re: B25S Should I Go For A Small Capacity Increase
« on: 11 March, 2022, 20:35:13 »
Please google "formula for compression ratio" .

Results seem relevant.

7
Singles / Re: B25S Should I Go For A Small Capacity Increase
« on: 11 March, 2022, 20:30:34 »
Yes, should have written cylinder head. Sorry.

8
Singles / Re: B25S Should I Go For A Small Capacity Increase
« on: 02 March, 2022, 16:35:45 »
Rupert Ratio has some info about big bores and compression ratios in his book about the Bsa unit singles. A very valuable book in general.

Often the cylinder is given a small adjustment to blend with the larger bore.

9
Singles / Re: B25S Should I Go For A Small Capacity Increase
« on: 02 March, 2022, 15:24:03 »
Your base is good, would be very interesting to know what kind of oil pressure you see if you proceed with a gauge.

I think the midel year -71 also had a cast iron oil pump, if you have that you are extra lucky.

10
Singles / Re: B25S Should I Go For A Small Capacity Increase
« on: 02 March, 2022, 08:34:42 »
Hi, what is the model year of your B25? IMHO it is of utmost importance to supervise the oil pressure in these engines (well, for all plain bearings engines) whether tuned or not. The later models are possible to fit with an oil pressure gauge and also have a strenghtened conrod. Another useful addition is an oil filter. Cheers

11
Singles / Re: Fork leg removal (1965 B40F)
« on: 02 February, 2022, 19:15:01 »
Some heat from a heat gun applied to the yokes could help. If you are not too concerned about the paintwork.

On my TRW250 the chrome top nuts were a bit shabby, I loosened them a couple of turns and with a sharp hammer blow on the nut the leg came loose without heat. Cheers

12
Twins / Re: New member 1st restoration project, ID this bike?
« on: 23 January, 2022, 12:14:15 »
A bike seeming very complete. Polish it up and running it would easily fetch 2000 pound sterling upwards. If you do not want it please PM me. Cheers

13
Twins / Re: New member 1st restoration project, ID this bike?
« on: 23 January, 2022, 11:00:16 »
The timing side has the clutch wire attachment which I think came on 1970 models. My 1969 Lightning does not have it. Cheers

14
Twins / Re: A65 running on.
« on: 30 September, 2021, 19:55:37 »
Perhaps a good idea to find out whether there are sparks from the plugs or a hot spot in the combustion chamber causing this. There used to be spark plug hats available with a window to observe if there is a spark in the lead, the idea is that there is a gap in the lead (with the window surrounding) for the charge to pass before the second gap at the plug.

15
Bantam / Re: D14 Runaway
« on: 14 July, 2021, 21:01:28 »
Hi, must be an air leak, through the seals or the carb, a worn slide or between carb and inlet to the engine. I would try a brand new carb, if the slide or the carb body is worn it could be worse when the engine heats up and some heat is transfered to the carb. Fuel evaporating has a cooling effect of course. A carb issue is more likely than the seals since air leaks through the seals would not give any additional petrol.

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