Restoring & Modifying 1971 OIF TR120

[NM Bonny]

On the kickstand repair, here are the lugs I found:

The first is no. 83-0035, which can be had for $31, and may be a cast item(?). The second is sold by Old's Cool Choppers for $37 and looks like TIG-welded mild steel.

The notion you can't kick start a motorcycle on the side stand is... well, idiotic. I have owned a half-dozen kick-start bikes including the 565 lb. '51 FL that have never had an issue. (Though to be fair, the Harley has an over-engineered, spring-loaded side stand that bolts to a plate welded to the frame tube.)

That said, this appears to be a Meriden design weakness that shouldn't be too difficult to overcome.

Assuming that the typical failure is where the lug meets the semicircular (or circular) frame butt, three measures would presumably solve the issue:

1. extend the length of the frame butt if possible;
2. extend the length of the lug fore-aft to exploit the lengthened butt; and
3. add two pairs of gussets to stop the flexing along the plane where the lug is cast or welded onto the butt.

I would think the torsional strength of the OEM frame tubing should be more than adequate to withstand the transferred twisting force... but does anyone know the wall thickness of the OIF frame tubes at this point?

 

[Rudie]

pulled the plugs and laid them atop the fins so the threads were touching, kicked the bike and got a little blue-white spark on both cylinders.

no dice.
bike fired one or twice, and there seemed to be a minor backfire, she wouldn't run.

Ime, typical of any carburetted engine that has not been used for a long period, I just keep tickling and kicking, the "minor backfires" turn into longer and longer period of firing until it eventually just runs.

Btw, you are holding the throttle open a little when you kick, are not opening the throttle as you kick?

worried that I might have timed the BB ignition to no. 2 cylinder

Not relevant on a 360 degree 4-stroke twin; BB (almost all e.i. for British twins), coil for each cylinder is connected in series to the electronics' single switched output (Black wire on any BB), so the power to both coils' primaries is switched off when either cylinder is on its compression stroke and needs a spark; is the reason the e.i. are known as "wasted spark".

figured I'd flooded the cylinders.

Yeah ... ... I can tell that has happened when the "minor backfires" stop ... I just hold the throttle wide open, kick the engine over half a dozen or so times, let go of the throttle, tickle the carbs again, hold the throttle open a little again, start kicking again.

kick stand's ugly welding job that the broker did busted.

could not find a scratch anywhere on the bike.

The notion you can't kick start a motorcycle on the side stand is... well, idiotic. I have owned a half-dozen kick-start bikes including the 565 lb. '51 FL that have never had an issue.

This is a 53 year old Triumph, simply Meriden never at any time engineered the sidestand frame lug for the stress of the engine being kicked over. When your bike was new, iirc the US guarantee period was either three or six months, anything that broke anytime after the guarantee ended was the owner's problem.

Kicking the engine over with the bike either upright or on the centrestand (I do the latter) is hardly a chore? It is just something you either accept as part of owning an old Triumph or you strengthen the bike's sidestand lug.

BB's reference to clockwise vs. counterclockwise mean as viewed from the ignition side

Correct.

coils
Perhaps one or both is faulty
pulled the plugs and laid them atop the fins so the threads were touching, kicked the bike and got a little blue-white spark on both cylinders.

Does not sound like it? Only possibility is both plugs are not firing under compression?

One tip I received decades ago, still use when first starting an engine that has not been used for a long period, is close up the plug gaps to, say, 20 thou; after the engine starts and runs, open the gaps back out to 25 thou.

check the coils against the specs in the manual.
guessing (though I don't know) the PO had installed two 6v coils...

With the BB analogue e.i. (black Transistor Box), "6V" coils must have a primary resistance between 1.5 and 2 Ohms; less than 1.5 Ohms, too much current is drawn through the electronics, they fail prematurely; much greater than 2 Ohms (e.g. 2.2 Ohms of old PVL coils is fine), too little current is drawn, spark problems, particularly at higher rpm.

BB says:
"For low compression engines, two 12 volt coils (4 Ohm Resistance) in series are satisfactory,

Ime, while BB fitting instructions have always said that, is complete rubbish, never works, irritating nonsense. I first dealt with Bransden Electronics long before there was internet, they offered tech advice on a dedicated phone number between 4pm and 5pm. If you phoned about an ignition problem on a twin, one of the early questions in the conversation would be whether the bike had 12V or 6V coils; if the answer was 12V, the advice would be to fit 6V, call back again if there was still a problem ...

Btw, your photo. View attachment 59205, I never use those red insulated terminals, I have replaced too many on other people's bikes at roadsides and in campsites. Between what BB calls the "Stator" and the Transistor Box, I use "Japanese bullets" and sockets; because both terminals have an insulator, pushed together with the terminals the insulators make an almost waterproof seal. The larger 3.9 mm (aka 4 mm) bullets/sockets are widely available but the 3.5 mm are also slightly shorter, wires do not have to be bent so sharply inside the timing cover and, if the bullets are fitted on the wires through the crankcase, those wires can be pulled out of the crankcase without cutting off the bullets. Available from Cycle Terminal.

 

[NM Bonny]

Rudie - thank you, again, for your generosity with the thorough responses.

- Kickstand: I hear you. I'll either have to reconcile myself to reengineering or simply more sturdily repairing the side stand lug, or stripping (partly?) the frame to realign and bolster the center stand lugs, (or both). The latter two options may mean this project will be on hold until next year...

- Starting technique: I think that I was opening the throttle as I kicked. Assuming I can figure a way to safely kick the bike on the lift (was thinking about a stabilizing solution last night) or repair the side stand before it's too cold and I have to drain the tank to avoid a load of yucky gas, I'll try your technique.

- Ignition: okay, I will check the coils with my multimeter, then check the plug wires for resistance as well. I think I have a second set of new plugs, so can always swap those out to eliminate the possibility of a bad new part (it happens). I'll try tightening the plug gaps a little bit, too.

Good idea on the leads to the BB--and thanks so much for the link to the better terminals. I've ordered some and will rework the leads to make sure I'm getting good connections. I don't mind kicking, but makes no sense until you know your connections are copasetic!

Yes - the '51 FL is also a 360 crank, wasted spark setup--but appreciate the reminder. In fact, the single, twin-lead coil I use with its electronic ignition would work just fine on this bike. But I like using the existing, rubber-mounted coil setup under the seat. For now, anyway...

 

[atomsplitter]

- Starting technique: I think that I was opening the throttle as I kicked. Assuming I can figure a way to safely kick the bike on the lift (was thinking about a stabilizing solution last night) or repair the side stand before it's too cold and I have to drain the tank to avoid a load of yucky gas, I'll try your technique.

The issue is you have the wrong kind of lift.......

 

[NM Bonny]

The issue is you have the wrong kind of lift.......
View attachment 59211

Yeah, really. Problem is I don't have room for a big dedicated lift like yours. Very nice!

 

[Rudie]

Rudie - thank you, again, for your generosity with the thorough responses.

Pleased it is helping.

think that I was opening the throttle as I kicked.

No accelerator pump on Amals.

multimeter
check the plug wires for resistance as well.

Will not tell you anything unless a plug wire is broken completely. Checking resistance, it is the meter's battery that powers the circuit, if you are lucky, the battery is 9V ... Just one strand of a plug wire could be unbroken, the meter will tell you no resistance; however, when the plug gap needs five figure Volts for a spark ...

don't mind kicking, but makes no sense until you know your connections are copasetic!

As you can see the plugs sparking when you turn the engine over, no problem now with the connections between BB Stator and Transistor Box. What I do not like about those red insulated terminals (and the blue and yellow ones) is ime they are just not long term reliable.

Remembered another gotcha with BB ... they sometimes connect the Stator wires the wrong way round ... you connect Stator Black/White to Transistor Box Black/White, Stator Black/Yellow to Box Black/Yellow, you see sparks when you turn the engine over ...

... but, because the wires are connected "wrong" for the Box electronics, the sparks timing is miles out ... If my "keep tickling and kicking, it will start and run" advice really is not working, try swapping the Black/White and Black/Yellow connections at the Stator or the Box ...

FL
single, twin-lead coil I use with its electronic ignition would work just fine on this bike. But I like using the existing, rubber-mounted coil setup under the seat.

The standard OIF coils mounting was developed for the first triples two years earlier, absolutely no problem on them.

Only thing you have to watch on early OIF like yours is the coils are mounted vertically, the vibration can be enough to knock the bottoms of the coils against the fender, wears a hole in the coil, all the cooling oil runs out ... Aiui, a later OIF coil mounting tray, that mounts the coils at an angle, so the bottoms are further away from the fender, will fit.

If there is a downside to a single twin-lead coil on an OIF, it is you then have to devise a mounting as good at isolating the coil from vibration as the (later) standard Triumph mounting. That said, I believe Emgo offers a twin lead coil the same diameter as a Lucas 17Mxx coil?

 

[NM Bonny]

Pleased it is helping.


No accelerator pump on Amals.


Will not tell you anything unless a plug wire is broken completely. Checking resistance, it is the meter's battery that powers the circuit, if you are lucky, the battery is 9V ... Just one strand of a plug wire could be unbroken, the meter will tell you no resistance; however, when the plug gap needs five figure Volts for a spark ...


As you can see the plugs sparking when you turn the engine over, no problem now with the connections between BB Stator and Transistor Box. What I do not like about those red insulated terminals (and the blue and yellow ones) is ime they are just not long term reliable.

Remembered another gotcha with BB ... they sometimes connect the Stator wires the wrong way round ... you connect Stator Black/White to Transistor Box Black/White, Stator Black/Yellow to Box Black/Yellow, you see sparks when you turn the engine over ...

... but, because the wires are connected "wrong" for the Box electronics, the sparks timing is miles out ... If my "keep tickling and kicking, it will start and run" advice really is not working, try swapping the Black/White and Black/Yellow connections at the Stator or the Box ...


The standard OIF coils mounting was developed for the first triples two years earlier, absolutely no problem on them.

Only thing you have to watch on early OIF like yours is the coils are mounted vertically, the vibration can be enough to knock the bottoms of the coils against the fender, wears a hole in the coil, all the cooling oil runs out ... Aiui, a later OIF coil mounting tray, that mounts the coils at an angle, so the bottoms are further away from the fender, will fit.

If there is a downside to a single twin-lead coil on an OIF, it is you then have to devise a mounting as good at isolating the coil from vibration as the (later) standard Triumph mounting. That said, I believe Emgo offers a twin lead coil the same diameter as a Lucas 17Mxx coil?

So, no harm in reversing the leads to the stator? Perhaps it's the box I'm thinking of that you do not want wired incorrectly...? (I'm set up for negative ground.)

Yes: I noticed the coils being awfully close to the (freshly painted) fender. Now that I think about it, it'd be an easy matter to make some aluminum circular shims to lift the coils up just a touch--and they'd still be resting on their rubber doughnuts.

On the plug wires... for some reason I seem to remember a more comprehensive way to test plug wires. I'll have to hunt around and refresh my memory.

 

[NM Bonny]

On the side stand issue...

I posted the two repair parts available earlier, and thought this one might be more heavily constructed than part no. 83-0035. But now that I think about it, the thickness of the lug is likely to be the same, as both have to slip into the OEM kickstand lever.

Anyway, I have marked up the other option to show where I would add gussets that I think would eliminate (or vastly reduce) the possibility of the lug tearing off of the butting which encircles the frame tube.

It looks to me like the broker (who had bragged about his welding prowess in making this repair) simply held the broken lug back in place and added welding wire (or rod) along the seams of the existing tear.

Well, in looking at the third image here--part no. 83-0035--the butting which extends up around the frame member is longer. I don't know whether they intend you to heat those and bend around the frame tube before welding all the way around--or just make a fillet of weld in there.

Regardless, the longer arms of the butting would make it easier to fashion gussets as drawn into the first image. The 'no fun' part of the repair will be removing the existing butting without damaging the frame tube.

Of course, the alternative is to get some appropriately-sized mild steel tube and a chunk bar and fabricate my own custom, much longer repair lug... or, hey, I could just get some tube and bar and extend no. 83-0035. That would let me practice per the following question...

Question: does anyone know the tubing wall thickness on these frames? I would like to buy a small length of mild steel tubing to experiment with the MIG welder on its lower settings before applying a bead to this tube and potentially blowing through...

 

[Vector]

The broker can’t weld worth a darn.

 

[NM Bonny]

Well I can't find any discussion of wall thickness; just some mention that the frame tube used for OIF bike frames was Renolds 531. Probably, speculates one guy, .065~.095" wall, i.e., 'thin wall' mild steel tubing.

I'll try to hunt down some information for similar model/year bikes, but if after doing some practicing I am blowing through the material I settle on to extend the butting, I may have to have my machinist's welding specialist come do it.

Turns out that TIG welding may not be the best method per one discussion I found. Torch welding seems easier on the metal, avoiding the potential for introducing brittleness into the surrounding area--at least per one engineer discussing welding on an OIF bike.

We'll see. The materials list on my MIG welder says it can go down pretty darned thin...

 

[Rudie]

no harm in reversing the leads to the stator?

No.

box I'm thinking of that you do not want wired incorrectly...? (I'm set up for negative ground.)

As you probably know, ground does not affect how DC works; all e.i. makers' wiring diagrams always show the electronics box between the battery negative terminal and the coil(s), irrespective of ground.

BB, negative ground:-

. I connect the Box White wire through the 5A fuse directly to the battery negative terminal;

. multiple coils, the Box Red is connected to the positive terminal of the last coil in the series, that terminal also connected either to the kill switch or (kill switch not fitted) to the ignition switch.

noticed the coils being awfully close to the (freshly painted) fender. Now that I think about it, it'd be an easy matter to make some aluminum circular shims to lift the coils up just a touch

... unfortunately, BSA/Triumph built another gotcha into the OIF, all the electrical components terminals are already very close to the steel seat pan ...

Long time 71 OIF owner I know has raised the coils in a similar way to your idea, but just used a thick O ring between the existing one and the widest part of each coil. Then, to prevent any possibility of the seat pan touching any terminals, he has fitted a plastic sheet over all the electrics under the seat, the sheet is ziptied to the frame beside the tank; when he wants access to the electrics, he just rolls the plastic sheet up to the tank. Another use for some of the neoprene in your "Touring" thread?

On the plug wires... for some reason I seem to remember a more comprehensive way to test plug wires.

Any plug wires I need testing, I have a friend who is an engineer for the local power company ...

the side stand issue...
View attachment 59217
marked up
where I would add gussets

Unfortunately, certainly the gusset at the rear of the lug (top of your photo) would prevent the stand being retracted.

You might be able to add the gusset at the front of the lug (bottom of your photo) as drawn; however, checking the sidestand on my T160, the top of the stand (when extended) is flush with front of the lug when retracted. It might be you have to weld any extra gusset to the front of the lug and the frame tube?

In the early 1980s, Les Williams and Martin Russell strengthened the sidestand lug on T160s Les converted to his Legends (NVT used the same standard sidestand lug on triples, T160s weighed at least 70 lbs more than a twin ... ). LP Williams certainly used to stock the modified lug; sadly, Martin passed last year so could be why LPW do not list it now? Nevertheless, email LPW for more information, images?

wall thickness; just some mention that the frame tube used for OIF bike frames was Renolds 531.

Whoever mentioned that, can I have some of what he is smoking? Reynolds 531 was much too expensive for mass produced road bike frames.

Also, 531 could not be welded. BSA at Small Heath had been welding frames in the 1960s while Meriden was still pinning and brazing lengths of steel tube in separate cast lugs; one OIF requirement was they were to be welded. If you can study the remains of the original sidestand lug on the frame, can you tell if it was welded or brazed?

 

[NM Bonny]

On the frame repair: Looks like indeed LP Williams only lists no. 83-0035 (no stock). I've sent them an email, but anticipating you're right and they no longer sock modified ones--and since KM Jones has one in stock for far less than it'd cost me in time and raw steel to fabricate one--I'm ordering one from Kyle.

I had the same concern about the aft gussets, but need to have the assembly in hand to fiddle around with it and see what arrangement will work best. Regardless, I intend to bolster the piece to cure its design weakness--and add whatever other improvements I can fit in there.

Unfortunately, it's going to be difficult while the engine's in the bike to remove the old metal and yucky welding wire that the broker slathered in there, and to do a good job welding all the way around the new part.

On the ignition: I've double-checked the BB wiring, and indeed I've got it arranged as you indicate. I need to make sure it's sparking at the right time per each cylinder (yesterday, I only looked to see if I was getting a white (not yellow) spark on each side--but didn't think to make sure it was occurring at the right point per the BB setup, which I've confirmed is correct.

I was going to see if I could figure out a way to stabilize the bike on the lift to resolve the starting issue, but at this point don't want to do that because if I get it started, I'll be right back to not being able to ride it pending the frame repair. It's looking increasingly like I'll miss the 2024 riding season--and may have to R&R the engine. If I have to do that, I may (or may not) correct the center stand issue, too.

 

[Rudie]

looking increasingly like I'll miss the 2024 riding season

Commiserations, very frustrating when so close.

may have to R&R the engine. If I have to do that, I may (or may not) correct the center stand issue

Given the opportunity to fix any issue with the centrestand, I cannot imagine owning a bike without one. Friend of mine visited with his modern Triumph, needed to lube the chain before he left the following morning - two grown men, expensive bike balanced on sidestand and front wheel, what could possibly go wrong ... For the sake of a bit of curved tube bolted under the bike? I asked him what he would do if the bike had a rear wheel puncture, he replied he had not had one yet ...

 

[NM Bonny]

Commiserations, very frustrating when so close.


Given the opportunity to fix any issue with the centrestand, I cannot imagine owning a bike without one. Friend of mine visited with his modern Triumph, needed to lube the chain before he left the following morning - two grown men, expensive bike balanced on sidestand and front wheel, what could possibly go wrong ... For the sake of a bit of curved tube bolted under the bike? I asked him what he would do if the bike had a rear wheel puncture, he replied he had not had one yet ...

Thanks for the sympathy. I was pretty blue this morning, I must say...

Yeah, if I have to R&R the engine, I may well do that. I think that I saw a tutorial somewhere when was looking into buying an OIF bike that showed how to realign and reinforce the tabs that receive the center stand pivot...

That said, with my DIY jack adapter, it's on the stand in literally 60 seconds for chain lubing and adjustments, etc. Same jack works for the '51 FL w/o an adapter. But for over-the-road stuff, I agree that it'd be nice to have a center stand.

Now that I know the wiring is copasetic, I'm going to drop the float bowls and see if by some strange chance both needle valves are stuck closed. That seems unlikely but would certainly explain an engine firing upon tickling but then not running, eh?

 

[CarlS]

Thanks for the sympathy. I was pretty blue this morning, I must say...

Yeah, if I have to R&R the engine, I may well do that. I think that I saw a tutorial somewhere when was looking into buying an OIF bike that showed how to realign and reinforce the tabs that receive the center stand pivot...

That said, with my DIY jack adapter, it's on the stand in literally 60 seconds for chain lubing and adjustments, etc. Same jack works for the '51 FL w/o an adapter. But for over-the-road stuff, I agree that it'd be nice to have a center stand.

Now that I know the wiring is copasetic, I'm going to drop the float bowls and see if by some strange chance both needle valves are stuck closed. That seems unlikely but would certainly explain an engine firing upon tickling but then not running, eh?

Let us know what you find. I know this is very frustrating.

 

[NM Bonny]

Well, as the kids like to say, OMG!!!

I double-checked everything, from the float levels to the jets for obstructions, to the ignition coils (both primary and secondary windings within spec), to the BB stator coils (within spec)...

...and then I checked to see if the connections to the BB box were tight (see photo).

As you can see, I had carefully redone all the connections, even putting a dab of solder on the connectors after crimping the leads, and then shrink-wrapping them. These should last a very long time without issues. I even put a nice piece of high quality foam underneath the BB box to protect it from vibrations. The whole nine yards.

And then I saw it. Yes! I had plugged the white wire into the yellow connector and vice-versa! Of all the...

So, plugged the #@$% plugs into the right *&%# receptacles, tickled the carbs, and... the engine fired on the second kick. Just like a '70s Bonny should.

I am sure it was just tired eyes working in the garage late at night whenever I finished up the wiring that resulted in the Homer Simpson wiring maneuver. But I am thrilled it was a harmless, dumb mistake and not something basic to the condition of the engine.

Speaking of the engine:

• very responsive and tight-sounding (though I'll reserve judgment until the first ride)
• veritable geyser of oil from the scavenge pump into the tank (I had installed new check valves and springs, checked operation per the manual, and primed it before resintallation)
• not a single oil leak that I can see after running it for a few minutes (remarkable, but here again, let's see what happens after an hour on the road)
• tach works great

I topped up the oil after running for a minute or two. I then drilled holes through my DIY jack adapter into the floor motorcycle jack to receive drop-in pins, as she wanted to vibrate backward off the stand (maybe because of the direction of rotation?).

Since I have to repair the side stand before riding anyway, I'm going to go ahead and repack the Dunstall replicas with that special expanding UK packing I bought. She's a bit loud!

Though to be fair I have yet to set the idle screws, so she was sitting at 3,500~4,000 rpms in the garage. Idling should be significantly quieter, I would think, even with the woefully inadequate packing the mufflers come with...

 

[CarlS]

Congratulations!!!

 

[sikatri]

Absolutely fabulous! Look forward to the maiden voyage sort of when the last bits are fixed.

 

[NM Bonny]

Thanks, guys! Really, very excited to ride this custom cafe creation of mine for the first time after more than a year's work. Hope the tranny shifts well...

I'm making a checklist of pre-ride items (aside from repairing side stand forever). Goes something like this--but please weigh in if I've forgotten something:

• set idle, finalize mixture screws & double check carb slide synchronization (set this earlier in build)
• set dynamic timing
• check alternator output (battery's great)
• final oil level check
• aim headlamp (LED brake & tail light work great)
• tighten axle, fairing, handlebar, foot peg & exhaust fasteners
• check tire pressure & lube chain
• firmly tap spoke nipples @ hubs with drift & tighten any loose spokes
• finalize tool roll components (quite limited space under seat - need to sew cotton duck roll with wrench pockets)
• ...and...?

 

[NM Bonny]

I installed pins to hold the jack adapter steady while running the bike (pending the side stand repair) and set about adjusting the carburetors. The bike starts consistently and easily with strong, regular pulses at both mufflers. (A little quieter with new packing per the other thread.)

However, it acts like it has an intake manifold leak: idling far too high and not responding well to mixture screw adjustments.

I sprayed a little WD40 on the carb-to-manifold joints and got a very slight stumble when spraying the L/H side... which corresponds to the L/H pipe starting to turn color before the R/H pipe, and sure enough my optical thermometer says L/H is running 35~40F hotter as the engine heated up.

I tightened the big manifold-to-head locking nuts, as one had vibrated itself loose (and realized I need to make up a thin spanner to go in the tool kit) and also the carb-to-manifold nuts, but to no avail. Are there sealing tips for the big locking nuts?

Then I remembered Rudie (?) mentioning switching over to the fatter 70-9711 carb-to-manifold O-rings. With all the tasks I've had, didn't remember to do that. I assume these are better than the flat, regular gaskets included in the top end kit?

With the manifold balance tube an air leak on the L/H side would be communicated to both sides, if its effect manifesting slightly less on the R/H. So, mañana after she cools off, I'll install the thicker O-rings and see if that solves the idle adjustment issue--and of course head off burning an exhaust valve.

Do people add grease to these O-rings to help them seal?

Also: a guy's post on another forum says: "Do NOT overtighten the flange nuts! I use feeler gauges and my carb sits proud of the manifold by about .045". You should be able to gently rock the carb back and forth on the O-ring with your hand."

Sound good?

Finally: I am tempted to plug the balance tube nipples, eliminate another potential source of leaks, and have two, truly separate cylinders. After all, these carbs are extremely easy to balance. Any down sides?