How far to go?

[G3L1946]

Good morning to you all,
The bike is now devoid of all that can be removed and is now a running chassis. The engine sits on the bench in my recently construct jig ( bit of an over-kill job, it would probably support a Rolls Royce Merlin engine!).
As I survey it I ask myself ‘ where to start' but, just as importantly for me, how far do I go in stripping it down? Do I go the whole hog or just confine myself to the basics ( which are ?). I was informed that the engine would run but, due to certain issues, I never thought it prudent to start it myself. It dripped oil ( nothing new there, could have come from main chain case) and when I removed the magneto chain case cover about an eggcup full of oil poured out ( probably a bush needs replacement). The engine oil was pretty grotty and sludgy. As my first project a bit of advice would be most appreciated. I acknowledge that no two restorations will be the same due to their individual problems and conditional issues. A general steer in the right direction is basically the request.
Thanks for any advice,

Stephen

[SPRIDDLER]

Morning, Stephen.
That's a big question which will no doubt prompt a variety of opinions from perfectionist shed-dwellers to oily-booted riders.
Of no particular significance and just out of interest your earlier posts refer to a '55 G3LS but your Forum name suggests a '46 G3L. Your Profile doesn't say, so which bike are you working on?
Do you have any history from the previous owner? E.g. was he/she using it or has it been languishing in a shed for some time?
As a starter, there shouldn't be any oil in the mag cover. It may be a leaky core/blanking plug at the inlet camshaft (if it's a '55 but the zorst camshaft if it's a '46)) which is simple to sort but I've found that replacement of worn bushes entails splitting the c/case halves.
More later.......probably.

[clive]

To some extent you are going to have to answer this yourself because it all depends on how you think you will use the bike. If you are going to use it for say a 40 mile run once a week April to October you may do 1000 miles a year. When the bike was sold the expectation was probably 5000 a year. If you replace everything that is a bit worn you will have a tight engine and it may take a few years at 1000miles a year for it to ease up. You may be intending to tour abroad on the bike in which case you may want to be much more thorough in you replacement of parts. You decided not to run the engine so you have missed out on some diagnostic opportunities (a stethoscope is a big help when tracking down noises) such as are the main bearings rumbling, is there piston slap when cold, is the big end knocking?
With the engine on the bench I would check/do the following.
Head off, decoke it, check wear on the valve guides, grind the valves in.
Barrel off. How bad is the lip at the top as this will give an indication of wear. If it's not too bad I would hone it out but you could leave it I often have. Decoke the piston, look for wear indicating piston slap. Check the ring gaps. Decide if a rebore is necessary based on your likely annual mileage. Check the small end bush, I have only ever replaced one. Test the big end, should be no perceptible up and down movement (some sideways flex is normal). Check main bearings for and wear or roughness. At timing side check for wear on the timing side bush.
You have already suggested you may need to replace a cam bush. If you decide to split the crankcase don't forget to remove the oil pump first. Check it for wear and the bore for scoring.
Somewhere in the archives there is a WD document which gives all the acceptable wear limits before replacement is necessary.
Happy spannering

[clive]

The Technical specs are under the workshop manuals "1953 Army G3L technical standards"

[SPRIDDLER]

.......it all depends on how you think you will use the bike. If you are going to use it for say a 40 mile run once a week April to October you may do 1000 miles a year. ..... If you replace everything that is a bit worn you will have a tight engine and it may take a few years at 1000miles a year for it to ease up.

As Ken Bryant (aka 'ITMA' of these Forums), an ex AMC dealer frequently wrote: 'A half worn part with maybe 70,000 miles will probably last another 70,000', probably far longer than a pattern replacement'.
His practical article on checking and refurbing a H/W single engine is a worthwhile read:

http://www.jampot.com/article_read.asp?id=161

[G3L1946]

Morning Clive & Spriddler,

Very good advice and suggestions. Pretty much how I was hoping it would go. Mileage per annum? Probably no more than a 1000. Just plodding around North Yorkshire moors and wolds on a weekend. So, no continental trips or lengthy journeys. Looks like I will need to split the engine to replace the leaking bush? Is this right?
I'm pretty much learning this ‘hands on' so all advice is very welcome. I'll save my gearbox questions for another day! Fortunately, I have my late fathers R.E.M.E Maintenance Manual & Instruction book ( book 102/MC2B / MM2B ) for the Matchless single which has proved to be invaluable.
If I can get away without having to split the engine that would be great. But, if needs must!
Look forward to any other words of wisdom you can give,

Regards,

Stephen.

[Group Leader]

Probably no more than a 1000. Just plodding around North Yorkshire moors and wolds on a weekend. So, no continental trips or lengthy journeys.

Sorry I can't provide any advise on what and how far to strip down your machine but you've already got some very good pointers from Clive and Spriddler but one thing I can say from experience is that it is very easy to underestimate how many mile you will cover in a year "just plodding".

The first year I had my AJ I estimated that I would do no more than 1000 miles and insured it accordingly. Two and a bit months in I was on the phone upping the limit and a couple of months later I had to up it again. As I was insured with Hegarty at the time that was very easy to do with no cost implications/fees other than a very modest additional premium. Unfortunately the same could not be said when I went to renew the insurance the following year and be upfront about estimated mileage based on the previous year's experience so I had to take my business elsewhere - their loss!

In 3 years of active riding (most of last year and the beginning of this year being a washout for obvious reasons) just plodding around the local lanes typically doing between 25 to 60 miles per "chug" I've done ~9000 miles! The longest trip was a ride-out with friends in the local Velocette Owners Club (yes, I know) one day when we did ~110 miles but that has been very much the exception rather than the rule.

And I still can't wipe the smile off of my face after all those miles .......

Alan

[SPRIDDLER]

.......your earlier posts refer to a '55 G3LS but your Forum name suggests a '46 G3L. Your Profile doesn't say, so which bike are you working on?

Do you have any history from the previous owner? E.g. was he/she using it or has it been languishing in a shed for some time?

Stephen, it will help to give a bit of background and also to avoid misunderstandings if you confirm the above points in my previous post.

In short, if the oil in the mag drive casing is due to worn bushes (the inlet or zorst camshaft ones depending upon which year of bike you are referring to) replacement of them is possible in theory without splitting the c/case halves but I've never managed it. In theory one way would be with a hacksaw blade or similar being used to cut a segment from the worn bush which could them be collapsed and extracted. However, and among other issues there is a real risk of the swarf from cutting the bush falling irretrievably into the c/case..........never mind obtaining the correct lateral positioning of the new bush which is an interference fit in the casing.
If the oil is just due to a leaky inlet or zorst cam axle core/blanking plug (dependant upon the year of the bike) replacing or resealing the core/blanking plug is much simpler.
The main worry about oil in the mag chain housing is that oil will be dragged up into the mag itself which wouldn't do it any good at all.
Since the chain is intended to be greased and not oiled and the fact that the mag chain cover doesn't have a gasket, the oil will drip onto he zorst pipe and your boot; a feature that I can personally confirm.

Edit:
The inner bush for the axle of the mag driving sprocket has a scroll cut into it throughout its length which is designed to 'screw' any oil on the axle back into the c/case. Wear in the bush erodes the scroll which gradually loses its 'screwing' ability.

[G3L1946]

Good afternoon,

Firstly, apologies to Spriddler regarding answers to his questions ( somehow I missed it as my iPad jumped a message ). My forum ID is simply an acknowledgment to my late father who had that machine and introduced me to the Matchless motorcycle. My project is a Matchless G3LS 1955 ( bought a 1955 as year I was born! ). As to its history, I was reliably informed that it spent its last 15 years in France prior to its repatriation. As to use whilst there, unknown. My observations would indicate that someone attempted a shoddy restoration and utilised non AJS/ Matchless parts when doing so ( these have included John Deere and Lambretta for example with attempts to force metric bolts where they were not welcome). These are being replaced with either original parts ( where possible ) or quality reproductions ( eg. It had a B.S.A. seat which was ill fitting, being only secured at the front, which needs replacing). The carburettor fitted was incorrect. It was an Amal 376/7 which I managed to replace with a 376/5 which I sourced quite economically. I have replaced the main jet and obtained the correct choke slide. Further, the absence of any gasket on the chain case did indicate that oil should not be present, hence my particular interest in solving the issue.
My estimation of annual mileage may be up for debate. Once I get going, who knows!

Kindest regards,

Stephen

[Stuart Jenkins]

Hi Stephen,
Oil in the mag drive cover could be due to the bush being fitted the wrong way round? Easy fix if it is, press out and turn it round.
Hope this helps.
Stuart