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Messages - Crazy Mike

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Singles / Re: Care of petrol tank
« on: 11 January, 2021, 17:24:41 »
I read this topic with interest as, like Phil, I am in a similar situation with my B40 ('61).

The tank on my restored B40 has previously had expensive re-chroming and paint and looks great. However, inside it looks like there is a fair amount of rust build up which has prompted me to think about what to do to try and preserve it. I don't believe the tank has ever been previously sealed.

So many proprietary products for sale with varying claims! This is my first BSA (or older bike) and as such I have zero experience in de-rusting and sealing tanks so advice from those who have had success is very welcome. I haven't personally checked the price of having this done professionally but I think Phil's "ouch" answers that point !

Just for the present, is it best to completely drain the tank of petrol and leave with the cap on or off? Leave the tank on the bike or store elsewhere during this enforced period of inactivity ? My bike is stored in a dry garage.


Singles / Re: B40 wheel offsets
« on: 15 December, 2020, 19:28:19 »
Just checked RR Everything but the Engine.
The offset for 7" full width front hub is 3/16th "
Offset for C15 full width rear hub is 1/8 "
Hope this helps.

Singles / Re: B40 Silencer
« on: 15 July, 2020, 09:18:54 »
I purchased my fully restored '61 B40 last year and thought at the time that the exhaust was on the noisy side  but just accepted it as is. Earlier this year I needed to remove the complete exhaust assembly to remove the RH engine cover to check the small oil drainback 1/16 hole was not blocked.

After re-assembling and refitting the exhaust, for some reason the exhaust sounded much quieter and more 'normal' ! There was no previous evidence that the exhaust (which was new) had originally been wrongly fitted. However when refitting, I felt the exhaust needed a bit of a push to fit fully back into the exhaust port so maybe it hadn't quite seated properly when originally fitted.

Good luck and I hope the decibels reduce for you !

Singles / Re: B40 SS90 - still not right....
« on: 30 May, 2020, 19:46:39 »
Hi Bernie

Considering a recent experience I encountered on my B40, I wonder whether this may help ?

Inadvertently, I ran my bike with the ignition switch in the emergency start position and encountered exactly what you describe, misfire under load. This was soon sorted en-route once I realised my mistake. I wonder if during the re-build there may be a wiring / switch issue and the bike is running in the emergency start position ? (If your SS90 has emergency start, that is) Switching on the headlight whist on the road may give a indication if it's an electrical issue by adding more load thus potentially increasing the misfire.

Just a thought.. however, it could be one of many things, Perhaps the carb intake could be blocked with stray Goat's fur !

Good luck anyway.

Singles / B40 - Wet Sumping - Oil tank tap
« on: 06 May, 2020, 17:21:43 »
Hi All

After researching this Wet Sumping issue, I find this is more common and affects many older British Bikes, including BSA's. In an effort to minimise this on my 1961 B40, I decided to fit a valve tap which hopefully will reduce it's incontinence, save a bit of oil and keep my garage floor clean'ish.

I couldn't find too many pictures from others who have done the same so I attached 2 pictures showing the finished modification. I want to keep my B40 as near to it's original spec so I was in two minds about this but as it's turned out, it looks ok for me.

There are 2 parts I used. The valve itself is a 1/4" BSP male to 1/4" BSP female full flow ball valve and the second part is a 1/4"BSP female hose tail (8mm) which fits nicely to the flexible oil supply hose of 5/16" id. Total cost about 8 off t'internet. If anyone is considering this mod, I am happy to give details of supplier and part no's etc if you PM me.

 As a reminder to me to make sure I switch the tap on before starting the bike, I remove the ignition key and hang this from the new tap (providing I remember !)

Hope this may help anyone considering this mod.

Cheers !

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 04 January, 2020, 13:14:55 »
Finally, this morning I have been able to take the B40 out for a test ride!

As a recap, the revs intermittently, would not revert back to normal tick over and held at a uncomfortably high level. As a result of my investigations I can now strip and re-build a Monobloc carb in my sleep and having subsequently moved on to the ignition side, as recommended by many contributors, I can now report back with some good news !

Although the distributor had previously been completely overhauled, I was concerned about the presence of a lot of moly grease in the advance/retard mechanism. It just seemed excessive to me and this again, was supported by the views of various contributors. So, after cleaning the grease out, just leaving a light smear on the plates and adding a spot of 3 in 1 to the bob weight pivots I was hoping this would solve the problem. With the Static timing re-set, points at 0.015" it all seemed ok in the garage. The bike now starts easier with 2 or 3 kicks maximum. The test ride would prove it !

Well, I'm happy to report  that this sorted it out 100%. The revs now drop back to normal tick over with no hint of hesitance. The bike seems to run better. Hopefully for some time ! So, thanks to all contributors, I got there in the end ! let's have a look at that oil leak !!  (another post coming up I think !)

Thanks all

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 15 December, 2019, 14:51:44 »
Adrian, many thanks for  your reply. I think I will remove the distributor at some stage as you suggest as I can see it will make adjusting the points a lot easier. The cam drive shaft in the distributor does seem to have some play but at least the bike runs.

I've noticed that when running, if I twist the distributor slightly in a anticlockwise direction  the revs increase and fade in the other direction. Would it be correct to clamp the distributor where the revs are at the highest ? Where this is, the LT voltage wire on the outside of the distributor is very close (1/4") to the engine's cooling fins.

Just waiting for some decent weather for a road test !

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 13 December, 2019, 15:50:21 »
Following on from my earlier post, I have now 'discovered' a screw / bolt on the outside of the crankcase which, I now realise, is the distributor clamp screw !!!
I never really looked at this screw as I just thought this was another crankcase screw / bolt. Now it all becomes somewhat easier.
With the slightest turn of the distributor the bike now starts and runs. I still don't fully understand how the timing can change by just re-setting the points but hey-ho !

As for the uneven tick over, a road test will answer that in due course.

One question, now I have discovered the distributor clamp screw (cough-cough!) if I need to remove the unit, do I unscrew the screw all the way out or is just loosening it enough to presumably just withdraw the distributor from the case? Is it that easy ?


Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 13 December, 2019, 12:36:19 »
Adrian, thanks for your thoughts.

The points were 0.015" before removal and that's what I set them at after re-fitting so I don't understand why the timing should then be out.

To gain access to the distributor clamp screw on my bike involves removing exhaust, gear lever etc and then crankcase as there is no clamp on the outside of the crankcase which would have made life so much easier !

I agree with what you say about the cam drive plate as it can be fitted in 2 ways. The springs are in good condition as are the weights, as the unit was overhauled by the Distributor Dr in 2017 (300 miles ago).

Using the rod in the hole method with both valves open, I have checked the 1/16th BTDC and it looks like the cam is at the position to be just starting to open the points, so that looks ok. The weights pull back nicely if twisted by hand.

However, the only way I can start the bike now is by putting a washer under the spindle screw which clamps the cam and prevents movement. This surely indicates the static timing has changed , but how ?

I'm reluctant to remove the distributor if it's not necessary but would like to understand if and why the timing may have changed ?


Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 11 December, 2019, 17:59:00 »
I have now removed the points, condenser, springs, weights and cam plate and de-greased the unit as best as possible without actually removing the distributor from the crankcase.

I mentioned earlier about some 'scoring' on the underside of the weights. It look like the 4 raised rounded areas, as can be seen in the photo, may be the cause but I think they are there to reduce friction for movement of the weights, so it may be normal to see some markings.

The components, in my inexperienced opinion, look in good condition but I have two questions, perhaps  silly ones...

1) There is a screw which goes in the top of the rotor shaft, which I thought was there to secure the cam to the shaft, but it does nothing. What is it for as it doesn't secure the cam in any way unless I have a missing part !

2) I have not removed the distributor from the crankcase. Can I assume that the ignition timing will not be affected by what I have done so far ?

Thanks all.

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 08 December, 2019, 17:32:52 »
Thanks BernieJ
I will do exactly as you advise as soon as I can.

There is one thing I've only just thought of and it's when I removed the bob weights I noticed some 'scoring' on the underside of the weights. There are, what look like rivet heads, on the body of the distributor underneath the bob weights. I wonder if there's some fouling ? Once it's all clean I will be able to see.

Also, I assume that by removing the points and A/R mechanism, this should not affect the ignition timing.
Will report back once done and tested.
Cheers !

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 08 December, 2019, 14:26:24 »
Mike, the mechanism from throttle to carb is all new and the cable works as it should. The slide can always be heard to make a nice returning 'click' so I'm fairly certain it's not a carb problem. I'm really looking for views about the level of grease in the advance / retard mechanism of the distributor as seen in the photos.
I will take up an earlier suggestion to contact the Distributor doc for advice as well. Just for clarification here, the distributor is mounted on top of the crankcase.
Thanks for the responses.

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 07 December, 2019, 07:30:15 »
Dist 2

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 07 December, 2019, 07:29:40 »
Dist 1

Singles / Re: Uneven Revving B40 - Any ideas ?
« on: 07 December, 2019, 07:28:20 »
Thanks for the responses. I have checked the fuel cap and feed to the carb and all is well. Fuel flows freely so it's back to the Ignition.

Just a recap. The problem is the revs sometimes do not return to a normal tick speed. After much work on the carb I am now looking at the Ignition and in particular, the advance / retard mechanism. The distributor was completely overhauled by the Distributor Doc during the bike's renovation, this included new springs & weights and on first inspection it all looks ok (to me anyway). I decided to have close look and started to remove the points to gain access to the bob weights below and noticed what I think may be an excessive amount of grease (moly ?) which makes me think this may contribute to my problem.

What I don't know is, is this a 'normal' level of greasing. Perhaps the more experienced may care to comment on this and offer any other comments.
I hope to attach 3 pictures (if it doesn't work, I'll post them separately)
Dist 1 shows the unit with lower point removed
Dist 2 shows central cam removed showing weights and grease
Dist 3 shows weights removed

All comments gratefully received !


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