Oil pressure gauges

We are frequently asked about the availability of external oil pressure gauges. While we can get one which is fed off the rocker feed line for Norton twins from engine number 116372, it is not something I recommend. I had a friend many years ago who had one on on his Triumph twin and the vibration cracked the copper line, spewing oil everywhere and he almost crashed his bike. This last week we were contacted by a customer whose motor had seized up because he didn’t notice that the line to his gauge had fractured causing a loss of oil and pressure.

The idiot lights fitted some bikes are a good idea but the cause of many bottom end failures is a blocked sludge trap and there’s no pressure gauge to warn you of this. Before going for a ride it is a good idea to check your oil level and even take the cap off the oil tank to be sure the oil is returning nicely – on early Norton twins you were even advised, in the owner’s handbook, to put your finger over the return hole when starting the bike cold, to divert oil to the valve gear.

Here’s an interesting bit of advice I received yesterday from an actual mechanic. There’s no need to pre-mix gas for your two stroke chainsaw or weed eater. All you have to do is fill it with fresh gas, start it up and the progressively add oil until you see smoke. Makes you wonder.

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Wheel Building

Despite several articles in the periodicals I seriously believe this is a subject left for the professionals and should not be attempted by amateurs.  We are representatives for the Central Wheel Company in England and sell literally hundreds of rims and thousands of spokes every year. Almost every day we get retail customers calling who claim that the rims or spokes they have bought from us are incorrect, many in frustration demanding that we pay the return shipping on the defective parts.  Our standard answer used to be to tell the customer to return the rim, spokes and hub to us.  If it was defective we’d correct the parts a pay for the build, if correct the customer paid.  Unfortunately our friend and good wheel builder, Jock Graham, passed away recently so we no longer offer this service.   Over 90% of the parts returned had nothing wrong with them.

I am not a wheel builder but when necessary have always been able to lace them up OK for my own bikes.  Here’s the tip I give to customers having difficulty, including several claimed to be experienced builders,  and from the feedback it seems to work.

Forget about the dozens of pictures you took of your original wheel.

Lay your hub on a flat table and place the rim around it chocking it up on books or whatever to get it in the approximately correct position (I hope you measured the offset before you took it apart).

Take 4 spokes and thread nipples onto them.

Push the spokes into the rim holes with your thumbs and by seeing where the spoke heads “default” to you will be able to move the rim around, turning it over if necessary, to get the position right.

Now you have identified which drillings go where, get your inner spokes loosely installed, followed by the outers.

Final truing is for sure best left to the professional, the importance being to tension all the spokes evenly.  This is best done by feel and experience.  Central  Wheel tell me that in 100 years in business they have never had a spoke torque wrench on the premises.

TAPS AND DIES

We only carry as regular stock top quality taps and dies in HSS (high speed steel).  These are more expensive than regular quality but are designed for the professional.  We recently had someone make some special 3/8 grade 5 BSF bolts for us and they were able to produce over 100 using one of our dies.

We have for years carried CEI (26tpi), BA and BSF taps (taper and bottoming) and dies as individual items and in boxes sets.  We also carry BSP taps for gas tank threads.

In response to demand we have now introduced the following boxes sets (again all HSS).

BSA Set  0 -5 BA (20 pieces) Part No 99-22 $175.55 Canadian.

UNF Set 1/4 – 1/2″ (17 pieces) Part No 99-863 $255.00 Canadian.

 

Ignition Timing

Customer with late coil ignition model Matchless G15CS – very similar to N15CS, Atlas & P11 – even early Commando – wanted to know if I could give him a measurement so he could stick a rod into his plug hole to set his timing.  Here’s my reply…

That would not be accurate enough because a piston doesn’t go down the bore at distance exactly in synch with the rotation of the crank and also the plug threads are not exactly 90 degrees to the piston top.  Also piston crowns vary a bit in height which would mean a differing starting point.

Add to this, the optimum timing varies according to the gas you regularly use.   These bikes were originally designed to run on 98 octane fuel – much higher than that presently available.   I would suggest you set the timing according to the specifications and then

take it for a ride.  If on roll on acceleration from say 40-50 mph you hear and sound of detonation (pinging) then rotate your pick up plate say 1/16″ in the direction of rotation of the magnetic rotor and try again.  This will effectively retard the ignition slightly.  Keep doing this until

you get rid of the detonation.

We do carry and contact breaker mounted timing disc (98-0818CEI $27.55 Canadian) which you would find useful for this purpose.

 

Fuses

A customer asked if there is a difference between UK and North American fuses. Here’s my reply:

Absolutely!  British fuses are rated by blow rate and North American by flow rate.

A 32 amp British fuse is designed to carry a current of 16 amps and will blow at 32.  An American 32 amp fuse is designed to carry a current of 32 amps and won;t blow until it is substantially higher than that.

Fit a 32 amp American fuse to your British bike and if you get a short (quite common on BSA’s from my personal experience) you will be at best buying a new harness and at worst putting out a fire.

 

NORTON GEAR OIL

I hear the forums are buzzing with “expert” advice on Commando gear oil.  The rumour is that GL5spec 80/90 or 90wt  extreme pressure gear oil will damage the bushes in Norton gear boxes.  We have been selling BelRay 80/90 GL5 for years to Norton owners and are not aware of any problem so I referred the matter to the most experienced Norton mechanic I know of in the UK.

Here’s his reply:

“It’s a load of rubbish.  I have stripped and rebuilt many hundreds of Sturmey
Archer dolls head, upright, laydown, AMC and both types of lightweight twin
gearboxes and always use 90 or 80/90 oil without ANY problems.”

NORTON FORK DAMPING

Norton Roadholder forks are fitted to Domi’s, Singles, Commando’s and also to several 1964 onwards AJS & Matchless models.

This is a very good design and when in good condition give excellent performance. One of the biggest complaints is that they lose damping performance, as evidenced by the “clunk” at full extension.

There are several internal devices on the market to improve the performance of these forks however the damping problem is usually caused by wear in the alloy damper caps (Part No 06-1347). The damper rod passes through this cap and the rod to cap clearance should be .002″ approx.  These caps do wear and clearance of .020 – .030″ is common, providing very little restriction to the flow of oil, which controls the dampening.

More about oils

I have discussed several times the unsuitability of modern oils in classic cars and bikes with their big flat tappets and larger running clearances etc.  The problem is mainly due to the lack of zinc in the oil, which for our purposes needs to be at least 1200ppm.

We have now started carrying this engine treatment additive from Hipertech (Part No H100350 for a 350ml bottle).  Adding just 35ml to each liter (that’s about 100ml for the average oil change) will bring the zinc level in your regular oil up to at least 1500ppm.

The product’s primary benefit is to reduce friction thereby reducing wear and ensuring long and reliable engine life.   It also helps by protecting against viscosity and thermal breakdown, enhances rust protection (important in vehicles which go for long periods without starting) , improving power and compression and lowering oil consumption.

 

 

 

 

 

 

BRITURO CO UK

We have dealt with Brituro, who make mufflers for us,  for close to 30 years and there is a rumour going around the internet discussion groups that they have closed down.  Joe Dallow assures me that this is not the case.  They delivered an order of BSA/Triumph “Ray Guns” and other mufflers to us a couple of weeks ago.