In the workshop
With the country in lockdown due to pandemic regulations, and auto jumbles cancelled, there’s been little option but to use what was already in the workshop.
Well, a lot's been happening in the workshop these past few weeks. Some of it good, some of it frustrating and some of it actually producing progress.
It seems as though every feature I’ve written for any magazine recently – be they motorcycle or woodwork orientated – has kicked off with a similar theme… this pandemic and its effects on life as we know it. Sadly, this magazine is no exception, but astss signs of a return to some form of normality.
With a few projects on the go and an inability to scour the show and autojumble scene for bits and p eces to keep some momentum up on the official tasks, the e’s been a chance to look at some other bikes in the workshop.
My BSA B40 for instance has been growing more incontinent with every passing dy and the cables which Venhill made for me durin the course of af ea tue a few years ago are way past their best.
Coming forward a little, my lad’s Fantic 201 is looking a bit sorry for itself as the rear mudguard is at an odd angle and the silencer had been too close to the rear tyre. As a temporary fix I’d packed the silencer out so it would clear the tyre, but this threw the side of the mudguard all to pot and the air of accusa on with the little voice calling ‘fix me properly’ becoming louder. Then there is the Montesa Cota 200 which belongs to my uncle and is a much abused trials bike in need of TLC, or at least my version of it. Biggest problems with this bike are centred around it going ‘clunk’ before stopping and the neat tank/seat unit delaminating thanks to the effects of modern petrol. There was a tricky moment with this bike when a kick-start lever, sourced by a friend, vanished in the post which meant convincing the owner to buy a new one… Then there was the attempt to get some signs of life into not only the Montesa but my Triumph and the CDB Yamaha…
Well oiled
First though the steady flow of oil from just about everywhere on the engine in my B40 was becoming more unacceptable and as there is a possibility the bike will be up for sale shortly it was deemed sensible to stop the leaks.
I’ve had several goes at trying this in the past but not to any great extent, generally because instead of spending time to do the job it’s been a quick squirt of gasket goo or sealer then on to something else. I’d convinced myself the whole engine would have to come apart and was prepared to do just that which is one reason why I’d been putting it off, I didn’t want too many bikes in bits in the workshop.
This time though I put the bike up on my workbench, cleaned the underside off and spent a couple of days seeing just where the oil was coming from before I ripped into the job.
With the underside clean I laid out some paper towel underneath and left it overnight. Next day the oil trace was a little clearer. In case you’re not familiar with a B40 Beezer engine there is a pressed steel sump plate at the very bottom of it, normally this mounts on four studs with nuts and a series of gaskets between the plate and the engine. This clamps up and hopefully seals everything which is adequate for a road engine but the studs protrude a little too far for a comp bike with a bash plate on, so four Allen screws replace them. I did wonder if the oil issue could be because this plate had been dinged, even through the bash plate, and possibly split, but it turned out not to be the case.
There was some oil leaking past one of the Allen screws and forming a drip but there was also some oil weeping from the side case… was it enough to form the drip on the Allen screw I wondered? ‘Possibly’ was the best I could come up with so a twist of paper towel pushed between the engine and the frame to prevent the oil trickling down and on to the Allen screw stopped that, more paper towel under the bike and the underside cleaned off I left it again for a few hours.
There was still a drip of oil from the sump plate area so rather than attempt the fix while bending over the side of the bike I hoicked the engine out, popped it in my engine cradle and started to pull things apart.
Again working slowly and trying to see where the problem actually was rather than assuming where it was, meant the strip down took longer than it would have normally. Instead of piling all the bits up then washing them I cleaned each piece as I went… again a longer process, but… From this slow work I found the side case hadn’t been sealing properly, nor was it actually touching all faces. Flattening the case off on a mirror with wet and dry paper taped to it improved matters no end and once it was clean a light smear of grease showed both faces now actually touched where they should.
The sump plate was more involved to seal however, and needed squaring up as the faces were out of shape. Once the plate was stripped and all the crap cleaned off holding it in place, it revealed how badly out of shape it was. This I cured by clamping it in a vice so the plate could be bent back and forth until it was right. While dealing with this area I also looked very closely at the plate – with a magnifying glass actually – and made sure it wasn’t split.
Before putting the plate back on, a bit of advice arrived from 1966 SSDT winner Alan Lampkin: “check the length of the screws…” I did, they were almost the right length. To test things even more I screwed the fasteners in place with the sump plate where it sits but didn’t put any gaskets or washers on. The plate was almost tight enough but had a little play, the screws were a thread or two too long so they were shortened by a thread or two, then I fitted them properly, didn’t put any gaskets or gasket goo on the plate and filled the sump with oil and left it overnight.
Next morning the paper under the engine showed not a speck of oil at all. Encouraged, the plate came off, was cleaned and gaskets with Loctite 518 applied went on. Once tightened, I did the sump test again and the paper towel stayed oil-free. It was a reasonably quick job to assemble the rest of the engine and slot it back in the frame. Then came the big test… firing the bike up and riding it then letting it cool to see if it stayed oil-tight. It did. Less impressive was the condition of the cables. So, the cable making kit was hauled out and some new cables sorted.
Out of line
It is a fact that a competition bike has a hard life and will occasionally get dinged in action. Some bikes cope with this better than others of course and then there are the comments from those more familiar with a particular model than you… you know what I mean, you ask a question and back comes “they all do that..” or “Yes, that happens on all of them when they’re dropped…”
With this 201 Fantic the silencer had been rubbing on the tyre so as a quick fix I’d pushed the silencer out with some spacers. It was only a temporary measure, nearly said ‘fix’ but it wasn’t a fix, and the time had come to do something about it.
Speaking to those who know more about this model than me it seems the rear subframe doesn’t react well to being dropped on its side and bends in slightly, not a lot, but enough to move things even closer to the tyre. Once the world went monoshock the rear of the frame had no other job to do but support the mudguard and maybe a seat. On the Fantic and other bikes too there’s not a lot of strength in this area now and it is supported by a curved steel bar about 8mm in diameter. The answer is to cut the loop off at one end, ease the tube of the frame out, rebend the round bar and weld it back on, but the sub frame has to come off to do this.
Thanks to it playing pretty much a supporting role in the frame game, stripping it off isn’t too difficult but I’ve not done it before so worked slowly. Getting the mudguard, silencer and airbox off was achieved quickly, as was cutting the bar and easing out the
1: No way is this air filter ever going to filter air… a new one is now in place.
2: Obviously this isn’t in line and has been dropped – not by me – on the silencer side.
3: You can just see the distance pieces fitted as a temporary measure to move the silencer over.
4: Stripping the stuff off and removing the curved brace from the sub-frame meant I could move the tube over a bit. frame tube with an old bit of scaffold pole. Apart from a bolt or two seizing in place the subframe came off quite easily and was welded in a few moments… though not by me as I’m not a welder but luckily I know people who are. Once welded and a lick of paint added, back on it went, the guard sat in place nicely and assembly went reasonably quickly after that. Right up until the decision to clean the air filter… oh dear, it may have been an air filter at one time but now it was a fragile crumbling piece of foam. I think the last possible breath of air had gone through the filter and the next stage was the filter being sucked into the carburettor which wouldn’t do it any good at all.
Bill Pye at Frankfield Fantic had some new air filters in stock and one was soon winging its way to CDB’S Northern HQ to be fitted in place and all was now well in the Fantic breathing department – the mudguard sits where it should and I can claim to be a responsible parent taking care of the off-spring’s bike.
“Oh dear, it may have been an air filter at one time but now it was a fragile crumbling piece of foam.”
Under pressure
To be asked to fettle up a bike which has been neglected quite a bit in its life is a daunting thing and not something I would do for a living, in fact had the bike not belonged to a relative I’d not have looked at it. The bike had stopped with a clunk recently and such noises never bode well.
Stripping a two-stroke isn’t difficult, at least down to the crank mouth anyway. There are a number of things which should be changed on a two-stroke on a regular basis. Cranks seals are one such item and on enquiring when they were last changed it seems they haven’t ever been while in current ownership.
So, at the last show pre-lockdown a pair of engine seals for a Montesa Cota MH200 were bought ready for the strip, but first I wanted to know why the engine had gone clunk. With the tank unit out of the way and ignored for the moment, the exhaust system was removed, airbox and carb too. The head on these Cotas are held on by four nuts, undoing them the head lifted off and the combustion chamber was found to be a bit choked with carbon, so that was cleaned off. The top of the piston too was needing decoke but I wanted to get the barrel off before I did that.
There are four 7mm Allen screws which hold the barrel on, these are a tube type and need a special Montesa tool to reach in… which I have, after a friend gave me his in the Seventies. These tubes mount on thick steel washers… or at least three of them did. Off came the barrel and the reason for the clunk became obvious… a huge chunk was missing from the piston and the barrel scored. We managed to find a newer barrel and piston to replace the damaged items as pistons are quite scarce for this model, but at least we didn’t need to decoke the piston.
Now in order to change the crank seals both sides of the engine have to be stripped out to access them, unlike my Bulto, the Montesa seals are pressed straight in the case rather than on removable plates, it’s not easy to get seals out from such an arrangement but I did and the new ones went in place. This all sounds like it was a simple job to strip out the engine… I suppose it was once I realised the nuts on either side of the crank – ignition and primary – were left-hand thread… In order to reassemble the engine though, a holder was needed to lock the crank weight in place while the nut was tightened.
I don’t know what tool Montesa used or supplied for this task, but my attempt was a thick steel bar with a big hole in to go over the crank weight cog and three holes for the corresponding tapped holes in the crank weight.
Once the bits and pieces arrive through the post then assembly will begin. While waiting, a temporary fuel tank was cobbled together as ethanol petrol had eaten its way through the glass fibre of the original. To repair such a tank is possible but the feeling is the bike needs to run first to see what it’s like, so a cobbled up arrangement it is. Of course, the tank I had spare is only just wide enough to sit in place but the coil needs to be tucked further in…
A spark of an idea
A petrol engine needs some form of electrical spark to make the brmmm noise which excites us so much. There are a number of ways to achieve this happy state depending on the age of the motorcycle.
Older bikes will have a magneto, moving forward a bit are flywheel magnetos, then electronic systems came in and all work brilliantly until they don’t. On my project Triumph, the spark is provided by an electrical current generated by an alternator which sends either 6 or 12v up some wires to a coil and then on to a distributor… from this description you will gather I don’t fully understand this elctrickery thing but what I do understand is there’s no way the distributor on this bike would ever produce a spark.
Let’s for the moment ignore the obvious fact the distributor is so choked up with years of muck, grease and other rubbish it is less puzzling it doesn’t spark and more amazing it actually spins! No even if it did spin the missing carbon fibre brush in the distributor cap would mean no spark at all. A quick call to the Distributor Doctor and a quote of the model number on the unit brought a lot of helpful information and also had a carbon fibre brush heading my way. While waiting for it I pulled the distributor apart, working slowly and taking pics on my phone as a modern equivalent of a notepad, the muck was removed and the thing reassembled and lubed, the new brush fitted in place and now all I need is to do is persuade the alternator to send a charge up those pesky wires to it…
Meanwhile in the modern corner of the workshop stands an IT465 which also is devoid of a spark… this is less problematical as the whole system was refurbished by West Country Windings a while ago and has been waiting for me to pluck up courage to reattach everything to the bike.
Buoyed up by the successes of the distributor build I read the Yamaha manual, laid out all the bits and started adding them to the bike… On stripping it some years ago I put a centre punch mark on the stator plate and the crankcase so I will at least be able to put it back to where it was… less sure if this position was right in the first place…
Still, after an hour or so’s work, a couple of dead ends and back-tracks there was a little blue spark at the end of the spark plug. Tipping oil in the engine produced a pool of oil under the engine… and the realisation I had only put the primary case on finger tight… At that point things start to accumulate and the only option is use the work shop kettle and make a coffee and do something else for a few moments.