Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Mike40M

Pages: [1] 2 3 ... 7
Singles / Re: WD B40 front wheel sideways movement
« on: 22 June, 2022, 15:26:11 »
Checked on my B40WD. Spindle projects 5 mm from RH fork leg. Spindle projects 22 mm from LH fork leg.
If the problem is the thread in the RH fork leg, make a 4 mm thick washer to fit on the spindle. Could solve the problem.

Singles / Re: B31 - won't idle when cold
« on: 12 June, 2022, 07:56:11 »
Only one of my eleven bikes idles cold. A fuel injected Ninja. Have a couple of bikes with extended AMAL throttle stop screws that makes it easy to adjust idle speed.

« on: 08 June, 2022, 21:59:53 »
As said the Rupert Ratio books is a good source. Found them very useful.
The service sheets can be downloaded from

Singles / Re: B40 choke or not?
« on: 15 May, 2022, 06:10:54 »
When I bought the B40WD, it had a 376 Monobloc from a Triumph T110 and a choke slide that could not open fully. Going rich.  Removed the choke and plugged the top. No carb problem after the choke removal.

Singles / Re: adequate charging for a B40?
« on: 10 May, 2022, 04:30:45 »
My B40WD has more than 12.5V at tickover without lights on. On moderate revs it gives more than 13.8 V with lights on.  It's fitted with an A REG ONE rectifier/regulator. Surprises both me and Paul Goff that the old alternator is in so good condition. In my experience the Lucas alternators rarely charge the battery at tickover.

Singles / Re: Most suitable petrol for an M21?
« on: 13 April, 2022, 05:37:40 »
Useless information about paraffin. I have experience of both boats and tractors running on paraffin. You have to start using the petrol tank. When sufficiently warmed up, you can switch to the paraffin tank. A couple of minutes before stopping the engine, switch back to petrol so the carburettor is filled with petrol for next start.
Don't know if modern paraffin is the same as used in the fifties.

Singles / Re: Terminology
« on: 02 February, 2022, 06:30:19 »
A long time ago, a friend stated that when he had blown a J.A.P. speedway engine to pieces, he heard the engine gremlins shouting Free, free, at last free while running to the woods.

Singles / Re: Oil leak at front wheel
« on: 29 November, 2021, 17:04:28 »
Adrians advice seems a good starting point. If cleaned, you might be able to find where the leak is.
The drain plug washer or the damper washer as likely source of the leak. Not unusual with drain plug leaks if reusing the old one.
It should be easy to find out if fork seals are  source of the leak as described in earlier posts.
Checking the single side sealed wheel bearing can be done when you take off the wheel.

Singles / Re: Battery flat
« on: 29 November, 2021, 11:06:04 »
It might be that modern vehicles constantly draws current. Though some modern motorcycles can have a winter sleep and start in spring, other not.
Worst I have is a 2018 Citroen van that has to be run at least once a month to maintain battery charge. Even worse. some modern cars with flat or removed battery must be reprogrammed when fitting a charged battery. Also experienced that some of the modern electronic regulators we fit to our old bikes draw current. I now have the habit to take out the fuse on bikes not frequently used.
As Pete says, your Bonnie battery might need replacement. Or simply sell the bike and rely on the B40.

Edit: Batteries are best stored fully charged and cold. All chemical processes goes slower at low temperatures. A charged battery will not freeze. A poorly charged battery can crack at -30C. Happened to me.

Singles / Re: Taps for oil feed line
« on: 11 November, 2021, 23:27:59 »
Something that prevents starting with tap closed is strongly recommended. If you have roller crank bearings you might get more than 10 miles riding before a slight piston seizing. And not much cam wear. On a Vincent anyhow. Plain bearings probably just a minute before bearing replacement needed.

Singles / Re: Concentric carb experience
« on: 11 November, 2021, 09:02:21 »
Do the forceps compress the spring and hold it tight to the carburettor top?
Yes, the forceps grips the wire keeping the spring compressed up to the top. Makes it easier to fit wire and needle into the slide.

Singles / Re: Concentric carb experience
« on: 10 November, 2021, 23:11:06 »
Clamp forceps. Not perfect but works quite well

Singles / Re: Throttle stop screw (Concentric carb)
« on: 08 November, 2021, 07:14:20 »
I've done initial adjustment as Julian said without taking carb off by using a thin welding rod under the throttle slide. Turning the adjusting screw in until the rod can move free. Not certain if it works on a B40 where it's not much space to get a bent rod in.

Singles / Re: BSA M33 500 1955 Engine looses Power after 20 min
« on: 17 September, 2021, 21:35:39 »
Could be no tank breathing. Check if vacuum by removing tank cap when it looses power. Sometimes it can be that simple.

The 60W E3L don't give much at low revs, so it might be that your battery is draining with lights on. Especially with a 4Ah battery, which I think is less than the original. For a Norton WD16H which had been upgraded with an EL3 from the 40W E3, I fitted LED lamps some 5 years ago. Got no battery drain with lamps on at moderate revs. Back then LED lamp beam pattern was poor, but I'm told that there are LEDs with a decent beam pattern now.

Pages: [1] 2 3 ... 7