SWM Electrics

Though I’d blown a couple of condensers on the 320TL, I’d but this down to problems with the loose connections on the wiring, but the Jumbo seems to have also developed the same habit.

When I’d originally got the Jumbo, one of the main problems was that electrically is was the proverbial dodo. At the time, in order to get a spark I’d swapped the stator plate and loom (probably a generous description for a simple wire and return) from the 1980 320TL. The wiring layout is different on the stators, with three wires on the Jumbo being connected to the condenser, this now being on the 320TL (but they are now swapped round).

SWM 320TL stator plate

The main problem was that Jumbo was now eating condensers, with two failing on the same day. Ok, the condenser is potentially the weak spot on the circuit, so rather than being a problem with the condensor its an indication that all is not well. The purpose (as far as I understand) of the condesor is to store (briefly) a charge and prevents arcing across the contacts, and burning the contact surfaces.

Jumbo stator plate

Ok, so looking at why the electrics were playing up, what are the potential causes ?
– loose connection. I blew a condenser on the 320TL on a Gwent Schoolboys trial and this was (I thought) because the earth lead from the ignition coil had come loose from the mount on the frame after one of the bolts had dropped out.
– problems with condenser(s) failing. The original condensers (that are soldered onto the wiring are much larger that the later condensers, but unlikely that all the condensers I’d had were not good.
– contacts, either the gap is too small or too large, or not properly prepared.
– poor wiring, there is a fault in the wiring, with a short somewhere
– ignition coil failing, could be breaking down as the bike heats up or problems with spark plug.
– bad or poor earth.

So the facts about the ignition system. I’m using NGK B5ES plugs (I’ve not checked the gap), contact breaker gap is 0.40mm and the bike is using the stock, original wiring. So, in a systematic attempt to prevent the world supply of SWM condensers being consumed during 2007, did the following work on the Jumbo:
– condenser: put in a old-style larger condenser (thats all I had in the workshop)
– changed the ignition coil. The one that came with the bike has seen some action (and some silicone sealant)
– checked the continuity, including the earth across the whole wiring loom. I find that doing continuity tests on the contact breaker to be very confusing (it never gives you the reading expect)
– cleaned the contact faces (they weren’t scorched) and reset the gap
– new B5ES plugs (from ebay for £1.20 each)

Also, then did the ignition timing with a strobe and set it to close to TDC (for now) and will adjust later. More reports on the electrical system to come, no doubt.

Another SWM….number 4

A different SWM has been added to the shed, and this time its in a running state…well sort of.

I’d already said to Martin Matthews that I’d like an early red and white SWM, that is from 1978 or 1979. Ok, the engine is the same as the other 280TL’s, but the bike looks much more like one from the 1970’s before everything went a bit plastic in the 80’s.

Then got the email and after offloading 3 Honda’s ( in various states of decay) and a TY175 in a baker’s crate, I reckoned I could balance the books with the domestic accountant (er goddess).

SWM 320TL Guanaco 1978

Went down to view the bike, gave it a quick spin round the drive and the deal was done. The clutch may need some attention soon (rather interesting adjustment , as I took off towards the van ??) but generally in good solid condition. Engine sounded extremely good and the original 1970’s tyres we still serviceable.

Anyway, got it home and put it the shed, ready for the initial look see and ride the garden on the morrow. Ah. Firstly, as indicated during the purchase, the kickstart exploded on the second kick. The circlip holding the kickstart arm to the shaft of the lower knuckle had decided that was enough for now and disintegrated. Martin had mentioned a modification involving tapping a 6mm thread into the shaft on the knuckle, so will look at this at the earliest opportunity.

Then, after getting the kickstart off the other bike, put some petrol in the bike and tried to start it. The cloudy mass moving up the clear plastic fuel pipe didn’t bode well, and she didn’t want to run after 5-10 seconds on choke. Ah well, at least the bike looks good standing still. Some ingestion of petrol later in the week and a good clean of the carb should sort that out.

If it aint broke!

Ok, so someone please explain to me why I saw a bee the other day in London… there I was walking along and it landed on the pavement in front of me… its only the beginning of Febuary… However the plus side is that I can finish spraying the blasted items, including frame, mudguard hanger, coil mount and so on. Here is a picture of the items on their way to the blasters.off_to_the_blaster_sc.jpg
I fixed the swingarm this last week. I bought a welder from a great tool shop, after prcrastinating for some time over prices and power and not finding the MIG I wanted for the price I wanted I decided to check locally. I went to see the chaps at Hunter tools: Here is their site just paste it into your browser and have a quick look: http://www.hunter-tools.co.uk/
Now I dont usually mention businesses and associated services in articles but I thought that these guys were definitely worth a mention. They have a full range of recoil kits and a number of hard to find tools as well as a range of nuts and bolts including nyloc. Very polite and traditional service too. WELL DONE and thanks very much for the new welder, at the time it was the best price I could find on the internet!
Ok adverts aside lets see whats happened, where was I, oh yes so I have bought the MIG after much humming and haaring (well how do you spell it then!) and as the pictures show we have a slight problem with the swingarm…
swing_before_blast_sc.jpg It doesnt look so bad after it has been blasted,
though it did still need welding up if I wanted to make sure that the back wheel didnt overtake me as I was rumbling over some rough terrain! Its been a while since I have done any welding (I used to do mostly MIG) I was tought how to use a MIG welder many years ago by an ex girlfriends father who re-built a Volkswagen beetle by cutting every patch of rust out of the bodywork (which he had suspended from the ceiling in his garage) and welding new metal in its place… talk about patience! anyway he showed me a trick or too when it comes to MIG welding and I will share these with you. Usual disclaimers apply here with emphasis on safety please… ALWAYS wear a suitable welding mask. I prefer a full face with the darkest possible glass as I tend to lean into the work for a closer look! ok I am by no means expert but this will give you enough info to give it a go:
Basic concept: (this may or may not help you troubleshoot a couple of issues with your welding it is certainly NOT a comprehensive guide to the safe use and configuration of a MIG welder)
MIG stands for Metal Inert Gas welding, the concept is that as the metal arcs to the target a molten pool of metal is formed, wire is fed into the molten pool by the welding machine at a pre-determined speed (more about that in a minute) to prevent the molten pool of metal oxidising i.e. reacting with the oxygen in the air an inert gas shield is created around the molten pool, again provided by the welding machine and fed by a replaceable gas bottle. The key to a good weld is smoothly wiggling (technical term) the molten pool of metal into the gap between the two pieces ot metal or along the seam between a join of two pieces of metal. There are a number of things that can ruin this:
A genetic inability to weld (well I told you I wasnt an expert!)
wire speed: too fast and the weld torch will push back in your hand as the wire cant melt quickly enough and is pushing against the work.
Too slow and the wire will have a tendency to melt onto the tip of the torch and stop coming out. (insanely annoying until someone tells you what the problem is)
amps or current: This is essentially the welding power, the thicker the metal the higher the current that is required to achieve a decent penetration (the molten pool of metal is not just the wire as it is fed onto the work it is also the work itself.. hence the strength) The higher the power the more likely it is to burn through the work completely, if your power setting is too low then you will see the weld looking like a line of toothpaste on top of the work rather than a nice D shape.
How do you know its going ok?swing_post_repair_sc.jpg
Well: The work still looks like the swingarm off a Honda TL125 (this may not be the case if you are trying this at home on something other than a swingarm from a Honda TL125. If however it is the case and you did not origimally start with a swingarm off a Honda TL125 then you are deffinitely doing something wrong and should stop immediately and seek assistance)
There are no holes in your clothing from spitting weld and nothing around you is on fire.. sounds silly I know but there is so much heat generated when welding it can cause nasty side effects, be aware of your surroundings… no petrol cans etc. and DEFINITELY NO WELDING OF PETROL TANKS PLEASE just cos its empty certainly does NOT make it safe!!

The sound of a good weld.. sounds strange doesnt it but my wise teacher aptly described it as a sizzling bacon sound, it shouldnt pop or spit but just run nicely across the subject, continuously…. (it was an analogy made all the more appropriate, because as I recall I had a steaming hangover at the time, having taken his daughter out to the pub the night before!)
TOP TIP: make sure that the piece you are welding is ABSOLUTELY CLEAN any rust will cause the welder to spit and it will disturb your nice flowing weld. I prepare the piece with a grinder and or wire brush. Remember also that you can dress your welds afterwards with an angle grinder though do remember that you are actually taking away metal and therefore strength.. so dont go too mad!

Ok so back to the project. I have included a number of photos this week to catch updg_sc.jpg from last weeks rather abrupt article. (I also included a picture of my main helper and trusty sidekick Marbs… always there if you have a biscuit in your hand…

Here are some piccies of the finished frame and sidestand, I have since added the head race and trial fitted the forks(yes end on a high note… ) though I will add these details in the next article. I am rather hoping to get the engine fully cleaned and back into the frame this weekend… I will let you know. frame1_sc.jpgframe3_sc.jpgframe2_sc.jpg

more coming soon… its a lovely weekend and the sun is out … perfect

Gwent STC: Aylburton Common, 04 Feb 2007

First trial for the Jumbo…a good place to try it out and find any gremlins in the bike. The Gwent trial just happened to be the first round on the East South Wales centre championship, though the trial was in England ???

It was -3 C when I left the house, but a sunny morning. Gavin and George followed me down in the van, through the forest to Lydney. Not having been there before, it was surprise to find sections on a wooded hillside with lots of sandstone rocks and that it was very dry.

Looked around for the usual centre twinshock suspects but no-one in sight. There was a tidy Fantic 200 but didn’t see it on the ride round.

First couple sections went clean, with the Jumbo performing ok, pulling like a tractor. There seemed to be some clutch slip on the slopes, mirroring the slip I had felt when carving it around the field at home. Also there is a trick to starting the Jumbo in gear (ie holding the decompressor and the clutch) which I didn’t really manage to master, so need some practice on that.

Aylburton Common

As with all good starts, I hit a rock on Section 7; more of large boulder really and though I got up it, stalled it on the descent. Sections 8 and 9 were fiddly, around some large rocks, whilst double-sub 10-11 was pretty straightforward, with just a tricky turn at the bottom. 12 and 13 were also turns followed by hillclimbs.

A long ride back round to Sections 1-3, all one the side of the hill and though I dropped a couple on Section 2, there weren’t too bad. However had noticed that the clutch was slipping all the time now and making a bit of a rattle so something wasn’t right. With the engine warmed up nicely, it was easy to see how you could set your trousers alight on the mid box.

Section 5

Second lap was still ok, and did better in some sections (and worse elsewhere). Tried doing all the sections in 1st, including the climbs and although the clutch was making this difficult, the Jumbo just pulled like a train with loads of grip. Always seem to loose marks when Graham turns up (and thanks for the photo’s), its the pressure of an audience.

I think is was somewhere on the 3rd lap when I noticed that the rear brake pedal had fallen off and that indeed I had a rear tyre puncture :-). There was also a knocking from the front forks as the load came off them (over a rise etc), but given their current build I half expected that

Section 9, around the rocks

Anyway, though the last 6 sections were a bit of nightmare, with a 5 on section 4 as I stalled the bike on the top of the climb. Finished the trial in about 2.5 hours, with no hanging around and although a cool sunny day, was sweating a lot. The bike had made it, but there were a number of things to sort out, mainly the clutch, which was the whole point of the trial


After checking that the engine runs and most of the mechanical bits do what they should its time to move to the frame and suspension.

Xmas has come and gone and while the relatives were sleeping off their turkey dinners and the enormous quantity of alcohol that my lovely wife provided I found myself itching to head for the shed. I cant say that I wasnt a little disappointed that my presents did not include such xmas essentials as: “a pair of betor shocks”, “a cam sprocket”, “a mig welder”, “a years subscription to trials and motocross weekly”, “a cudly toy”, ” a fondue set”, ” a holiday for two in barbados”……. (yes well it was wearing a little thin at that point so i will stop so you can read on) I will however take this opportunity to publicly thank those responsible for giving me a number of lovely presents and once more getting time to spend with the family…. so its a big thank you to Marbles (the dog) for the lovely socks… I am sure you will have a great time hiding them for me at every opportunity and a big thank you to wifey for the chain lube and Valentino Rossi auto biography.. super.
So as the frantic excitement died down I soon found myself thumping around in the shed much to the amusement of Marbles who has taken to sitting next to me in the rather small shed and watching my every move in the hope that some form of food will magically appear after each task…. he’s still waiting..

Before I could remove the engine for cleaning/serviceing and polishing I thought it would be a good idea to take stock of the nuts and bolts. Focusing on the longevity of the bike and the environment in which I want to run it, I thought it would be wise to replace the often missing nuts and bolts with quality steel items. This job required carefull measurement and analysis of the nuts and bolts taking into account their thread pitch and metric size. As I removed each of the rather worn nuts and bolts from around the engine and various ancilliaries such as the coil mounts and triple clamps I noted the size and thread pitch. I found a great supplier and ordered replacements for each of the nuts and bolts in high tensile steel. This should remove the unsightly gnarled nuts and bolts and complement the soon to be shot blasted frame and engine mount.

The bolts have now arrived and I will post the sizes and thread pitch on the site as it may be usefull to some, though I cannot guarantee that these were the original size and pitch so compare them to the bolts you remove just in case. I am almost down to a naked frame. The engine was very easy to remove and now sits on the workshop bench (well actually.. the small shed! we can all dream) The only trouble was a seized swing arm mounting bolt, it runs through the swing arm bushes and through the center of the pressed steel frame downtube, it had seized in a spectacular fashion and required a lot of soaking with plus gas and gentle pursuasion with a drift in order to extract it… the tired swing arm bushes are now on the new parts list. On removal the swingarm appears to be very badly fractured underneath and is holed as well. This will be addressed with the mig welder when all the items come back from the shot blast shop (and I can lay my hands on a MIG welder). I will post the links to the sites of the suppliers I have used so far at the end of the articles.

I am actually not far from the stage of sending the frame to be blasted and the engine crank case covers as well…. I have gathered some other bits to be sent including front engine mount, coil mount, air box and gear/rear brake levers. pictures to follow of the engine work and frame strip preparation.

I finished taking the last parts off the frame and have taken all the parts to the blasters I decided to take the tank as well… This may or may not turn out well.

Ok I have the parts back… great news.. and they have done a great job. After blasting they have coated the bare metal with a rust inhibitor/anti oxidisation agent, this also has the added benefit of improving paint adhesion… nice! the tanks was a wee bit disappointing as it has a few pin holes in the base.. the jury is still out on what to do about these though the rest of the tank is very solid.. I have a family friend who may be able to work some magic with the tank so I will hand it to him and add an update about it here when I see it again. The main tasks will be to straighten bent parts such as the gear change and brake levers/pushrods and generally prepare for the warmer weather and an opportunity to paint the frame.

So off we go again, well thats what Marbles seems to think he is in the shed peering out as if to say “come on theres work to be done!” I however am standing at the back door looking at the snow! typical…. I was hoping for the warm weather to hold out .. I rekon that I need about 10 degrees to spray… come on Marbs lets go for a walk today instead!

Ok so the snow has gone and I have spent the weekend spraying the frame and some of the anciliaries… I chose black smoothrite.. I have used it before and got great results.. the key here is to apply a number of coats and watch for drips. I applied 6 coats of paint from the 3 cans of smooth black. I have to say its come out better than I hoped and with the front engine mount painted, rear brake lever, airbox, lower triple clamp and sidestand done as well I can step back and take a few snaps of the finished article.

While the paint hardens I am going to focus on the front forks. Stripping them was easy I modified a 6mm long reach allen head socket as I needed a nice strong allen head socket (5mm) would have done the trick however it was not strong enough for the impact wrench. This was used to break the allen head bolt that secures the damper assembly into the fork leg. It is accessed by first draining the fork leg of oil (remove the 10mm drain screw at the back of the fork leg at the base carefull you dont lose the little copper sealing washer in the process) invert the fork leg and then after cleaning out the gunk insert the modified tool and use the impact wrench to undo the allen bolt deep in the fork base. DO NOT remove the fork top yet, the pressure of the compressed spring will hold the allen head bolt securing the damping rod… DO NOT remove the allen head bolt completely though as it could prove very dangerous as the compressed spring unloads, ince you have the allen head screw loose remove the top cap and remove the pressure, then you can remove the allen head bolt in the base of the fork completely. Once that is done the whole fork tube and damper assembly will slide out. The selas are a little trickier as I found. My bike has the original seals fitted and they do not pop out as the fork stanchion is removed as on most modern bikes. They have to be carefully prised out.. even with some heat they would not budge… back to the drawing board. In a flash of inspiration and determined to carry out most tasks on my own I borrowed a friends dremel multi tool, well in actual fact it was a skill multi tool with an extendible head. With the cutting disk attached I used the skil tool to carefully cut the seal and prise the seal away from the aluminium seat. TAKE GREAT CARE… it is all too easy to get carried away and ruin the alluminium seal seat. Once done I was left with a lot of fork parts! next clean and check the fork tubes. Mine are a little pitted higher up but actually are serviceable. So after polishing they are as good as new.. so its back together for the forks….

Time to