Royal Enfield Interceptor Owners

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Pictures from Redditch (RE 100 aniv.) (29 Jul 2003)

For a good selection of pictures from Redditch, mainly Bullets but some
Interceptors, go to http://home.wanadoo.nl/royalenfield/

Bob Cram

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Interceptor 1A -up for grabs (25 July 2003)

All
I have a 1A sitting in my garage. It has been in storage since 1968. The bike is complete (less battery) and would be perfect for someone with the desire and time to work on it, or maybe just a parts bike.
It is located in Central FL. Any offer will be considered but whoever gets it must arrange for pick up and haul away. It is only worth what someone will pay, all offers considered. I can provide pictures and some information on the bike if any one
is interested.
I am going to place it on EBay in couple of weeks if no one in the
group wants it.
Contact information: Mike Williams

See our Buy and Sell page for details

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Boyer Bransden with a "negative" ground (25 July 2003)

Once again I seek the help of the collective. This question is in two parts. First, does anyone have experience installing the Boyer Bransden electronic ignition on their Mk1A or Interceptors in general?

Second, does anyone know if the Boyer Bransden unit can be installed with a "negative" ground instead of the positive ground that is prevelant on most British machines? I'm looking into converting my Mk1A to a negative ground unit. Thanks in advance.
Rick

I use Boyer Bransden on my Series II; it runs fine and was easy to instal, but has the drawback that when starting, it often will "kick back" when the kickstarter is swung for the first time. BB don't seem to have an answer for this.

Nevertheless it is very easy to time, and has proved reliable. I reckon the engine is a little smoother at high revs, ie comfortable cruising has gone from 75 to 80 mph.
Your best bet to convert to neg. ground (why?) is to ask BB as they probably can supply a neg. unit.
Dave Hollyman

I've never tried one on an Interceptor, but I have one on my Bonneville, and the unit comes with instructions on how to connect it up to a negative ground machine. I'm not sure it is wise to make the conversion though. Anyway, familiar with Brit
machines will assume it is positive ground. If the polarity is accidentally reversed for any reason, it will blow the Boyer, so converting an Interceptor to negative ground and adding a Boyer may be asking for trouble unless the owner can be absolutely
certain that he will be the only one to work on the bike.

Bob Cram

I have a Lucas Rita for a Commando on my Series II and had to make a spacer so the eluctor would clear the points cover (this cured all my hot starting woes, period) if I had to do it over again I would look into a Boyer as this might clear the points cover without the 1/4" spacer.

I also have a Boyer micro digital on my Matchless 650 twin and wired it up negative ground, Podtronics, 3 phase power base alternator as per the instructions and it works just fine showing 14.8 volts across the battery with the lights on.

Mechanics now-a-days are schooled in negative ground machinery and have to wrap their heads around positive ground so IMHO I would think that the chances of a mishap are far greater with a positive ground than with the norm.
Cheers
Rick Fisher

Thanks to you all. The information will be put to good use. The reason for my query is the desire to install a system that conforms to most "on the road" bikes today. One of the items I am installing is an LED tail light unit for both my brakes and tail lights.

This unit is brighter, (added safety factor), and uses much less electricity than the
standard double filament bulb leaving more wattage and amps for my headlight, (hopefully a brighter light than the kerosene lamp that Lucas installed!). And, since diodes are very particular about how the positive and negative lines are hooked up, (has to be a negative ground), the more info I have about a conversion, the better to make an informed decision before I move to the assembly phase.

As of right now it looks like the entire tail unit will have to be floated, (ungrounded
or isolated from the frame). The bike will also sport an RM23 alternator, controlled by a Podtronics regulator, to boost total power availability. I also came into osession of an older installation sheet from Boyer Bransden that explains the hook up of it's MkIII unit in a negative ground environment so that problem is solved. Wiring the
bike will be interesting. If anyone has any tips in this area please don't
hesitate to post it to the web site.

Once again, thanks to you all. I hope the finished product lives up to level of help you've all given.

Rick

I've just returned from travel, and note Rick has been having difficulty in adapting a negative earth replacement LED light to his bike. Here's some insight ...

Rick,
If you are using the stock Lucas tail light unit, take the red lens off and have a look inside. You will note that the bulb socket is actually isolated from earth, because it is held by the molded rubber base of the light unit. The actual connection from the socket to earth is made by a thin piece of braid from the bulb socket to the metal bracket inside the light unit.

So, if you sever that braid, you break the earth connection. Now, you can connect a separate wire directly to the socket, and not have to have it go directly to earth. (This achieves the same thing as floating the subframe, with far fewer complications).

However, I do not think that this is going to help you, since the brake and tail light circuits are both sourcing current, and the common lead from the LED tail light has to sink the current to earth. So, if you have an LED light that's made for negative earth, floating its common (cathode, or negative) lead in order to go positive earth will do you no good, since the polarity is still wrong. If you float this common connection and earth the other leads instead, you cannot connect the common lead to both the brake and tail light circuits at the same time and have the functions remain separate .... (hope this is clear). To do what you need, you must actually reverse the polarity of how the actual LEDs are connected inside the light.

To reverse the polarity of the LED lights, you will have to sever the connection tying the two common (cathode) leads together, and run each to separate wires to act as the connections to the brake and tail light circuits. The other end of the LEDs - the anode (or positive) ends - will then need to be tied together to act as the new earth connection .. bearing in mind that there will be a resistor in series with each of the LEDs, and those *must* remain in-circuit.

Hope this has helped,
.. gREgg

I somehow missed this discussion earlier. Anyway, I just wanted to bring to everyone's attention that there's a guy in the U.S. who rides Triumphs, BSAs
etc. who has developed an LED light that is a straight drop into the standard Lucas signal light and, he says, draws only 1 watt instead of 21. Anyway, he is now working on a similar replacement for the stop/taillight unit.

His website is: http://www.freewebs.com/rtetetet1/index2.html

You won't find the stop/taillight development mentioned at the website though.
I learned that from him in a private e-mail. The website doesn't always work
all
that well either.

Bob Cram

Hi All.

After conversing with an electronics wizard that I know the problem of installing LED tail lights and brake lights on my MkIA has been solved. Actually, the answer was right in front of me the entire time.

The trick is to isolate, (or float as Nathaniel called it), the tail light assembly and run seperate lines to each LED and ground hook up. Since the bike has a positive ground I used the brake light switch hook up,
(two wire), as an isolated switch with one end going to the LED and the to ground. When the switch is activated to ground positive flows to the LED. The Negative is fused through a fuse block and is constant at the tail light. Since the tail light is isolated, (not grounded), problem is solved.

Actually, only the LED board is isolated. The whole unit works beautifully. As a result I've given up the hunt to convert the entire bike to negative ground. Thanks for everyone's input.

Now the question is, does anyone have any experience and tips on hooking
up an RM23 on a MkIA? Will I have any clearance problems, etc?

Rick

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Report from Redditch Dave H (22 July 2003)

Dear Royal,
I was very sorry to hear of your mishap and hope you are mending well. Strange
thing is I always thought HD stood for "Hardly Dangerous" ! Shows how wrong you
can be.

Regarding Redditch Revisited: It was a fantastic event with an estimated 600-700 Enfields present of all shapes and sizes. Truly International for I met Klaus Lackner (rode his Interceptor all the way from Germany and won a concours award!), Anders Lilja from Sweden and Phillipe and Daniel from France.

The Lord Mayor arrived, the sun shone all day at record temperatures of around
29C/84F and many old ex-employees of "The Enfield" came and looked at their
handywork.

Anne Bradford was on hand (if you haven't read her book 'Royal Enfield' put it
on your "must do" list), and Redditch council had provided a fascinating array
of old photos in a marquee.

Spares dealer Alan Hitchcock very generously put up the silverware and
presented it to the deserving winners.

Also there were four Berkeley cars (fitted with 700 RE twins) and other very
interesting machines including a 1950-something Bullet mated to a 1920 'K'
996cc V twin that the owner said went almost straight in! It looked like a
factory job and sounded nice.

An excellant event at which it seemed impossible to move a few feet without
meeting another old acquaintance.

On the Monday following I took some people to Bradford on Avon where we were
given a complete tour of the mines. I'll tell everyone about that in my next
e-mail.

Cheers,
Dave Hollyman

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An old 68 interceptor back in 1985 for $200 bucks. CC (19 July 2003)

FullName: C/C

Picked up an old 68 interceptor back in 1985 for $200 bucks. Started putting it together.but ran out of funds. As far as I know it's a 750 scrambler . City: Phoenix State: Arizona Model1: scrambler,1968 ModYear1: 455 Number1: 455

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After almost seven weeks I'm back. Royal (16 July 2003)

Fellow enthusiasts.
In case you have noticed some inactivity both as moderator of this group and in maintaining our web site www.ozemate.com/interceptor The reason has been a crash on my bike (no not the RE, but HD FLSTS 98 , heritage softail springer).

A 45 min Helocopter pickup, a busted gut, abdominal surgery, 32 bags of blood and other fluids, complex leg fracture (titanium repairs), 2.5 weeks on morphin, etc.

After almost seven weeks I'm back, and I'll have some catching up to do. Just doing well of Canadian crutches.

Welcome to the new group members. So sorry if there has been some delays.
REgards Royal

Dear Royal,

SO sorry to hear about your misfortune! Sounds like you've been to hell, and have come only half way back.

Here's hoping you have a speedy recovery, and there's no lasting ill-effects!

All the best,

.. gREgg

I'm sorry to hear about your accident Royal. That's what you get for riding a Harley ;-). I shouldn't really joke though. It sounds very serious, and I just wanted to wish you well on your continued recovery.

We all appreciate the work you've done on setting up and maintaining the website and listserv even if we don't usually mention it.

Bob Cram

Damn Royal.... You never do anything half way do you! Feel Better Soon!

Rick

Dear Royal

The best wishes for a full recovery are sent to you from Denmark.
Also regards to Kickan who must have had a bad time too !?

What happened ?

Ole

ROYAL,
Best wishes for a speedy recovery.
GLENN

Hi Royal, havent been to the site myself for a while, just read of your accident, wow sounds brutal, sounds like you are lucky to be here at all...that is a BAD wreck, hope your recovery goes well, sounds like you had some spleen issues? 32 bags of blood, incredible..

Have been there myself, t-boned by a Ford pickup in '83 (on HD as well), lost half my left leg, had the bone shortened three times, quite a horror story, gangrene etc., five months hospitalized and I only totalled 17 units of blood..I thought THAT was a lot

Your wreck must have involved another vehicle for that much damage to have occurred..hope you get some compensation out of it if so..

Healing takes a lot longer now that most of us are older.. At the risk of sounding ghoulish I'm wondering how the bike fared.. Good luck on your recovery at any rate, dont let it keep you down
Bob H

Dear Royal,
Here's hoping your recovery will be as swift as that twin engined interceptor on display in the lobby of the National Motorcycle museum in England!

We all wish you well and commend you for your efforts in providing for us Interceptor devotees, the means to share our knowledge of a truly fine motorcycle.
Glad to hear that you didn't break any fingers....
Sincere regards,
Roger USA.

 

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A '63 Interceptor in many, many bits Steve (15 July 2003)

FullName: Steve

Thank you for giving me what is turning out to be a very useful resource. I acquired a '63 Interceptor in many, many bits and am glad to be able to see what I have ahead of me as it comes together. I am also enjoying the "product testing" I know I won't see in magazines. I hope to benefit from your experience. As for the numbers for my bike I'll have to run out to the garage when I have some daylight.

Thanks again! Steve

City: Jacksonville State: Florida Country: USA Interceptor, 1963

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I manufacture various spares for Enfields (13 July 2003)
FullName: Gautambhai

Message: Dear Sir,
I am in India and travelling to Sydney for some weeks. I have been involved with Enfields since last 50 years. I manufacture various spares for Enfields. I am keen to meet you people in Australia. Can you please give me your address and phone numbers.

Best Regards.
Gautambhai.P.Sachania. City: Sydney State: NSW Country: Australia Model1: 1958 Model

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Amal concentric float levels (13 July 2003)

Is there someone out there knowing about amal concentric float levels? I have a lot of those nylon floats and pins and (not to my surprise) they all give different levels. Probably bent by old age..

But what should the correct petrol level be for an Interceptor? I once tried one of those bronze / Viton pins. Got the impression that they lower the level some mm. (I suppose by not floating on the petrol like the nylon ones.. and the play in the connection to the float-arm.

Paulus

Most of my knowledge of this comes from Triumphs, which use the same carburettor. Gregg might know if the RE setting is supposed to be different. With a Triumph, you want the float to rise to 1/16" below the top of the float bowl, so that's probably at least a good approximation for the RE.

You can check how far it rises by holding the float bowl with pin, float, etc. all in place. Include the gasket, because the pin rises up to the point at which the gasket holds it down when the float fills with fuel. With your thumbs firmly on top of the gasket where the pins meet it, turn the float bowl upside down and see how far the float falls.

You may want to have a second person handy to mark the spot on the inside of the bowl with a marking pen. Then you can measure it.

You'll note that the float needle sits in a little brass piece pressed into the bowl. You change the float height by moving the brass piece up or down. This can be done by very gently heating the float body, and then you'll find you can move the brass piece. I've done this on a stove with an electrical element. I put the heat on its lowest setting, a pot on the burner, and the bowl in the pot. An oven mitt is useful for holding the bowl.

Bob Cram

The correct float level is set by the design of the carburettor rather than the engine ... unless of course there is something about the mounting on a specific bike that dictates an alteration. For instance, if the carb is mounted at a severe downdraft (like a Goldstar), then the level will need to be reduced to prevent flooding. No such problem with our beloved Inters, though.

I'd be cautious with adjusting the fuel level by moving the brass seat. It is designed to take its seating against a machined register, and there is a good chance that heat a vibration will cause it to move back to its original location over time.

I've found that incorrect fuel level is most often caused by an old float whose tang has fatigued. Replacement is the only sure answer.

Hope this helps,
.. gREgg

Except on my dual carb Bonneville, I found that the float settings were quite different on each carb, which threw off the carb balancing. In such cases I don't think you have much choice but to adjust the float level. The adjustment I did has been fine for about 5000 miles. I usually give them a quick check anytime I have the bowls off, and they haven't moved so far.

Bob Cram

I should have been more clear about what I meant.

I was cautioning against simply moving the seat away from its register in
the float chamber to effect a change, because of the real possibility of it
reverting to its old resting spot. It would be far better to:

1. replace the float with a new one having a tang that had not fatigued, or
2. remove the seat from the chamber, and add a perforated shim between it
and the bottom of the hole before pressing back in.

As you have suggested, it is prudent to heat the float chamber first.

... gREgg

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Questions on clutch and gearbox. (9 July 2003)

Hey Gang,
I joined the group last winter, and have been fortunate to just find an Interceptor project. Believed to be a 1968 1A, steering head is stamped 73512, left side of crankcase is YC 16971, gear box and front left of crankcase both with AGZ 2731 (is this the engine number?).

This bike has passed through several hands since 1982, has not run since 1982, and may not have run since before that. Good reason through receipts and sighting through the plug holes to see that new pistons, supposedly .040, and valves are present. Alot of missing or dismantled equipment, so the search is on.

A few initial questions for group wisdom, concerning the clutch and gearbox. eceipts show new cork and steel plates circa 1983, but does anyone have an idea of service limit thickness of cork plates, and am unsure whether the steel plates are suitable for reuse as they acquired surface rust and minor (?)pitting from sitting. I've cleaned up one fairly succesfully with 220 paper under a stream of kerosene in a parts cleaner - but would be interested in whether you folks think this is false economy.

Also,any thoughts on Hitchcock's being out of clutch springs and the advisability or not of using different gauge springs from other Enfields? And one (temporarily!) last question: the locknut for the spring-loaded detent plunger accessed under the outer gear box case (upper left above main shaft bearing cover), identified cryptically as "spring box locating plunger", is missing, so the question is how to properly thread in or out this detent plunger properly? Thanks folks, hoping to pester or entertain you with plenty more questions later.
Best,
George Little (Vermont)

Hi George
Are you sure Hitchcock's are out of springs? My manual lists 3 different gauges
for Interceptors. 12-13-14 ga. If they are out of all ga. I have a set of 13 ga (0.091th) I bought from them last year. But try all three part numbers first I just checked their web site and they only say they are out of one size.
Good Wishes
Orlan

Hi george saw your e-mail about aquiring a 68 re 1a .i have a 67 re 1a .i'm
finally on the road with mine after alot ofhunting for variuos parts and
literature .sam avellino was a great help to me .

He is located in revere ,mass . your neighborhood .i purchased many hard to find 750 parts from him along with his knowledge of these old brit bikes he's the guy to ask where and what in regard to getting another interceptor back to life. give him a call he's very helpful and a great guy .

Tell him i sent you on his trail . sam avellino 240 harris st. revere, mass. 02151 phone ;781-284-5157 no web site no credit cards he's an old fashioned business guy. glad to help and point you in his direction,ken smith penfield ny p.s. hell give you price quotes over the phone.
good luck
Ken

George,

Judging from the engine number (YC16971) you've quoted, I would say this is not a Series 1A, but rather a late-ish Series 1. I can't seem to put my hands on the cheat sheet I use for gauging the dates of the twins, but from memory I would say that this is a 1965 machine.

Check the left side of the engine, just below the cylinder base. Does it have two round alloy covers about 2" dia. bolted on, which cover the ends of the camshafts? If so, it is not a Series 1A. There are numerous other details, but those are the easiest to spot.

The other detail to help date the machine is whether the speedo and tach are out in the open, or if they are both encased in a cast alloy fork crown. A Series 1A has the speedo and tach attached to a metal plate, which fastens to the top of the fork crown. The earlier machines had various forms of alloy crowns that encased the instruments.

Also, a Series 1 has a proper tool box unit behind the engine, whereas the 1A has none, with the battery mounted transversely on a formed sheet metal platform, behind the engine. If you want, I can forward a high res photo of my Series 1A, which is fully restored, but happens to be about box-stock in appearance.

In terms of the "spring box locating plunger", set it for the lightest pressure that results in positive shifting. In point of fact, you can't screw it in all that far before it gets spring-bound and jams anyhow. Bear in mind the correct locking nut is a half-height nut.

The slight rusting on the steel clutch plates should not be a worry as long as they are not too rough. Sand them flat, but be certain the tangs on all the plates are in perfect condition, or you will have difficulty with the clutch not releasing. Similarly, the splines on the clutch center must be perfect, as should the slots in the clutch basket.

Hope this helps,
.. gREgg

Thanks to everyone for all the help, with a special nod to gREgg's seemingly endless knowledge and friendly advice. It appears that this may be a very early 1A - the numbers may even suggest a 1, yet the engine and chassis indicators are distinctly 1A. Might someone with a 1A of known vintage be able to compare their frame and engine numbers with those on this bike, 73512 frame and YC16971 engine?

Armed with much information from y'all, I'm hoping to fine tune the undoubtedly first of many lengthy parts lists this weekend, though that should properly be 'spares' or 'bits'! Otherwise, just a quick-and-dirty thought, if it even deserves that dignified
a term, after inhaling the RE Knowledge Base, thinking here of the fascinating oil pressure/supply discussion: the symptoms of good initial pressure cold and poor hot are often found in automotive engines with cam and rod journal clearances at the high end.

Yet there appears to be no significant discussion of these as RE problem areas, so just tossing it out for the next of us to possibly check off our lists before jumping ahead to re-engineering . . .
Best,
George in Vermont

Hello george ; i have a 1-a 750 the frame #73249 engine # yc-16855 gear box
case # is agz 2754 from what i've learned from all the talk on the oil pressure
is not to worry if you have the older oil pump design such as in the 67 and
earlier pump configuration . does your 750 have single or dual points? that is
magneto or coil ignition .

good luck, k smith

Thanks so much K(en?),
reassuring that the numbers are not so far off for a 1A - what year do you
have yours registered/titled at? Supposedly mine is a 1968, though wondering -
depending on what you say - if it might not be a 1967. It does have
distributor/coil, not magneto, ignition.
Best,
George

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Exhaust valves were wearing very fast. (8 July 2003)

Some year ago I gave my Interceptor a set of new valves.. later I found out the exhaust valves were wearing very fast in the guides. When I looked better I found out that the valve geometry wasnt quite right.

The exhaust valves were 2 mm longer than they should and that meant that the rockers were hitting them off center and pressing them to the top / side. So I turned off 2 mm on my lathe and replaced the spring on the rockershaft with some shims to get a minimal play to the sides.

Paulus

This is a more common problem on Brit bikes than most people believe ...
"correct rocker geometry" as it is called ... is especially a problem with Nortons.

Correct rocker geometry is achieved when the valve is at half lift, at which time an imaginary line through the center of the valve adjuster tappet should pass exactly though the centerline of the valve stem.

Achieving this state usually calls for adjusting valve length, and or the length of the push rods (Did you know that there are at least 3 different push rod lengths used on Enfield twins ?)

Getting the hardened ends off the push rods is not easy, and to so I built a special jig/tool that fits in my press. A bit of a fiddle, but the results were well worth it on my Series 1A,

Another tip: take care not to mix up the push rods. Once the mating ball & socket ends have worked in together in a particular way, they will be too loose or too tight if mated with other parts. I measured some with radius gauges, and was quite surprised by the variances in radius from one ball & socket to another. This probably accounts for why some top ends are noisier than others.

.. gREgg

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Engine Breathing. (8 July 2003)

Here is another one that comes from Captain Norton, but suits our Interceptors well..

When pistons move up and down they create underpressure resp. overpressure in the crankcase. Overpressure we don't like because it presses the oil out though every hole there is.. and that gives an sweaty engine.. and oil being sucked though the valve guides into the inlet channel. Underpressure we like because it keeps the oil in where it belongs.

On the Interceptor there is just a big hole and a flexible hose to let all those pressures out. To keep the underpressure in you can put a valve in the hose. Captain Norton advises Motormite Power Brake Check valve nummer van GM # 18022219 (motormite Help! Products 80190)or Volkswagen.. VW part no. 191 611 933. I went for the Volkwagen valve and seriously.. no more sweating om my
engine.. hope it dosn't get rusty now..

Paulus

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Boyer Digital. (6 July 2003)

I changed my old Boyer mk 3 to the later digital type of Boyer electronic ignition. The old one is not very sophisticated as it advances in a straight line, while the digital one makes a real curve .
It proved money well spend.. acceleration is better, but more important the idle is very much improved thanks to a electronic stabiliser. Because Enfield (like Norton) has a chain driven ignition mounted on the camshaft the idle is very difficult.. at least it was on my Interceptor.. But now it is a delight.. going very slow and stable. But.. an unstable idle can also be the result of an idle jet that is dirty. On the captain Norton site you'll find advice how to clean this microscopic little thing which is hidden deep in the inner parts
of your Concentric.

Paulus

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Some clutch questions. (3 July 2003)

Dear Interceptor friends
Some clutch questions:

How do you easily identify the two different springs? One are strong and one weak. I can not feel any differnce by just compress them by hand.

How should the inner and outer dished plate be fitted? Inner dish should be projected outwards the outer inwards. Could anyone explain this in other
words please.

All the best
Anders

Hi Anders
I am not an expert but I have some experience on this clutch, and if I am
wrong
someone in this group will know the answer.
As for the springs, the light ones seem to measure at 0.091 th and the
heavy measure at
0.100 th. I do not alternate as the manual says to do. I run all of the
heavy ones.
After securing the clutch sprocket with the large circlip The order of the
of the clutch plates as follows
1 - Plain dish plate (dish projecting outwards toward you)
2 - friction plate
3 - plain flat plate
4 - friction plate
5 - plain plate
6 - friction plate
7 - plain dish plate (projecting inwards away from you)
8 - friction plate
9 - centre retaining plate
10 - front plate
11 - distance pieces and springs
12 - spring cap
23 - three spring pins

Hope this helps
Orlan

Anders,

I've been abroad for the past week, and it doesn't look like you have had an answer to your question, so here goes.

1. Springs. The easiest way to check the springs is to measure the thickness of the wire with a caliper. The weaker springs are wound from thinner wire. The other way is to put pairs of springs between the jaws of your vice, and tighten the vice slowly. The weaker spring will compress more than the heavier one.

2. Clutch plates. The easiest way to remember the correct orientation of the clutch plates is as follows. Note that the raised part of the inner and outer plates must face each other. Thus, the plates are closer together where they are dished.

Maybe some ASCII art is in order to illustrate what I'm getting at:

Clutch Plates
Inner Outer

| |
| |
| |
\ /
| |
| |
| |
/ \
| |
| |
| |

Hope this helps,

.. gREgg

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