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Well I never mentioned anything about plug chops and for fairly good reasons. For a start you already said you did not know how to read plugs, frankly I doubt anyone does anymore, my self included since the additives in modern fuel play havoc with the colours produced on the porcelain. Also, ideally a plug chop requires a fresh set of plugs each time, that gets expensive. Then, since your looking to check the main jet first your going to be looking for a coloured ring at the base of the porcelain right down inside the nose of the plug. This is because at WOT combustion heat should clean the upper two thirds of the porcelain. So in order to perform your main jet plug chop, you will first need a long stretch of road. Ride to your chosen area and fit your new plugs. Get onto WOT quickly and for long enough to produce your fuel ring, then at speeds well above the national limit cut the ignition and coast to a stop. Remove your now slightly toasty plugs and put them somewhere heat proof, fit your old plugs and ride home. Once home you will need to cut away the nose of the plug in order to see the fuel ring which may or may not be accurate depending what your fuel supplier put in the fuel. Now I don't mean to rant or sound condescending but that sounds a lot more hassle than the simple process I described?

Rod
 

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Hi,

longer ride
Still not happy at idle,
In what way? If the idle varies up-and-down a little on its own, "They All Do That, Sir" :) - no idle stabilisation even in most EI for these old heaps (I think Tri-Spark Classic Twin might include IS but you'd need to confirm if interested). Also as you might've gathered, Amal carbs. are particularly prone to idle circuit blockages. :(

tac is mechanically driven from the front of the engine?
Should be a gearbox mounted on the drive-side crankcase and connected to the end of the exhaust cam.

same arguments about cables apply there?
Usually not so much on the tacho. cable, because it's shorter. However, assuming it isn't original, variable quality has always applied to pattern cables.

actually both gauges which flap about...
Both might simply require their periodic service?

seriously considering getting a pro to take a look,
These guys are 15 mins from my house...
Mmmm ... but how d'you know they're "pro"? absolutely no qualification whatsoever needed to set up as a "Vintage & Classic Motorcycle" servicer, there are Meriden Triumph spares retailers (note I don't use "dealer") with slick websites I wouldn't touch with your bargepole; otoh, any real and good "Vintage & Classic Motorcycle" servicer doesn't need a website because he gets as much work as he can handle by word-of-mouth ...

These bikes become an expensive hobby once you start paying people!
done engine calibration before - but on an engine running on a test bench, connected to a computer.
Rod +1 or no-one nearby with a rolling-road dyno.? Ime, modern ones usually can do exhaust gas analysis with a probe in a silencer and then computer analysis, although it helps if the owner/operator knows at least something about older carburation. If so, once you have your main jets selection (direct from Amal), a dyno. session?

got four bikes in my garage. I've also got a 2 year old daughter so I don't get much time for bike days
Been there, done that, she's sixteen now and very independent. Bike days'll still be there when your daughter isn't 2 any more. :) Can feel frustrating when you're fiddling instead of riding but, as Rod posted, far more satisfying - and more guaranteed - when you diy.

Hth.

Regards,
 

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Discussion Starter #163 (Edited)
I had a look at the tac yesteday. The cable was only loosely screwed in, which certainly won't help! The gauge itself has three bolts/nuts sticking out the back, all of which are loose. This allows the face (and presumably all the innards) to move about within the housing. I had a look on this forum, but all I could see about servicing was sending them away for rebuild. Can't find anything in the Triumph Workshop Manual either. Should I just tighten the nuts? Is there some service task you can perform, other than sending them off for rebuild?

Gonna order the new throttle cables tonight. Planning on getting Venhill ones. It's got a single 620mm cable pointing forward out of the twist and doing a wide semicircle into a junction box in front of the engine, then 400mm cables going to each carb. 'Standard' cables should be OK? The high bar one is 720mm which seems like a lot to 'lose'?

Idling - it's weirdly hit and miss. Sometimes it's steady, sometimes it isn't. Really really struggles coming off of throttle back onto idle, I have to blip like a boy racer when coming to a stop at light, lest I be greeted by silence when I pull up. However, having looked a bit closer, both slides have a tendency to get stuck (and usually stuck in mismatched positions) which probably doesn't help. I'm 99% sure that the cables fault, 'cause if you slacken the cables right off and move the slides with your finger they're very eager to jump back.

P.S. while poking around the cables I also discovered a potential cause of some of my clutch feel issues. The lever bolt isn't present! Amazed I didn't spot that before:D Did triumph specify self loosening fasteners back in the 60s?
 

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Hi,

tac
has three bolts/nuts sticking out the back, all of which are loose.
Smiths speedo. I happen to have loose has two studs and three slotted cheeshead screws. Studs are for mounting, all three screws are tight, each head's on a 3/16" OD steel washer (OD slightly bigger than screw head), each steel washer presses on a 1/4" OD, 1/8" thick rubber washer, the latter presses on a 1/2" OD, 1/16" thick rubber washer contained in a steel cup washer ...

all I could see about servicing was sending them away for rebuild.
Service isn't the same as a rebuild but, same as servicing many other assemblies, covers have to be removed and replaced. BritBike forum has always had some posts/threads by people taking 'em apart themselves but, given most seem include stories of unnecessarily-broken bits and special tools that've been home-made because they can't even be bought from eBay, and service intervals seem to be measured in decades or tens of thousands of miles, I'm happy to accept that limitation.

new throttle cables
out to the garage with my tape measure and confirm lengths
Planning on getting Venhill ones,
Read somewhere recently that their turn-around is very slow, although this might be for special orders?

Been a Venhill user since about the mid-1980's; ime, when they're good, they're very good, but they aren't always good ... Some things I always do to remain a happy customer:-

. Risking stating the obvious, if your bike has low and/or narrow 'bars, route any cable around the front of the frame to the opposite side from the twistgrip (or lever); the desirable large-radius bend will then be maintained even when the steering's turned to full-lock.

. Using that routing, your measurements of at least the outer might turn out to be the same, or close to, an off-the-shelf 'US-market' cable; if so, ime that's (y)

. Nevertheless, also take the time to check the extra length of the inners, make a note of 'em and either include 'em in a written/www order or insist whoever takes a 'phone order notes 'em - again risking stating the obvious, both inner/s and outer/s must be the correct lengths, but some of the people I've known Venhill employ don't always grasp that ...

. I went to Venhill originally because they were then the only company that offered nylon-lined cables. Since they brought out stainless-inner-Teflon-outer cables, I've been happy with them too. If you haven't used the latter before, don't (as many seem to) confuse Venhill's "don't need any lubrication" with "don't need any maintenance at all", I still use one of those cable clamps to blow some WD40 between inner and outer occasionally.

Hth.

Regards,
 

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A word about magnetic instruments - my friend repaired 2 of my speedos this winter showing me what went wrong with particular parts. Most problems is normal wear and tear with a cheaply made instrument on the level of old alarm clock from sixties. No bushing for shafts, broken springs, loose tangs holding tripmeter plastic wheels, soft "monkey metal" of the base, you have to use lathe or a special made tool to safely open and close them without braking glass. Small rubber cushions around the mounting screws are inevitably perished after all these years, so all the innards get full variety of vibrations bike produces all the time.
They probably should be exchange every five years of use for a new part, unfortunately nobody was doing that.
 

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Discussion Starter #166
I think it's probably worth sending the clocks off to Gaggs as suggested by Andytheflyer.

Like most people my age I have half a dozen old smartphones knocking around. The tank has a rack. I'm thinking a GPS app and some cable ties may come in handy:p
 

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Another member was kind enough to ask for a link to this tuning guide by John Healey on the BritBike forum, I've not been able find it for quite some time. If you are unaware who John Healey is, then you will just have to trust that his advise is generally not to be questioned.


Settle down with whatever it is that helps you soak up information and have a read.

Rod
 

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Discussion Starter #168
Might have uncovered part of my throttle problem.

S'actually quite hard to move the outer relative to the inner!

 

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Yes, just change those cables, they are done.
When changing them don't forget to pack your throttle mechanism with grease, same with ferrules of the clutch and brake cables in their levers.
 

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Hi Adam,

When changing them don't forget to pack your throttle mechanism with grease, same with ferrules of the clutch and brake cables in their levers.
new throttle cables
Planning on getting Venhill ones,
Venhill will have either nylon- or Teflon-lined outers; grease (anything including dead dino juice) will bugger nylon lining, won't do anything to Teflon except help to fill between inner and outer with road crap ...

Hth.

Regards,
 

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Discussion Starter #171
My modern bikes have completely 'dry' twist grip internals. Just nylon cams.

They have push/pull throttles too. Brilliant idea:D TBF they're actuating butterflies which is a different motion.
 

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Stuart, I didn't mean cables but their ferrules sitting in brake and clutch levers. They have to move inside their housing, if not cables will start braking near the ferrules. Japanese motorcycles have plastic "bushes" in these places.
Mr Dazzle, I'm happy to hear about nylon cams in your twist grip, but Amal twist grip is all metal and will thank you for some grease with lighter operation.:)
 

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Hi Adam,

didn't mean cables but their ferrules sitting in brake and clutch levers. They have to move inside their housing, if not cables will start braking near the ferrules. Japanese motorcycles have plastic "bushes" in these places.
:) Two nations separated by a common language ... "ferrules sitting in brake and clutch levers" are "nipples" here, "ferrules" are the ends of cable outers.

Amal twist grip is all metal and will thank you for some grease with lighter operation.
Curious. I used to oil them but once found it was causing drag; :( since I've always used some of the cheap spray-on furniture polish I use as rubber lube (and polishing the bikes ...).

Regards,
 

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Discussion Starter #174
I was gonna use cheap PTFE solid spray lube.

Well it's not cheap, it's expensive. But I can 'borrow' it from work;)
 
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