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).


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.

Crack in LH side of tank.JPG

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.


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.






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.


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!


Job done (hopefully).

How to pull a bearing out of a blind hole?

With the crankcases split, I decided to replace all of the bearings but one in particular was a problem as it’s fitted into a blind hole, so I couldn’t drift it out from the opposite side like I did on the others.


There may be an easier way but after a bit of head scratching I decided to try to make a threaded puller, that would go into the 15mm bore of the bearing and hook underneath the inner race. I started by turning a nut down to just under 15mm diameter on my friends lathe. I left a small step on one end at 16mm diameter for about 1 mm and then split the nut with a hacksaw, so that it would act like a split collet.


This also gives clearance, so the 2 halves will go into the inner race, with the step engaging under the bearing at the bottom. The plan is to screw a bolt into the split nut and hope it keeps the lip under the inner race whilst the bearing is jacked out.

DSC_0070 TEXT.jpg

I then made a steel spacer with a 36mm counterbore to clear the 35mm diameter of the bearing outer race.


and the finished puller looks like this.


I heated the casting with an electric heat gun to expand the aluminum and reduce the interference fit a little. Then I quickly screwed in the bolt, held the head and screwed the nut down. After a few turns it started to turn easier so something was happening, either the bearing was pulling out or the split nut was pulling through.


and fortunately it was the bearing coming out – job done!


One step forward and none backwards; now that must be a first!








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.


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.

Motogiro D'Italia

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.)

In search of the source of smoking…

There are only 3 ways that oil can get into the combustion chamber:

  • up, past the piston,
  • horizontally, through a break in the head gasket or
  • down, from the valves.

So I’ve removed the cylinder head from the MV to find out which it is.

UP: The piston crown is clean and shows no signs of oil burn at the edges so oil is probably not getting drawn up past the rings. There’s very little movement of the piston in the bore which confirms it’s recently had a new  piston and I can’t see any scoring lines on the bore which would indicate a broken ring.  However,  I will remove the barrel later to be certain.


HORIZONTAL: There is a problem here, as the seal around the oil passage from the barrel to the head is poor, due to the hole in the head gasket being in the wrong place making it eccentric to the O ring.

Part of the O ring is under the gasket and part of it isn’t. This significantly increases the chance of oil leakage and explains why the front of engine was a little wet with oil. However, the seal to the bore doesn’t look like it’s been leaking, so this isn’t the cause of oil getting into the combustion chamber.

DOWN: To remove the valves I had to make a hairpin spring compressor and I then found the inlet valve was wet with oil – not good.

Next I inspected the exhaust valve and port and they were wet with oil – not good, not good at all!

The port is wet with oil around the valve guide and it hasn’t came through the combustion chamber or it would be dry.

THE CAUSE: Is therefore oil getting sucked down both the inlet and exhaust valve guides. Now most people think oil won’t get sucked down the exhaust valve guide due to pressure in the exhaust but this is not the case.  It’s true there are pressure waves but Bernoulli’s principle states that when a fluid increases its speed, the pressure reduces.  This is why carburettors suck fuel up the jet tube into the intake air, it’s also why aeroplanes fly and why you get some suction in areas of exhaust ports. There’s one final sign and that’s the small black patch of burnt oil directly below the inlet valve – see photo.

DSC_0027 TEXT.jpg

This indicates a small amount of oil is dripping through the inlet valve when the engine is stopped then burning when it starts. BUT WHY?

There is some wear on the valve guides but nothing excessive. The problem, I think, is that both valve stems were fitted with an O ring just above the valve guide. Now I guess the previous engine builder expected the none-standard O rings would remain stationary in the alloy spring carrier plate but unfortunately they are going up and down with the valves. Not only does this make them totally useless as an oil seal, it actually makes them act like a reciprocating pump – one that pumps oil down the valve guide! When the valve is up, the recess below the O ring fills with oil and when the valve goes down the O ring compresses the oil and pushes it down the guide – not good.



THE SOLUTION: I could just remove the O rings and hope that this solves the problem. But it would be better if I could improve the valve stem sealing, as insurance and that’s what I’m going to do.  So it’s off the my local engine repair machine shop, where the owner “lends” me a large sweet jar filled with surplus valve stem seals with the instruction, “see if you can get any of those to fit” – happy days!

And it looks like one of these 2 types should fit, with a little trimming.


and then the finished job will look like this.


All I need to do is trim the underside of the valve stem seal, so it will seal effectively against the top of the valve guide. There’s a nice recess on the underside of the alloy spring holder that will hold the seal in place and prevent it from moving up and down, like the O rings – hopefully….


I’ve now removed the barrel and everything looks good. Virtually no wear and the piston and rings are near new. The piston is the 4 ring type (2 x oil control rings and 2 x compression rings) so the likelihood of oil being sucked up is very remote.


The piston ring gaps, measured 25mm down from the top of the barrel are:

  • Top compression ring = 0.65mm = 0.025″
  • Lower compression ring = 0.52mm = 0.020″
  • Top oil control ring = 1.21mm = 0.047″
  • Lower oil control ring = 0.42mm = 0.016″

The top 3 are a little bigger than I would like. However, current thinking is that ring gap is not as critical as previously thought and many modern engines run quite big gaps from new.

But to be safe, I will drop the piston manufacturer,  “Asso” an email to get their opinion.

So, it’s new gaskets and back together. I just need to decide whether to make a copper head gasket or buy a composite one, as some say copper is much more reliable.

a day of discovery…

as the MV is now road legal. So I’ve been out riding to find out what is good… and not so good.

First the good. It’s amazingly fast, extremely comfortable with fantastic brakes. At least compared to my Cyclemaster! It also generates quite a bit of interest  – probably because it’s red and Italian, a bit like a Ferrari to the 4 wheel petrolheads.


But there are some less good aspects. First, it’s smoking a little but I’m hoping that’s because the motor is running in, after the new piston was fitted (eternal optimist at large). And the fueling is very poor. It won’t idle and seems to be running rich. It hesitates at full throttle and then picks up as the throttle is rolled back.

So it’s another carb strip to check the idle jet and pilot circuit. Everything looks fine apart from the pilot jet is very small at No.35. Such a small pilot jet is most often used on smaller engines around 125cc and research saws the early version of this engine was fitted with a No.45 jet. As luck would have it, the spare carb bought with the MV has a No.40 jet, so it’s worth a try. Good news, it now idles OK but still won’t rev out correctly, regardless of slide needle position.

A quick bit of research on the excellent Dellorto website uncovered the original carburettor settings and for some strange reason both the main jet and throttle needle are the wrong parts. The main jet should be 102 and a 109 is fitted; the needle should be E12 and an E10 is fitted. The E10 needle is much smaller at the pointed end and this is the cause of the rich mixture at large throttle openings – problem solved.

But not quite.

The engine now pulls and revs much better but the extra torque is making the clutch slip….

and the battery is not charging……

and the petrol taps drip…….

and the speedo reads wrong…….

and the sump plate is leaking a little oil……

and the cam box cover is leaking a little……

and finally (for now) there’s the cam shaft oil feed mod I want to do. The standard method is to drip oil onto the camshaft from a tube mounted above it but this isn’t very effective as the spinning cam shaft just throws the oil away, leading to premature camshaft wear and failure.


The better method is to feed the oil through the camshaft (like all modern OHC engines) and this is the mod I want to do – WHEN I FIGURE OUT HOW.





the search is over and quicker than I thought…

It was probably an omen, when the Facebook post from my last blog selected the MV Agusta as the banner photo. Because that’s what I’ve bought. Not a black and red MV Agusta CSTL (as shown in the last post) but a red 175 Sport Monoalbero “CS57” (as shown below when it arrived home).


There was only 500 of this model made, so it’s a fairly rare piece of equipment.

Vintage Motorcycle Photographs

However, it’s the last model in a family of MV’s that include the famous 175 CSS, or “Disco Volante” as it became known. This name translates to “Flying Saucer” and was given to the 1954 CSS due to the shape of the petrol tank. Very unusual, very attractive, and one of the most desirable motorcycles ever produced.

My bike shares many parts with the “Disco” and is often called the “Discette” – same engine with lower power and same cycle parts with the exception of the front forks and that tank. Key design features are:

  • Large fin alloy cylinder head.
  • Double hairpin valve springs (reduced moving mass so engine can rev higher – 8k)
  • Single overhead camshaft, chain driven (with adjustable cam timing in the case of the CSS)
  • Alloy rims with full width front brake (aids heat dissipation)
  • Composite tubular and pressed steel frame, with engine as a structural element
  • Sporting set-up with low bars and narrow seat
  • Large 22mm Dellorto carburetor with inlet trumpet – 25mm on CSS.

These features made the MV Agusta CS series the small sports bike to have in the ’50.


Racers bought them to compete in the up to 200cc class and Mike Hailwood won his first race on one, at Oulton Park in 1957. The factory race version, right, was given the name “Squalo” which means “Shark” due to the shape of the nose cone – stunning!

MV Agusta were undisputed world leaders in this era, so my CS has a lot to live up to.

The official line is that it needs “light recommissioning” which could be changing the oil to a full re-build; only time will tell. Fortunately, the seller got a bit obsessed with buying spares, (his admission) so the bike comes with a comprehensive set, even including a full engine. For now, I can ony drool over the beautiful design features below.


My broad plan is to simply “bed-in” all of the work that has been done to the MV over the last 15 years, as it hasn’t been used much in that time. For example it’s been running-in since 2004 when a new barrel liner and high-compression piston were fitted. The first action will be to sort the fuelling as it refused to run at low revs, most likely due to a blocked primary jet from rust in the petrol tank. When I’ve done this, I’ll use “Harvey” a little and decide what needs doing over the winter, in preparation for next years adventures.

Let the fun begin..




This dream came from reading a Classic Bike mag …..

Classic bikethe June 2015 issue to be exact that featured an article on the Motogiro d’Italia.

I’d never heard of it before but riding 1500km around Italy, on 50’s bikes, appeals to me. And of  course there’s pasta as well …..

It’s what’s called a “regularity” which means it’s not a race, as racing on public roads in Italy is banned. What you have to do is start at a given time and place, then arrive at a given destination after covering the distance between the two points at a given average speed. And of course the given average speed is always within the legal speed limits, unless you get delayed of course. And then you have to catch up or get penalties for late arrival, so you ride like a bat out of hell – so to speak.

The Motogiro had its hayday in the 50’s, when the Italian manufacturers used it to prove and then sell, their machines. Motorcycles up to 175cc were very popular and it’s fair to say that the Italian manufacturers were world leaders in small capacity machines at this time. In those days the Motogiro was a high-speed race over a long distance, with special works bikes, ridden by factory racers. It was banned by the Italian government in 1957 in the aftermath of a terrible accident in the Mille Miglia. However, it was successfully relaunched in 1989 as a road time trial and has gone from strength to strength since then.


There’s also the “Milano Taranto”, an event that covers 1400km over 6 days, from Milan in the north to Taranto on the Mediterannean coast – just on the instep of the boot. Currently, I like the feel of this event better as it’s a linear event with the start and finish at opposite ends of Italy, whereas the Motogiro comprises a series loops mainly in Northern Italy. (hence the word giro, meaning gyration).

However, I have a lot more research to do, if this dream is to ever become reality.

There are several categories in both events, including modern machines but the essence of the event for me, is the Historics – machines of the type that were used in the 50’s.

So, what I need is a Gilera?


or a Moto Morini?


or a Ducati? (but I’ve never really liked them)


or an MV Agusta,


or a ParilaParilla 175_51

or even a Guzzi.


What would you buy?

Let the search begin….