Sounds just like me
Careful, I might adjust my first over-the-road trip to show up and mooch a glass...
Restoring & Modifying 1971 OIF TR120
- Thread starter NM Bonny
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Careful, I might adjust my first over-the-road trip to show up and mooch a glass...
L-o-n-g day... but worth it. This was the least damaged part I've sanded and pollished on this bike, yet it had lots of surface area. Still had to start at 220 dry to get out the deeper scratches. Anyway, it was worth doing, even if it meant no workout this afternoon, as my hands are so tired I'd have dropped a dumbbell on my head...
Tomorrow, I get to button up the primary and add oil--which for the first time won't just run back out again!
The circlips came for the safety mod to the front axle. Wow... I am going to need to register and insure this bike pretty soon!
Tomorrow, I get to button up the primary and add oil--which for the first time won't just run back out again!
The circlips came for the safety mod to the front axle. Wow... I am going to need to register and insure this bike pretty soon!
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That looks amazing, great job. I bought a bench mounted buffer to do those kind of jobs. Easier on the hands.
Thanks very much!
BTW, I've got a bench-mounted Eastwood buffer. It's the several hours of sanding one must do to remove the deep scratches, nicks, and gouges before stepping over to the buffer that are so hard on the fingers. Buffing compound won't take out that stuff, unfortunately...
I've removed marks up to 1/16" deep from some of these bits!
Okay, final modification-related task done! I took the HTF axle down the block to the machinist, and he had bought the hardest cutters he could find to sink the snap ring groove into the Rockwell 60 (!!!) bearing shaft.
As you can see, the cutter lasted precisely two grooves before exploding! Ah, well... the kit I plan to offer will likely include a 4140 alloy steel axle which will be more than adequate and not destroy incredibly expensive cutters!
Anyway, installation took barely 10 minutes w/zero drama (see my other thread about a DIY motorcycle jack adapter for OIF bikes), and now I have 100% peace of mind re: the axle staying put, as the stainless circlips are rated at 3,750 lbs shear strength--and they're not nearly as hard as the axle into which they insert!
The kit, if I offer one, would include:
1) machined 4140 steel axle with stainless circlips;
2) machined 6061 aluminum caliper adapter;
3) machined 6061 aluminum one-piece bearing/hub spacers;
...and for 73 and later bikes...
4) machined 6061 aluminum rotor spacer;
...and for those who want dual discs...
5) 2x items 2 and 4.
Off-the-shelf or used components DIYers would need:
- 73-and-later Triumph disc brake sliders (only L/H is critical but aesthetically both are desirable);
- built 2000 Harley sportster wheel 19" (available on various websites like Dennis Kirk, eBay, et al.);
- 11.5" Harley-spec (thin band) rotor - you can use standard-width band rotors but the Willwood's pads won't use the full width of the bedding surface;
- Willwood 4-pot aluminum caliper;
- Goodrich braided steel bolt-on brake line and banjo fittings;
- $22 aluminum master cylinder I found which aesthetically is very close to OEM '70s Triumph levers;
...and for those who want dual discs...
- R/H late-model disc brake slider (TBS has them but they're obscenely expensive new from LF Harris - better to hunt down used one)
- 2x rotors (new built sporty wheels generally come with double sided hubs; mine is an OEM hub I got used on eBay that is single-sided)
- 2x caliper adapters (I have already had my machinist 'mirror image' the design in his CAD program).
And the master? As it turns out, a smaller master vis-a-vis slave cylinder(s) means less lever force needed but more travel. Here, the travel is so short with one 4-pot caliper that one should actually get improved micro-modulation with twin discs, which matters more for racers, people like Speedrattle who routinely exceed 100 mph, than us mere mortals. Obviously, were people interested in twin 11.5" discs, I'd assemble the setup and try it out before offering it...
Anyway, I'll soon be trying this new DIY setup on the road, and will post a video with some rider impressions!
As you can see, the cutter lasted precisely two grooves before exploding! Ah, well... the kit I plan to offer will likely include a 4140 alloy steel axle which will be more than adequate and not destroy incredibly expensive cutters!
Anyway, installation took barely 10 minutes w/zero drama (see my other thread about a DIY motorcycle jack adapter for OIF bikes), and now I have 100% peace of mind re: the axle staying put, as the stainless circlips are rated at 3,750 lbs shear strength--and they're not nearly as hard as the axle into which they insert!
The kit, if I offer one, would include:
1) machined 4140 steel axle with stainless circlips;
2) machined 6061 aluminum caliper adapter;
3) machined 6061 aluminum one-piece bearing/hub spacers;
...and for 73 and later bikes...
4) machined 6061 aluminum rotor spacer;
...and for those who want dual discs...
5) 2x items 2 and 4.
Off-the-shelf or used components DIYers would need:
- 73-and-later Triumph disc brake sliders (only L/H is critical but aesthetically both are desirable);
- built 2000 Harley sportster wheel 19" (available on various websites like Dennis Kirk, eBay, et al.);
- 11.5" Harley-spec (thin band) rotor - you can use standard-width band rotors but the Willwood's pads won't use the full width of the bedding surface;
- Willwood 4-pot aluminum caliper;
- Goodrich braided steel bolt-on brake line and banjo fittings;
- $22 aluminum master cylinder I found which aesthetically is very close to OEM '70s Triumph levers;
...and for those who want dual discs...
- R/H late-model disc brake slider (TBS has them but they're obscenely expensive new from LF Harris - better to hunt down used one)
- 2x rotors (new built sporty wheels generally come with double sided hubs; mine is an OEM hub I got used on eBay that is single-sided)
- 2x caliper adapters (I have already had my machinist 'mirror image' the design in his CAD program).
And the master? As it turns out, a smaller master vis-a-vis slave cylinder(s) means less lever force needed but more travel. Here, the travel is so short with one 4-pot caliper that one should actually get improved micro-modulation with twin discs, which matters more for racers, people like Speedrattle who routinely exceed 100 mph, than us mere mortals. Obviously, were people interested in twin 11.5" discs, I'd assemble the setup and try it out before offering it...
Anyway, I'll soon be trying this new DIY setup on the road, and will post a video with some rider impressions!
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Got the oil tank and primary oiled up (no leaks!) and the valves adjusted, and I was right: the early models with the threaded manifolds are easy-peasy, as shown. As you can see, just loosen the locking nut and balancing hose, and voila: the carbs pivot out of the way. No disturbing the O-ring between carb and manifold.
Also, I just bent up my .002" feeler, as the old bent set doesn't go that low... both will go in the tool kit for adjustments on long trips.
Finally, I almost bought that fancy adjuster tool the usual suspects sell, but am glad I didn't: it's easy to adjust these valves, so long as you use a small, ignition wrench-sized open end for the square adjuster. (They were all too tight and some gorilla overtightened the adjuster lock nuts...)
Reinstalling the Boyer Bransden electronic ignition was simple, too--but one question:
I could've sworn I saw a video where the mark(s) on the alternator rotor were TDC, and you need to make a paint mark 38 degree before the mark--which I did (easily removed if need be).
However, the manual indicates that the mark on the rotor corresponds to 38 BTDC--and in my case, as you can see, there are two marks on the rotor.
It's a pain for me to figure this out because I cannot get my socket fully over the flats on the plug that otherwise would let me insert my timing device to find the TDC and 38 BTDC holes in the crank.
So: is the rotor mark TDC or 38 BTDC as the manual says? In either case, what's the deal with two marks?
Also, I just bent up my .002" feeler, as the old bent set doesn't go that low... both will go in the tool kit for adjustments on long trips.
Finally, I almost bought that fancy adjuster tool the usual suspects sell, but am glad I didn't: it's easy to adjust these valves, so long as you use a small, ignition wrench-sized open end for the square adjuster. (They were all too tight and some gorilla overtightened the adjuster lock nuts...)
Reinstalling the Boyer Bransden electronic ignition was simple, too--but one question:
I could've sworn I saw a video where the mark(s) on the alternator rotor were TDC, and you need to make a paint mark 38 degree before the mark--which I did (easily removed if need be).
However, the manual indicates that the mark on the rotor corresponds to 38 BTDC--and in my case, as you can see, there are two marks on the rotor.
It's a pain for me to figure this out because I cannot get my socket fully over the flats on the plug that otherwise would let me insert my timing device to find the TDC and 38 BTDC holes in the crank.
So: is the rotor mark TDC or 38 BTDC as the manual says? In either case, what's the deal with two marks?
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Great progress.
So, here is Lunmad's video (rest his soul) on timing marks. At 4:32 into the video, he mentions alternator rotors like mine, and indicates that in his experience, the rotors with two little rectangles each containing a hash mark, one of them is TDC and not 38 BTDC.
Therefore, I had marked my rotor as you see in the above post, just as Lunmad marked his.
I had forgotten this afternoon when I posted above that a 5/8" spark plug socket is thin-walled. Sure enough, I just succeeded in removing the timing plug and can now insert my tool to engage the timing holes in the crank.
I believe that will let me confirm which is the case with the Lucas rotors they're selling these days that have twin marks--but it's too dark out in the garage. So, it'll have to be mañana...
Therefore, I had marked my rotor as you see in the above post, just as Lunmad marked his.
I had forgotten this afternoon when I posted above that a 5/8" spark plug socket is thin-walled. Sure enough, I just succeeded in removing the timing plug and can now insert my tool to engage the timing holes in the crank.
I believe that will let me confirm which is the case with the Lucas rotors they're selling these days that have twin marks--but it's too dark out in the garage. So, it'll have to be mañana...
About 38 degrees BTDC. If you want absolute accuracy, it is as well to verify with the factory tool that picks up on divots in the flywheel.
Lucas alternator rotors with two marks 180 degrees apart were first made for the 71 model year; Triumph and BSA had intended to introduce a new range of 350 cc parallel twins (Triumph Bandit, BSA Fury) with 180 degree cranks. The entire project was subsequently abandoned during 1971 due to the BSA Group's worsening financial situation and development difficulties with the completely new engine.
Then, for 76, Triumph fitted the 750 twins with a new primary chaincase, that replaced the separate cover over the alternator rotor and the fixed timing pointer in about the five o'clock position, with a smaller plug in the chaincase 180 degrees from the previous timing pointer position. However, obviously there was/is no control over whether a new rotor was/is fitted to a 76 on or pre-76 bike, so rotors had/have two marks 180 degrees apart.
Afaict the rotor in the video is not standard for a twin: its part number has only seven figures and begins with a "4"(?); 71 650 parts book lists 54213901, that Lucas part number is listed in all 62 on singles and twins parts books, when Lucas first supplied 74 mm o.d. rotors and matching stators.
About 38 degrees BTDC. If you want absolute accuracy, it is as well to verify with the factory tool that picks up on divots in the flywheel.
Lucas alternator rotors with two marks 180 degrees apart were first made for the 71 model year; Triumph and BSA had intended to introduce a new range of 350 cc parallel twins (Triumph Bandit, BSA Fury) with 180 degree cranks. The entire project was subsequently abandoned during 1971 due to the BSA Group's worsening financial situation and development difficulties with the completely new engine.
Then, for 76, Triumph fitted the 750 twins with a new primary chaincase, that replaced the separate cover over the alternator rotor and the fixed timing pointer in about the five o'clock position, with a smaller plug in the chaincase 180 degrees from the previous timing pointer position. However, obviously there was/is no control over whether a new rotor was/is fitted to a 76 on or pre-76 bike, so rotors had/have two marks 180 degrees apart.
Afaict the rotor in the video is not standard for a twin: its part number has only seven figures and begins with a "4"(?); 71 650 parts book lists 54213901, that Lucas part number is listed in all 62 on singles and twins parts books, when Lucas first supplied 74 mm o.d. rotors and matching stators.
Fascinating history, as usual - thank you for taking the time, Rudie. Too bad we never got a 180 degree-crank twin!
Indeed, I noticed the differing part numbers when ordering but both TBS and KM Jones (the OIF parts house) offer just one Lucas rotor--with the twin marks 180 degrees apart (KM Jones is far cheaper for the same part). KM Jones also offers an Emgo part for $120, but I went with a Lucas rotor, perhaps stupidly...
It wouldn't surprise me that Lunmad used an odd rotor; he wasn't a rich man and as revealed in his videos most often made do with whatever he could get his hands on.
Okay: as I was able to remove the plug, I will use the timing tool to discover what crank position the rotor's marks coincide with and report back later today.
Yup, going by the divots in the crank, looks like the rotor mark is right on 38 BTDC, per first photo (I made a 'T' for TDC to facilitate valve accurate adjustments). I set the BB ignition per its instructions, which use the 38 BTDC 'full advance' mark for initial timing.
As for initial oil level, I added proportionately the same amount above the primary chain case 'prime' amount called for in the '71 T120R manual, as the author of 'Waking the Sleeping Beast' suggests exceeding the corresponding prime amount for triples.
I did this slowly, and each time I poured--for a little while, anyway--the level eased down as the oil seeped back into the crankcase through the three teensy holes. I stopped when this equalization process stopped (I think this was on the side stand). You can't see it in the timing marks photo, but I ended up with oil immersing the bottom of the stator with the bike on its side stand.
Question: should I add a touch into the crankcase via the timing plug, even though the author of "Sleeping Beast" doesn't do that?
As the next two photos show, here is the oil level with 1-1/2 qts poured into the integral oil tank (dipstick is roughly where it would sit inside the tube: the bottom tab has the 'add' mark). Frankly, I'm a little uneasy with having it that low for startup, but this seems to be the usual practice to avoid the tank overflowing...?
Anyway, everything else is ready to go: valves adjusted, petcocks sealed up to the tank, fuel lines attached, intake and exhaust fasteners tightened... I hope to have time tomorrow or over the weekend to go grab some gas, oil the valve train per 'Waking the Sleeping Beast,' and give her a go!
I think there may be suggested initial settings in the Amal literature The tuning guide merely discusses what role the low-speed/idle mixture screws play--but not where to start out, re: [x] turns from seated.
We'll see what happens...
As for initial oil level, I added proportionately the same amount above the primary chain case 'prime' amount called for in the '71 T120R manual, as the author of 'Waking the Sleeping Beast' suggests exceeding the corresponding prime amount for triples.
I did this slowly, and each time I poured--for a little while, anyway--the level eased down as the oil seeped back into the crankcase through the three teensy holes. I stopped when this equalization process stopped (I think this was on the side stand). You can't see it in the timing marks photo, but I ended up with oil immersing the bottom of the stator with the bike on its side stand.
Question: should I add a touch into the crankcase via the timing plug, even though the author of "Sleeping Beast" doesn't do that?
As the next two photos show, here is the oil level with 1-1/2 qts poured into the integral oil tank (dipstick is roughly where it would sit inside the tube: the bottom tab has the 'add' mark). Frankly, I'm a little uneasy with having it that low for startup, but this seems to be the usual practice to avoid the tank overflowing...?
Anyway, everything else is ready to go: valves adjusted, petcocks sealed up to the tank, fuel lines attached, intake and exhaust fasteners tightened... I hope to have time tomorrow or over the weekend to go grab some gas, oil the valve train per 'Waking the Sleeping Beast,' and give her a go!
I think there may be suggested initial settings in the Amal literature The tuning guide merely discusses what role the low-speed/idle mixture screws play--but not where to start out, re: [x] turns from seated.
We'll see what happens...
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Absolutely fabulous!
You are amazing!
I certainly don't feel that way, but thank you for the kindness, just the same. I see that it's been just over a year since I started this thread!
Even though I've been turning wrenches since 1974 (first motorbike was powered by a rusted lawnmower engine I bought in a cardboard box and rebuilt with the help of the neighborhood mechanic while he watched football playoffs), and this weekend's event should be... well, uneventful, there's still a feeling of suspense. "Will the darned thing actually run...?"
As I fall asleep tonight instead of sheep it'll be a final to-do list spooling before my mind's eye: buy insurance, get gasoline, charge up GoPro, lube chain, check wheel & suspension fasteners...
I would be surprised if they are not the same part, Emgo and Wassell ("Lucas") co-operate on parts sourced in the Far East.
Also certainly Wassell calls it the "RM20" rotor. RM20 was another 3-wire single-phase stator, more powerful than the RM19 standard between 62 and 68; I believe the RM20 was supplied on bikes for the police? RM20 produced about the same Amps as the RM21, RM20 were fitted to 69 triples when the RM21 was fitted to twins (possibly BSA did a deal with contemporary Lucas to use up the last RM20 as BSA planned to build only a few thousand 69 triples?).
My understanding has always been the RM20 rotor was wider than the RM21; however, I have not had two originals side by side. No difficulties fitting a Wassell "RM20" rotor in a twin posted in any of the forums.
"Waking The Sleeping Beast" was written for triple owners, triple timing plug is in a completely different place from a twin's (about half way down the front of the timing side crankcase).
Fwiw, agree with your "initial oil level, I added proportionately the same amount above the primary chain case 'prime' amount called for in the '71 T120R manual ... I stopped when this equalization process stopped ... ended up with oil immersing the bottom of the stator with the bike on its side stand", except I would do it with bike on the centrestand, or at least propped vertical.
I would be surprised if they are not the same part, Emgo and Wassell ("Lucas") co-operate on parts sourced in the Far East.
Also certainly Wassell calls it the "RM20" rotor. RM20 was another 3-wire single-phase stator, more powerful than the RM19 standard between 62 and 68; I believe the RM20 was supplied on bikes for the police? RM20 produced about the same Amps as the RM21, RM20 were fitted to 69 triples when the RM21 was fitted to twins (possibly BSA did a deal with contemporary Lucas to use up the last RM20 as BSA planned to build only a few thousand 69 triples?).
My understanding has always been the RM20 rotor was wider than the RM21; however, I have not had two originals side by side. No difficulties fitting a Wassell "RM20" rotor in a twin posted in any of the forums.
"Waking The Sleeping Beast" was written for triple owners, triple timing plug is in a completely different place from a twin's (about half way down the front of the timing side crankcase).
Fwiw, agree with your "initial oil level, I added proportionately the same amount above the primary chain case 'prime' amount called for in the '71 T120R manual ... I stopped when this equalization process stopped ... ended up with oil immersing the bottom of the stator with the bike on its side stand", except I would do it with bike on the centrestand, or at least propped vertical.
Ah, well... wasted a few bucks on a green Lucas box. Okay, in the future I'll buy the Emgo rotor.
Yes, I realized the "Sleeping Beast" article was for triples. I just couldn't find an equivalent article for Unit 650s, so figured extrapolation from that was the next best thing--and it seems fairly well reasoned.
I think that I may experiment with dribbling a little oil into the crankcase via the timing plug hole, watching the level in the primary chain case to avoid it overflowing during dynamic timing. I just really want a bit in the crankcase to facilitate splash lubrication in the first few instants after the engine fires.
I really like his suggestion of pressurizing the external rocker oil feed to wet the rocker shafts inside.
Off to 'the big city' to run errands, which happily will include registering the bike and getting some premium gasoline!
Most of it should be gone once the engine's been run, the extra oil in the crankcase and chaincase has been scavenged into the frame. Although, as you have noticed, excess in the chaincase does not drain very quickly into the crankcase.
Even when the primary oil is down to a 'normal' level, as the bottom run of the chain drags in it, expect a fine spray out of the chaincase when it is open for timing ...
Round bit of perspex or similar to fill the hole in the primary during timing?
Most of it should be gone once the engine's been run, the extra oil in the crankcase and chaincase has been scavenged into the frame. Although, as you have noticed, excess in the chaincase does not drain very quickly into the crankcase.
Even when the primary oil is down to a 'normal' level, as the bottom run of the chain drags in it, expect a fine spray out of the chaincase when it is open for timing ...
Okay, thanks.
I used to have some leftover acrylic, so if I can find it I'll try that. If not, just have to put a pan under the exposed rotor. Not sure how to avoid that otherwise...
Well... no dice.
All went well (no fuel leaks, lubed up the valve train and squired a bit into the crankcase) but although the bike fired one or twice, and there seemed to be a minor backfire, she wouldn't run.
I believe it has sufficient compression to fire at 140 psi in both cylinders dry/cold (within 1 psi of each other) per my first post in this thread.
I worried that I might have timed the BB ignition to no. 2 cylinder, but confirmed by watching the intake valve open and close as no. 1 piston rose to TDC, then observed the BB alignment and timing marks I'd made with the divots in the crankcase (again). See 1st and 2nd pics.
I 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.
So, figured I'd flooded the cylinders. Let the cylinders air out a bit while I mounted the license plate, tried again... and the kick stand's ugly welding job that the broker did busted. Down we went.
Next two pics show the awful welding job he had done.
Remarkably, as the final shot shows, I could not find a scratch anywhere on the bike. Muffler and pipe--perfect. Paint and fairing--perfect. Fork slider--perfect.
It seems to have rested solely on the folding foot peg and mirror, which only sustained a bent screw--and I have several as they came in a little 10-pack. So, that was fixed in two minutes.
The L/H clip-on merely rotated around the fork tube a few degrees, so that took another two minutes to resolve.
So, my latest questions:
1) is there an OIF-specific clamp-on kickstand anyone is aware of? I'm competent to weld heavier stuff but do not have a TIG and don't want to chance melting the tubes on an OEM vintage frame.
2) on the starting issue...
I believe looking at the first photo that I used the clockwise timing hole, and as you face the alternator rotor, the engine's turning counter-clockwise. But from the ignition side, the engine turns clockwise.
Which is right? Does BB's reference to clockwise vs. counterclockwise mean as viewed from the ignition side or from the alternator side?
All went well (no fuel leaks, lubed up the valve train and squired a bit into the crankcase) but although the bike fired one or twice, and there seemed to be a minor backfire, she wouldn't run.
I believe it has sufficient compression to fire at 140 psi in both cylinders dry/cold (within 1 psi of each other) per my first post in this thread.
I worried that I might have timed the BB ignition to no. 2 cylinder, but confirmed by watching the intake valve open and close as no. 1 piston rose to TDC, then observed the BB alignment and timing marks I'd made with the divots in the crankcase (again). See 1st and 2nd pics.
I 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.
So, figured I'd flooded the cylinders. Let the cylinders air out a bit while I mounted the license plate, tried again... and the kick stand's ugly welding job that the broker did busted. Down we went.
Next two pics show the awful welding job he had done.
Remarkably, as the final shot shows, I could not find a scratch anywhere on the bike. Muffler and pipe--perfect. Paint and fairing--perfect. Fork slider--perfect.
It seems to have rested solely on the folding foot peg and mirror, which only sustained a bent screw--and I have several as they came in a little 10-pack. So, that was fixed in two minutes.
The L/H clip-on merely rotated around the fork tube a few degrees, so that took another two minutes to resolve.
So, my latest questions:
1) is there an OIF-specific clamp-on kickstand anyone is aware of? I'm competent to weld heavier stuff but do not have a TIG and don't want to chance melting the tubes on an OEM vintage frame.
2) on the starting issue...
I believe looking at the first photo that I used the clockwise timing hole, and as you face the alternator rotor, the engine's turning counter-clockwise. But from the ignition side, the engine turns clockwise.
Which is right? Does BB's reference to clockwise vs. counterclockwise mean as viewed from the ignition side or from the alternator side?
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No... I appear to have done it right. It says camshaft rotating clockwise...
So, I'll have to check the coils against the specs in the manual. Perhaps one or both is faulty--though their total resistance is sufficient per the instructions. I'm guessing (though I don't know) the PO had installed two 6v coils...
Here is what BB says:
"For low compression engines, two 12 volt coils (4 Ohm Resistance) in series are satisfactory, but for racing and high compression engines two 6 volt coils (2 Ohm resistance) in series, or one 12 volt 3.5 ohm or more primary winding resistance dual output coil will give the best results."
So, I'll have to check the coils against the specs in the manual. Perhaps one or both is faulty--though their total resistance is sufficient per the instructions. I'm guessing (though I don't know) the PO had installed two 6v coils...
Here is what BB says:
"For low compression engines, two 12 volt coils (4 Ohm Resistance) in series are satisfactory, but for racing and high compression engines two 6 volt coils (2 Ohm resistance) in series, or one 12 volt 3.5 ohm or more primary winding resistance dual output coil will give the best results."
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