Reproduction Speedo’s

Coming very soon!  Grey and black Faced Speedo’s for 2:1 rear drives. Grey face type 26652 and black 26651 $106.42 Canadian each – that’s a lot less in US dollars – check our home page for current conversion rate.

Most British bikes up to the mid 1960’s had 2:1 drive boxes and 500cc twins stayed that way right into the 1970’s.  Grey faces would be used up to 1969 and black thereafter.

The black faced instruments could also be fitted as suitable visual replacements for the chronometric types used up to 1963 but if you do this remember to fit a magnetic type drive cable with the longer top nut

 

20″ Rims and Tires

Quite a lot of British bikes used 20″ rims, especially on the front. Rims we can get correctly drilled for all applications to special order.  We carry 300 X 20 Avon Speedmaster ribbed front tires and also a block pattern 300 X 20 tire by Mitas which will fit front or rear. I don’t think anyone makes a 20″ tube but those for 21″ fit fine.

PREMIER AMAL CONCENRICS

We get asked frequently whether its worth paying the extra for the premier type concentric mk1 carbs.

The regular type are, dare I say it, made much better than they were years ago and do give good service.  As I’ve said many time, the often neglected needle jet is one of the highest wearing parts and quite often rich running can be experienced after say only 10,000 miles.  Replacing these jets on either type of carb usually fixes the problem.

Both types now have stay up floats and the new viton tipped aluminum float needles. The big differences are the very nicely made hard anodized slides and the removable, cleanable pilot jets in the premier carbs.  One nice feature with the regular type is that there is now a  removable screwed plug giving access to the back of the pilot jet and the gas feed passage from the float bowl to the jet. This was previously an area which was almost impossible to clean.

One thing I should mention is that the aluminum float needles (622/197AL) do not work with Monobloc carbs for which you should still use the heavier brass type (622/197).

Nova Scotia vacation

Just returned from a really nice vacation on the East Coast.  My friend Colin Warman in Halifax lent me this beautiful low mileage G15Mk2 and with him on his 69 Bonnie we covered some 300 kms along the beautiful Nova Scotia back roads.  High light of the ride was to drop in at British Cycle Supply where Wayne showed us around.  Mark, the boss, was away but he did call me to say I was welcome to visit as long as I didn’t offer Wayne a job.

Learn Something New every day!

Customer withT120 is having a problem.  Despite both 930 carbs having the same settings one cylinder runs perfectly with a nice cookie brown plug reading and the other plug reads horribly while and lean and that side is running very hot. Recently rebuilt motor so it seems the air to gas mixture (ideally 13:1 approx.)on the problem side is way out of wack. Too much air or not enough gas.

Just like most of us do when we want to find something out or have a problem – we Google it.  The advice he came up with is that the problem is a blocked pilot jet and he should run a drill through it!

Here’s the thing – for anything above 1/16th throttle opening the pilot jet doesn’t affect anything very much.  The mixture is controlled by a combination of throttle cut away (the number is the height of the bridge in 1/16th’s of an inch – ie no 3 slide = 3/16″), the tapered needle passing through the needle jet, and the main jet.

If the needle jet is blocked (very common if gas has been left in the carb for an extended period) it is easy to tell – turning in and out the pilot screw won’t make any difference to the way the bike runs. And flooding needed to get it started.  Hold the carb body with your thumb over the air hole at the back, index finger over the 2 little holes at the front of the slide and blast a shot of WD 40 using the red “straw” down the pilot adjuster hole.  Gas should squirt out of the pick up hole in the bottom of the body.  Good luck if it is blocked. Even if you poke something through the jet (not advisable) to clear it you can be sure there is more sludge in that passage which will block it again.   At least the new carbs now have a clean out plug.

Back to my customer’s problem – if there are no air leaks in the inlet passage downstream of the carb, I would assume he either has a worn slide allowing air to come around the sides, an obstruction to the gas flow or perhaps wrong float height.  The latter is less likely and not as much of a problem as with Mikuni VM’s which I have found to be incredibly sensitive to float height setting.

Fitting Head Gaskets

A customer asked last week what sealant he should use when fitting Norton head gaskets so I took the opportunity to ask some guys who build a lot of motors.

As has been my experience everyone I asked fits copper gasket dry. I always annealed them which I thought might have been overkill even with a new gasket however Les Emery, who worked a lot with copper and brass in his previous life at Lucas, recommends annealing new and used ones and fitting them within 20 minutes.

With the Norton motor it doesn’t hurt to put a thin ring of silicone around the push rod and oil return tunnels in the head and barrel.

With composite gaskets, if they have a copper flame ring they can be fitted dry but if it is steel you should use silicone RTV or similar.

If you feel happier using a sealant, Les uses FIXTPRO engineering grade silicone which he just dabs on with his fingers.

I always used to torque the head down and run the bike for 5o miles or so then torque it again and do the same thing at 500 miles, each time checking the tappet adjustment.  This procedure is more necessary with composite gaskets which are more likely that copper to compress in use.

More on oil

I’ve had some good feedback on this subject and have spoken at length with four customers who ride big mileages on classic British bikes.  By far the most popular oil is 20-50 Castrol GP motorcycle oil.  Two guys reported over 30,000 miles with minimal engine wear.

My friend Gil Yarrow in BC rides huge mileages on his 750 Commando and swears by a bland of 90% 20-50 GP and 10% Lucas heavy duty oil stabilizer.  This he recommends for all bikes apart from late model Triumphs because the additive would not be very clutch friendly.

A couple of guys mentioned Shell Rotella T-Triple 15-40 and one engineer customer swears by 20-50 Spectro 4, which by its ads claims to have the highest content of anti wear additives.