4 days to go and I’m ready but it hasn’t been easy.

Speaking as a reformed pessimist, I’ve made good progress. The engine is running well following the re-build. There are no unusual noises, it doesn’t drip oil over the floor and more importantly, the blue cloud of exhaust smoke that followed me (and sometimes passed me) has gone.  So the exhaust valve seals are doing their job and I can be confident the engine internals are as good as I can get them.

But I had doubts about the oil pressure relief valve and in particular the pressure relief spring that had been over stretched. Few things will kill a good engine as quick as low oil pressure and nothing makes the engine leak oil like too much pressure. So after too much calculating and measuring, I fitted a new spring, attached a pressure gauge and was delighted to find 60 psi at the camshaft – perfect (I think).

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And then, after a short ride I noticed the smell of petrol. It could have been a leaking gasket but no; the petrol tank had split on the underside.

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And then I realised I was legging it when pulling away uphill, like a 3 year old on a scooter, who’s just heard the ice cream van has pulled into the street. (those of my age will understand). No option but to reduce the teeth on the engine sprocket and no option other than to make one – old 18T sprocket for the hub and new 17T for the teeth – a cut and weld job that turned out well.

Race plates fitted and ready for action.

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It even runs quite well and rides even better.

Now it’s off to Bologna for the start of Motogiro D’Italia 2018 and with luck, I may even make the end; riding that is and not in the back of the support van.

I’ll post my progress over the coming days – stay tuned.

 

 

 

 

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I really do need my head looking at..

my cylinder head that is.

After making a second copper head gasket to get the correct cam chain tension and fitting the head, I found I could see light through the joint! Worse still, it was at the edge near where the oil gallery runs. So back off with the head and this is what I found.

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Ideally the head and barrel should be skimmed on a horizontal milling machine to correct the “out of flat” but I don’t have one. So it’s back to my friends trusty old Colchester lathe to see if I can skim the head and barrel on that.

First problem was how to hold the head and I settled on making a frame from aluminium extrusion that I secured to the head using the 4 x M6 cam cover holes. I then clamped the aluminium frame in a 4 jaw chuck and trued up the head face using a dial indicator.

Using a new TCT tip tool, I skimmed the head, using a very slow cross slide auto feed, to get the smoothest finish possible and in total I removed 0.19mm.

To skim the barrel, I first made a plug out of nylon, that was a tight slide fit into the bore – tight enough that it needed tapping in place with a mallet but hopefully not so tight that it would split the steel liner.  The plug served 2 purposes. Firstly to allow the liner skirt to be clamped in a 3 jaw chuck without risk of crushing the skirt and secondly to keep the barrel true by supporting it with a floating tailstock.

To true the face, I removed 0.14mm. The good news was that removing a total of 0.33mm, enabled me to use the fist copper gasket I made; the 1,2mm thick one.

Now the joint is perfect and clamps up without daylight!

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Job done (hopefully).

115 days to go to the Motogiro D’Italia…

and it’s turned into a full engine rebuild.

I’d hoped to get away with minor bedding-in but the list of issues has grown to the point where I can’t trust anything,

  1. Burning oil due to to non standard O rings being fitted in the wrong place on the valves
  2. Cylinder head gasket leaking oil due to poor head gasket alignment
  3. Overhead Camshaft bearings not running smooth
  4. Cam chain far too tight as cylinder gaskets were too thick (hence cam bearing problem)
  5. Slipping clutch with springs shimmed up and going coil bound
  6. Excess end float on clutch basket causing clutch to rub on Primary cover at one side and clash a little with the drive gear when it thrusts the other other way. (helical gears)
  7. Gearbox input shaft doesn’t turn as smooth as it should, so there could be a bearing issue in the gearbox.

So that made my mind up for me. Full strip and check everything.

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And it’s just as well I did. The previous engine builder had a preference for using silicone for gaskets and like most people, used far too much. It then squeezes into the engine and can break away blocking oilways, leading to total engine failure. Not something I want to happen in the middle of Italy…

 

 

no going back …

as I’ve now booked my place on,

The 26th edition of the Motogiro d’Italia

that’s 154 days to get the MV sorted, ready and in Bologna for Monday 30th April 2018 for scrutineering. Stage 1 starts the following day with the sixth and final stage on Sunday 6th May, after which I’ll hopefully have covered 1576 km or 979 miles.

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There’s museums and other events along the route and we finish at the Ducati factory, who are sponsoring the event this year.

Next April sounds a long way off but the MV is in pieces and will be until January when the new clutch arrives. I’ll then have to hope the weather is kind, so I can fit in some long “settling-in” rides, complete with thermals.

and there’s the transport and logistics to organise

and a spares package to pull together

and I need to find out what this means:

“a TIME TRIAL event (MOTORAID) founded on: transfers, time check controls, time and stamp check controls and ability trials, that will take place in the localities described in the check cards. for the competition”

and the MV needs fitting with 3 event number plates

and it’s not charging and the speedo doesn’t work

and learning some basic Italian wouldn’t be a bad idea..

As I said there’s, “not going back” because the deposit is non-refundable. So if all else fails, I’ll be the first and probably the last, to attempt the Motogiro on a Cyclemaster.

(979 miles at 15mph average = 11 hours riding per day. That’s doable isn’t it? I may even get an award for the slowest ever finisher.)

we have lift off – thanks to Bernoulli…

and a few other things as well.

First, there’s the engine de-coke and re-build. Whilst doing this, I opened the exhaust port a little and opened the exhaust port throat a little more, smoothing the flow as best I could. A new crankshaft seal was fitted on the drive side and I took particular care to seal the small gap above the key way slot, in the primary drive sprocket, as some primary compression can be lost here. The little end bush also seemed a little tight, so the bush was gently eased using 1500 grade wet and dry sandpaper.

Second, I’ve flexibly mounted the carburetor. Now I was quite nervous about cutting the inlet manifold as there’s no going back but I did it anyway and fortunately, it worked out quite well.

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The advantages I hope to gain are:

  1. Reduced vibration of the carb that could be causing the float to bounce and flood with petrol; a persistent problem I’ve had,
  2. Reduced heat transfer to the carb from the engine, that I suspect is causing vapour locking , NB: Petrol boils at 95C, however ethanol boils at 78C, so modern fuel are far more prone to this. Sir Walter has always been a bad starter, 10 and 20 minutes after a hot stop.
  3. Increased clearance between the carb and the wheel as the petrol connector nut can touch the wheel, particularly if the wheel bearings are set a little loose. I cut 6mm out of the manifold and left a 3mm gap between the ends.

The finished job looks quite neat, as shown. You’ll see I changed to a different rubber hose as the black one above was too tight. I just hope the clear reinforced hose I used is ethanol proof, or I’ve a breakdown waiting to happen.  I’ve also added some thick black foam rubber around the inlet spigot, so that it’s supported where it goes through the carburetor cover.

Third, I’ve lapped the float needle to the petrol connector using a new method. Previously I’ve spun the needle in a drill whilst holding the petrol connector between my thumb and finger. The problem with this method is the lapped seat may not be axially aligned as it’s done outside the carburetor body. Consequently, it may leak when assembled.

First step is to make a nylon plug on a lathe, that’s a tight slide fit into the float bowl. Also drill a 1.6mm hole in the centre of the plug (on the lathe) to take the float needle, thereby ensuring the 2 diameters are perfectly concentric.

Then fit the petrol connector into the base of the float chamber with its fibre washer and tighten. Next put a dab of fine abrasive paste (Solvol Autosol) on the needle seat and insert it into connector and up through the nylon plug. Finally carefully tighten the chuck of a battery drill onto the exposed tip of the needle and spin it slowly for a minute or so.

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Repeat this, cleaning the needle each time, until a good even seat can be seen on the needle. The beauty of this method is that the new seat is perfectly aligned and shouldn’t (I hope) leak.

 

Fourth, open up the silencer to improve gas flow. This also makes it louder and it’s a scientific fact that something loud goes faster; or so it seems. My silencer is the type that doesn’t come apart (for cleaning), so I simply drilled a 10mm hole in the baffle plate that I could see inside the tailpipe. Yes, crude but effective.

 

So what’s this got to do with Bernoulli? Well in 1738 Daniel Bernoulli published a book called “Hydrodynamica” (great title), in which he detailed some principles of fluid dynamics.

In a nut shell, he stated that, “if a fluid (liquid or gas) increases its speed, then the pressure drops” and this is one of the fundamental reasons that a 2 stroke engine works. As the products of combustion accelerate down the exhaust port, they cause a drop in pressure that sucks the fresh fuel charge into the cylinder. So it follows that the faster the gases exhaust, the lower the pressure, the greater the suck, the more fuel is drawn in and the more power you get – simple. And that’s what I’ve done to improve Sir Walter, (amongst other things) and IT WORKS!

He can now climb steeper hills without LPA, he’s revving out much, much better and he even sounds fast.

PS, Bernoulli’s principle is why aeroplane wings generate lift, a spinning football bends, ships can’t pass close at sea, jetties always have water beneath them and why a F1 car’s areopackage works, amongst many other things.  Where would we be without Hydrodynamica?

 

all is not well…

as Sir Walter has lost what little “get up and go” he had. Now he’s more “slow down and stop”. I always had to use LPA (light pedal assistance) on hills but now I’m doing it on the flat!  He also hasn’t revved out correctly for weeks, even when stationary with the clutch in.

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I’ve tried everything without success, so it’s time for a strip down to see what’s going on.

And the cause became evident very quickly. The Cyclemaster engine is already limited by the exhaust port area, so carbon build-up like this just stops it breathing. If the burnt gases can’t get out then the fresh charge doesn’t get sucked in.

Oddly, the transfer ports were also partially blocked up.

                           EXHAUST PORT                                    TRANSFER PORT

Restrictions like this have a very severe effect on a 2 stroke (negative unfortunately)  as they disrupt scavenging; the effect where the outgoing exhaust gasses suck in the fresh charge. Cyclemaster utilises Schnuerle porting, like the majority of 2 strokes.

Schnuerle porting loop scavenging

The cylinder has a single exhaust port and two transfer ports that are angled backwards. This causes the fresh charge to swirl away from the exhaust port and up towards the spark plug, minimising mixing of the burnt and fresh gases and improving efficiency. You’ll see the exhaust port opens before the transfer ports, when the piston is travelling down, causing the high pressure gases to vent through the exhaust. This flow of hot, expanding gases generates suction behind the flow, that helps draw in the fresh charge – at least when the ports aren’t blocked with carbon. And why have they blocked so quickly in less than 1000 miles?

I’ve added oil to the petrol in the correct ratio of 25:1 (or 4%). The recommended oil in 1952 was SAE30, so I’ve used Coma 2T that’s based on 30 grade mineral oil. It’s Jasco FB rated on ash content, so I expected it to be OK but it’s obviously not. Being positive, the engine hasn’t seized, which is a common problem with the Cyclemaster as they run very hot due to marginal cooling.

So what next?

When re-assembled, I’ll start with semi synthetic (Jasco FD) at 30:1 for a tank or 2, whilst the rings bed in. I’ll then change to fully synthetic at 35:1 and maybe even 40:1 over the cooler months.

And hopefully, Sir Walter will be back to climbing hills again.

I don’t know where this started but I do know where it’s going….

and hopefully, that’s from the East Coast of England to the West Coast, when Sir Walter and I partake in the East to West Adventure.

Or to be exact, from Crimdon Dean (famous North East Holiday resort) to Whitehaven (famous Cumbrian Georgian seaside town), covering a distance of 135 miles and crossing the Pennines with a total climb of 6,666 feet.

However, the build up didn’t go well. Ten days before the event I noticed a broken rear spoke. Oh well, perhaps one broken spoke would be OK? Then Sir Walter started to run weak, wasn’t revving out very well and had less pulling power than the elephant man in a nightclub. And then, when testing different engine setting, I hit a pothole and broke another spoke. So it was engine out, strip down and re-build with just a few days to go. This revealed a broken carburettor casting where it clamps to the inlet spigot (common problem) and I figured it was sliding back off the spigot and leaking air; hence the weak mixture. At this point I must give credit to Pete Stratford and Philip Crowder, who sent me the parts required, at short notice and enabled me to get Sir Walter back together the day before the event – thankyou.

Things were looking good on Day 1 at Crimdon Dean when Sir Walter started first spin, which is quite unusual but it impressed the watching crowd (4 people including my son Christopher). However, It quickly went downhill as the engine was revving even worse and Sir Walter seemed to want to be a plodding 4 stroke rather than a buzzing 2 stroke. Dropping the needle 1 notch helped but anything above half throttle resulted in Sir Walter going even slower. Not good, as a strong 18 mph headwind was forecast for Upper Teesdale. My enthusiasm was further dented when a fellow rider (who shall remain nameless but you know who you are) said I wouldn’t make it to Alston before dark!

 

However, things settled down and Sir Walter was reasonably happy at 5/8 throttle – I know because I’ve added graduated marks to the lever! Soon, I was caught “speeding” through Trimdon but please note, I only pedalled like that for fun and my son certainly found it funny based on the chuckling.

So onwards to Shildon where I tried advancing the timing but it was no better. And then on to Staindrop for lunch, where I tried retarding the timing but still no better. Then on to Egglestone where I tried reducing the points gap but, you guessed, still no better. Time to give up on adjustments and slog up Teesdale. And I did, through some of the best scenery the UK has to offer. Sir Walter was flat out (5/8 throttle) for one and half hours, with “gentle” LPA (light pedal assistance) and it was a delight to spend the time absorbing the wonderful views. This area really is one of the best kept secrets in the UK.

The only downside was the wind. Around Yad Moss, it was getting difficult to make forward progress and I was a little worried I’d get blown off the road and have to spend the night on the moor. However, I knew that support from Martin Wikner was only a phone call away… but I had no signal. And then Alston appeared and it was still light, even at 4:30. Oh yee of little faith, Sir Walter had delivered with a little help from me.

After a quick look around the Hub museum, which is well worth a visit, I then went back down the hill (not the best of planning) to Garrigill to find my B&B and a well earned rest.

The next day started bright and sunny, as Sir Walter posed for an early morning shot.

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Eastview Bed and Breakfast, Garrigill

Now, being the entrant with the smallest engine and slowest vehicle, I decided to get an early start the next day, and head for Hartside an hour earlier than planned. Some would call it cheating but I was getting embarrassing arriving everywhere last. As it turned out I was the third entrant to arrive at Hartside, looking a little like Laurel or is it Hardy. You just can’t get good passer-by photographers these days, or perhaps it’s the subject? Or was I just happy to have made it?

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It was now onwards and downwards, or so I hoped, to Hesket Newmarket in the Northern Lakes. This leg went well despite some surprisingly steep (up) hills that we just managed to climb under power – no walking for me and Walter.

And then dismay, in front of a large crowd at Hesket Newmarket, he wouldn’t start. So I pedal up the street with the choke on. Then pedal back down with the choke off and still no firing. Pause for thought, twiddle a bit (technical term), try again and heh presto away he goes. But it gets better. After a short distance, Sir Walter really starts to rev well and buzz like he should. Until that is, he splutters and stops. Good news is, I’d switched the petrol off during the twiddling phase. Even better news is, it proves the revving problem is flooding of the carburettor. Only dissapointment is that it’s taken me almost 100 miles to realise this and I only did it by accident; so much for being an “Engineer”. But now is not the time for a carb strip, so it’s onwards and upwards to Bassenthwaite where my wife and son are waiting to meet me at the Lakes Distillery.

The final leg is a leisurely run through lovely english countryside into Whitehaven via Cockermouth, where I arrive last as usual but extremely pleased to have completed the Adventure.

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Made it, and aren’t I pleased! So pleased, I even did a burn-out, Cyclemaster style.

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And we finished, albeit last to every checkpoint, including the finish. But as Philip Crowder said, anybody can do the East to West on a moped but I was the only one on a cyclemotor.

So the journey is over. Not just the journey to Whitehaven but the journey back to life for a rusty Cyclemotor that hadn’t ran for 50 years. And there is something special about a Cyclemaster; it’s to do with the way you have to work together, particularly when faced with a hill – you help the engine and it helps you.

Man and machine in perfect harmony, now looking for the next challenge.

Acknowledgments

I must thanks, those who helped me from the EACC. In particular Martin Wikner who drove support and Sharon who both planned the route (with help from Dave Watson) and rode it on her little red Honda. And thanks to Neil Catling for his words of encouragement.

And finally, thanks to my sons for their help: Christopher for getting me to the start, Daniel for getting me home from Whitehaven and Michael for looking after Mam and driving her to the Lakes Distillery to laugh at me.