CB360G yard find — ongoing project log

I replaced my clutch springs in 2017. I looked through my eBay purchase history this morning and found that they were EBC springs, advertised as 10% stiffer than stock. I imagine heavier springs could make it easier for the plates to get stuck together and, since this is not a high torque motor, stock springs should be fine.

I saved the original springs and measured them yesterday. Their free lengths were no less than 31.5mm, whereas the FSM lists 31.25mm as the standard value with a service limit of 29.7mm. They all have a bit of red paint on them very similar to this photo from an NPN listing.



Does the red paint indicate anything special, i.e., could it explain why the springs are longer than the standard value? I would assume that longer springs will be heavier and, at this point, I don't think I want or need heavier springs.
Heavier springs have a thicker wire gauge on all the ones I've seen.
 
Heavier springs have a thicker wire gauge on all the ones I've seen.
Thanks. I'll compare the red ones with those by EBC. In the case of equal wire diameter, free length would determine preload when installed and longer springs would could end up being heavier.

I really wonder why there is paint on half of the springs like that. It almost seems like it would be for quality control or some other production concern.
 
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A spring can be considered as a wound torsion bar, think about it ;)
Yes — this makes sense, but I'm still at a loss for explaining the red paint.

Edit: I think I now see the point you are steering me towards. With the same diameter wire, the longer spring has a smaller spring rate (softer) since its strain for any given displacement is smaller. So this creates a trade-off with the difference in preload, I guess.
 
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Thanks. I'll compare the red ones with those by EBC. In the case of equal wire diameter, free length would determine preload when installed and longer springs would end up being heavier.

I really wonder why there is paint on half of the springs like that. It almost seems like it would be for quality control or some other production concern.
Very true. The paint may be a batch identifier. Wire gauge, metalurgy or even heat treating could cause variances. FIAT used paint for different suspension coil batches.
 
I have a Pamco unit on the 350 from Outobie (John Knox) that I know little about, other than I can see the original advancer base under it. The bike needs other work before I get it running but hope you can answer any questions that come up. I'd like to keep it and take good care of it so, if you've any suggestions, let me know.
I'll try my best. I have the schematic and instructions:
 

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I received the reversible countersink tool today. I think PJ's countersink method using a 1/4" ball burr and die grinder is probably better, but I was able to put a chamfer on the holes in the inner clutch hub. The blade in the tool can be replaced, if I can still find a replacement and a super tiny hex wrench whenever this one wears out.

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Regarding the red paint in one side of the original clutch springs, I found one thread on caferacer.net where someone mentions that they had encountered the red painted springs and found them to be heavier than those found without the paint.

I've also seen that in some scooter applications, clutch springs are color coded based on the speed in which they engage (centrifugal clutch, I guess).

I ordered a set of Honda springs and I'm planning to compare the three sets to see if anything definitive can be said.
 
Beautiful bevel Brody. You do find some interesting things.
Thank you, Tom. When I saw PJ's example the first thing that stood out was that I had no idea how to put a bevel on an inside hole. I had seen deburring tools, but didn't think they could get the right angle. I forget how many searches it took, but eventually that thing popped out.

I probably shouldn't disclose this fact, but you should know that, whenever possible, I'm going to choose the best of the bunch when posting photos. Some of the other holes were closer to the adjacent vane, which made it harder to get a clean and even chamfer.
 
Thank you, Tom. When I saw PJ's example the first thing that stood out was that I had no idea how to put a bevel on an inside hole. I had seen deburring tools, but didn't think they could get the right angle. I forget how many searches it took, but eventually that thing popped out.

I probably shouldn't disclose this fact, but you should know that, whenever possible, I'm going to choose the best of the bunch when posting photos. Some of the other holes were closer to the adjacent vane, which made it harder to get a clean and even chamfer.
Mamas don't post the ugly baby shots either, that said, I still enjoy the mistakes and learning curves.
 
There are sometimes debates about the relative merits of the CB350 and CB360 twins. I'm partial to the CB360, since it is the first motorcycle I did any significant work on, but I feel like the CB350 is the popular choice. One small point in the favor of the CB360 is that, by design, it includes a retainer for the clutch rod oil seal.

Rqe7ego.jpg


Don't mind the mess — I still need to clean in there!
 
There are sometimes debates about the relative merits of the CB350 and CB360 twins. I'm partial to the CB360, since it is the first motorcycle I did any significant work on, but I feel like the CB350 is the popular choice. One small point in the favor of the CB360 is that, by design, it includes a retainer for the clutch rod oil seal.

Rqe7ego.jpg


Don't mind the mess — I still need to clean in there!
While you are correct, it only means the seal only pushed out on the bottom ;) I never had the seal come out, FWIW
 
I like the 360 because it's a true 360cc engine while the 350 is 325cc. Plus, it has a nice 6-spd trans.
I think CrazyPJ has some wise words on top end oiling - he's our resident go-to guy for this bike.

But I'm stuck with these crazy 450's!
 
I like the 360 because it's a true 360cc engine while the 350 is 325cc. Plus, it has a nice 6-spd trans.
I think CrazyPJ has some wise words on top end oiling - he's our resident go-to guy for this bike.

But I'm stuck with these crazy 450's!
I enjoy all three of my current rides (CB360G, XL350k2, CB450k7), but, for whatever reason, I feel most comfortable on the 360.

I have a set of +0.5mm pistons waiting for a top end refresh, but if PJ continues to influence me I'll probably be running Suzuki pistons at some point in the future.

We're all glad that you're fixated on the 450's.
 
When I first rode my CB360, it was 2 years old, original owner only ran it one season. 700 Miles on it. It rode terrible. Wheel alignment, loose spokes, loose neck bearings...was a disappointment as my previous 1969 CB350 was better handling and faster.
While I corrected all the faults, it still wasn't as planted as the CB350. Fast forward to 2014. With lighter, wider wheels, careful truing, replacing a broken motor mount (replaced bottom engine half) and careful assembly, I was happily surprised at how much better it handled than before. Since previously, I had trued wheel, aligned, replaced swing arm bushings, had Honda dealer check everything, with no serious improvement. I think the largest single thing was the 1 size wider wheel on stock size tires. At any rate, the handling is now on par with my recollection of the 350, but the 350 was still faster. Since I became uh, more mature, I am adverse to pain so I am not so worried about being faster.

After years of not being sure if the bike would ever handle reasonably, I am happy that it can be made reasonable. If this was the only bike, I'd think it handled well, but my BMW handles well, so the contrast is evident. So the CB360 handles as well as it should now.

My CB750 was never a fantastic handler either. It wallows in the turns, never feels completely planted. BMW did spoil me on handling. All three bikes handle the way they should though.
 
When I first rode my CB360, it was 2 years old, original owner only ran it one season. 700 Miles on it. It rode terrible. Wheel alignment, loose spokes, loose neck bearings...was a disappointment as my previous 1969 CB350 was better handling and faster.
My 360 is a two-owner machine as well, but there was a dormancy period of 30+ years between the first owner parking it and him gifting it to me when I pushed it out of his yard. The first time I rode it, there was still water between the tubes and tires and it made a decent mess at the shop where I bought new tires and tubes. I haven't ridden many newer bikes, aside from delivering a smaller CBR for a friend and a short ride on a Triumph Thruxton that I actually won in a raffle. Those bikes had much better balance, but I didn't like the riding posture at all.

Given that the CB360's aren't the most popular vintage bikes out there, they are a good choice for those of us that like them. They can still be had at a reasonable price and some new members in the last couple of years managed to find really clean survivors. My only reason for choosing this bike was the fact that it was free and I could use it to learn without worrying about making it any worse. I'm glad I had that opportunity and took advantage of it, despite advice to the contrary from all of my immediate family members! I'm still very grateful to the original owner.
 
I had most of the afternoon to get back to work on the bike. The stuck clutch plates made a good excuse to refresh the bike in other ways and it took a little time to gather all of the parts. I ordered a new set of Honda clutch springs and received them today. I had already received the new rotor from Rick's Electrics and the starter block-off that @crazypj fabricated, so today was the day to put it all back together.

LyffbrC.jpg


Every motorcycle should have at least one shiny part and I have to thank PJ for putting a nice shine on the outer face of the plug. The plug is snug, but wasn't difficult to install. In contrast, the "commercial" one that I installed on my CB350 project was a little too tight and has a tendency to chew up the o-ring, so I expect I'll be ordering more from PJ. Here are close-ups.

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I torqued the rotor bolt to 22 ft-lbs (still haven't adjusted to metric torque settings) using a slap wrench to hold the rotor. The alternator side was then [mostly] buttoned up.

K27wXol.jpg


The split collars on the headers were very rusty and stuck together when I removed the exhaust, so I gave them a soak in phosphoric acid and then painted them with a high-temp engine paint for future rust protection. The headers are pretty rough and I have a spare set that I eventually hope to clean and have re-chromed. For now, the rusty ones go back on.

4SoxptJ.jpg


I didn't take any noteworthy pictures on the clutch side. I had three sets of clutch springs: original, EBC, and an NOS set that arrived today. I compared the springs in terms of their geometry (wire diameter, coil diameter, number of active coils) as well as the preload. I estimated the preload by installing a spring, tightening the bolt until the point that resistance is felt, and then counting the number of full turns required to seat the bolt. It took about 7 turns with the original and NOS springs and 10 turns with the EBC springs, meaning the EBC springs are compressed 3mm more than the Honda springs during installation. It seems like the EBC springs create a heavier pull and that's not what I'm going for, so I ruled those springs out. The NOS springs use thicker wire (3.3mm versus 2.9mm) and their lengths are about the same as the originals, so I opted for the original springs. I guess I can swap the springs at a later time if I don't like the feel.

I finished the garage session by buttoning up everything, installing the exhaust, and adding fresh oil. Hopefully tomorrow I will be able to set up the clutch and make a careful pre-ride inspection before going out for a short test ride. I need to make sure the replacement brake pedal is set up properly and check the adjustment on the rear brake switch. I'll check tire pressures as well, since the bike has been sitting for a little while.

KTOnZI1.jpg
 
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Good headers are hard to find. I went through 3 pair to get ones that could at least polish a little. They are still crusty where you can't see, but that was a big improvement. Your headers look fine...I think that is called Patina....:)
 
Good headers are hard to find. I went through 3 pair to get ones that could at least polish a little. They are still crusty where you can't see, but that was a big improvement. Your headers look fine...I think that is called Patina....:)
I'm assuming it's a thing that the CB360 headers rust a lot more on the inside faces? Both of the sets I've had show that pattern, moreso than CB450 headers I've seen.
 
I'm assuming it's a thing that the CB360 headers rust a lot more on the inside faces? Both of the sets I've had show that pattern, moreso than CB450 headers I've seen.
The engine facing surfaces have all rusted first on the few sets of headers I've seen. Maybe because the inside surface is a little hotter? I had aftermarket pipes on and they rust far quicker than stock pipes. The stock pipes are pretty heavy duty.
 
I had most of the afternoon to get back to work on the bike. The stuck clutch plates made a good excuse to refresh the bike in other ways and it took a little time to gather all of the parts. I ordered a new set of Honda clutch springs and received them today. I had already received the new rotor from Rick's Electrics and the starter block-off that @crazypj fabricated, so today was the day to put it all back together.

LyffbrC.jpg


Every motorcycle should have at least one shiny part and I have to thank PJ for putting a nice shine on the outer face of the plug. The plug is snug, but wasn't difficult to install. In contrast, the "commercial" one that I installed on my CB350 project was a little too tight and has a tendency to chew up the o-ring, so I expect I'll be ordering more from PJ. Here are close-ups.

lYD8XxG.jpg
HOb5Q7T.jpg


I torqued the rotor bolt to 22 ft-lbs (still haven't adjusted to metric torque settings) using a slap wrench to hold the rotor. The alternator side was then [mostly] buttoned up.

K27wXol.jpg


The split collars on the headers were very rusty and stuck together when I removed the exhaust, so I gave them a soak in phosphoric acid and then painted them with a high-temp engine paint for future rust protection. The headers are pretty rough and I have a spare set that I eventually hope to clean and have re-chromed. For now, the rusty ones go back on.

4SoxptJ.jpg


I didn't take any noteworthy pictures on the clutch side. I had three sets of clutch springs: original, EBC, and an NOS set that arrived today. I compared the springs in terms of their geometry (wire diameter, coil diameter, number of active coils) as well as the preload. I estimated the preload by installing a spring, tightening the bolt until the point that resistance is felt, and then counting the number of full turns required to seat the bolt. It took about 7 turns with the original and NOS springs and 10 turns with the EBC springs, meaning the EBC springs are compressed 3mm more than the Honda springs during installation. It seems like the EBC springs create a heavier pull and that's not what I'm going for, so I ruled those springs out. The NOS springs use thicker wire (3.3mm versus 2.9mm) and their lengths are about the same as the originals, so I opted for the original springs. I guess I can swap the springs at a later time if I don't like the feel.

I finished the garage session by buttoning up everything, installing the exhaust, and adding fresh oil. Hopefully tomorrow I will be able to set up the clutch and make a careful pre-ride inspection before going out for a short test ride. I need to make sure the replacement brake pedal is set up properly and check the adjustment on the rear brake switch. I'll check tire pressures as well, since the bike has been sitting for a little while.

KTOnZI1.jpg
The right-side muffler looks good.
 
I did make a short test ride yesterday — only about 2 miles. The Keihin 723A carbs necessitate a 1-to-2 throttle cable and every time I remove and replace the tank I have to be very careful to get the cable set up correctly. If it's not done right, the left carb cable will pop out of the junction housing and the throttle arm on the carburetor won't seat, leading to a high idle. I thought I had a good routing, but realized quickly that it needed to be adjusted. The bike seemed a bit hot when I got back to my garage, but I will chalk that up to the warm weather, stop-and-go traffic, and the higher than normal idle. I had also used a bit of chrome polish on the headers and mufflers after reassembly and the residue was burning off the pipes. I think unfamiliar smells always set off alarms for me, so I wanted to be very cautious about verifying the fact that oil is reaching the top end. I opened the tappet covers on the exhaust side and used a zip-tie dipstick to verify that the oil reservoirs for the cam had a good supply of oil. The oil on the stick looked fresh, too, so hopefully all is well there. I finished up by lifting the tank up and fiddling with the throttle cable junction housing until it found its happy place below and adjacent to the right ignition coil.

I hope to do more and longer [test] rides soon. In particular, I need to renew inspections and registration on my three riders this month!

The right-side muffler looks good.
Thanks, Bill. I'm sure you remember that I found that one on eBay after the previous one was damaged when my bike fell over while parked on hot, soft asphalt. The owner of the shop I deal with is an excellent welder and he patched up a couple of spots on the back side of this eBay muffler really well. How is its predecessor faring?
 
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I did make a short test ride yesterday — only about 2 miles. The Keihin 723A carbs necessitate a 1-to-2 throttle cable and every time I remove and replace the tank I have to be very careful to get the cable set up correctly. If it's not done right, the left carb cable will pop out of the junction housing and the throttle arm on the carburetor won't seat, leading to a high idle. I thought I had a good routing, but realized quickly that it needed to be adjusted. The bike seemed a bit hot when I got back to my garage, but I will chalk that up to the warm weather, stop-and-go traffic, and the higher than normal idle. I had also used a bit of chrome polish on the headers and mufflers after reassembly and the residue was burning off the pipes. I think unfamiliar smells always set off alarms for me, so I wanted to be very cautious about verifying the fact that oil is reaching the top end. I opened the tappet covers on the exhaust side and used a zip-tie dipstick to verify that the oil reservoirs for the cam had a good supply of oil. The oil on the stick looked fresh, too, so hopefully all is well there. I finished up by lifting the tank up and fiddling with the throttle cable junction housing until it found its happy place below and adjacent to the right ignition coil.

I hope to do more and longer [test] rides soon. In particular, I need to renew inspections and registration on my three riders this month!


Thanks, Bill. I'm sure you remember that I found that one on Ebay after the previous one was damaged when my bike fell over while parked on hot, soft asphalt. The owner of the shop I deal with is an excellent welder and he patched up a couple of spots on the back side of this eBay muffler really well. How is its predecessor faring?
Brody,I haven't worked on the muffler you've given to me yet,but I plan to;I want to complete the GS450 project first.
The bike was purchased by a guy who bought it at a charity auction from the original owner.. cheap;it was a non-runner and looked terrible when I first got it and it still needs more of my time & $ to have it be a dependable daily driver.
The 'good' is it is being sorted and getting close to being less of a 'charity case' that was completely neglected by it's original owner;it's finally up and running/riding during it's upward journey.

I'm glad you're sorting through your throttle cable routing,which can be an adventure;the 'path of least resistance' and less binding spots is always best.
I hope to find a reasonable chrome plating shop;I don't mind sending parts away.
I need some exhausts which have already been repaired plus the CB200T front fender,etc. done and am still looking for a reasonable 'plater'.
 
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I want to complete the GS450 project first.
The bike was purchased by a guy who bought it at a charity auction from the original owner.. cheap;it was a non-runner and looked terrible when I first got it and it still needs more of my time & $ to have it be a dependable daily driver.
The 'good' is it is being sorted and getting close to being less of a 'charity case' that was completely neglected by it's original owner;it's finally up and running/riding during it's upward journey.
We don't get to see enough of your work here on the forum. This sounds like a cool and worthwhile project. I take it the guy who bought it at auction gave up on it and sold it to you?
 
We don't get to see enough of your work here on the forum. This sounds like a cool and worthwhile project. I take it the guy who bought it at auction gave up on it and sold it to you?
Yes,the man who bought it at the auction in SF was advertising it on CL.
I made him a great offer on it and he jumped at it.
I wanted it for a sentimental reason.
 
My right side engine cover was leaking through the gasket after the recent work. All of the gasket surfaces were clean, but I had used a sort of paper type gasket, similar to the one linked below.


I have used that style before without trouble, but perhaps in a less critical area. The gasket I installed this morning comes from a D&K non-asbestos full gasket kit that I acquired from a friend several years ago. Hopefully it will cure the leak.

I don't think there is anything more embarrassing for a motorcycle forum member than an oil leak.
 
My right side engine cover was leaking through the gasket after the recent work. All of the gasket surfaces were clean, but I had used a sort of paper type gasket, similar to the one linked below.


I have used that style before without trouble, but perhaps in a less critical area. The gasket I installed this morning comes from a D&K non-asbestos full gasket kit that I acquired from a friend several years ago. Hopefully it will cure the leak.

I don't think there is anything more embarrassing for a motorcycle forum member than an oil leak.
These look like very good gaskets;I usually purchase Vesrah although sometimes the gaskets aren't available.
I recently purchased from Gasket Max in St. Charles,IL. and their gaskets have a resilient strength to them.
They are made in USA out of very good materials;a tough product which I install w/o gasket goop and this allows me to install and remove a few times w/o damaging the gaskets.
 
These look like very good gaskets;I usually purchase Vesrah although sometimes the gaskets aren't available.
Based on this experience, I was starting to wonder about this paper style. It seems a little thin and it gets points subtracted for the leak, so I'll probably avoid them for a while.
 
Based on this experience, I was starting to wonder about this paper style. It seems a little thin and it gets points subtracted for the leak, so I'll probably avoid them for a while.
I've bought from them (the tantric Buddhism ying yang logo) and they must make them to order because it always takes forever. Yes they are pretty thin too but they must have a great digital library because they do have some hard to find ones.
Cheap prices though.
I don't think I've used their 350 side cover ones yet.
 
I've been keeping an oil-free piece of cardboard under the motor since swapping out the clutch side gasket. It has remained dry, so I put about 4–5 miles on the bike this morning as a first real test. A couple of hours after returning, the cardboard is still oil-free.
 
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I've been keeping an oil-free piece of cardboard under the motor since swapping out the clutch side gasket. It has remained dry, so I put about 4–5 miles on the bike this morning as a first real test. A couple of hours after returning, the cardboard is still oil-free.
Always good to see it's still oil-tight.
 
Over the last year or so, the front disc brake has been squeaky, mainly at low speeds when coming to a stop. I tried different pads, scuffing the rotor, etc., which would yield temporary improvements in some cases.

Earlier this year, I finally noticed that the upper top bridge was cracked on the front side of the right fork and replaced it.

The disc brake seems much quieter now and it's dawning on me that the cracked top bridge may have been the reason for the squeak all along. I'm curious to hear opinions about that theory or any similar experiences anyone has had.
 
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The loose upper triple clamp created a bit of vibration at the caliper:not a solid connection up top?
Did this happen while under braking or after releasing ?
 
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The loose upper triple clamp created a bit of vibration at the caliper:not a solid connection?
Did this happen while under braking or after releasing ?
Yeah, I'm wondering if that could explain the vibration that caused the squeak. It was only while the brakes were applied and would stop when the brake was released.
 
About 12~15 years ago, the only time I had a major clutch cover oil leak was after I tried the 'advice' of greasing gasket on XS650.
It was the first and last time I'll ever do it.
As an 'experiment' it worked, but after 10 days being parked while on vay-kay the pint or so of oil to clean up was a pain when we got home
Probably wasn't the smartest thing to do changing gasket before leaving, I knew I wouldn't be home to monitor for leaks
 
I've finally managed to find some garage time and have been trying to figure out a strange problem with my CB360G.

I've been hearing what sounds like interference or dragging ever since I did some major work last summer. I installed an aftermarket rotor to solve a weak charging issue and replaced the clutch internals, while also adding some cooling holes to the clutch center. I was worried about the clutch side for the longest time, but I now believe the issue is with the rotor.

A week or so ago, I removed the stator and stator cover. As I turned the motor over by hand or kickstart, the noise was gone. So, I considered two options: (1) a new rotor from CMS and (2) an aftermarket stator to match the aftermarket rotor. Option (2) cost less to try and I now have the new stator installed. Unfortunately, the noise persists when the aftermarket rotor is installed, but goes away when the OEM rotor is swapped back in.

OEM rotor & aftermarket stator:

Aftermarket rotor with aftermarket stator:

I wonder if the aftermarket rotor is off-center or otherwise asymmetrical, if the stator could possibly be misaligned in the cover, or if the stator cover could be off slightly (locating dowels are intact).

So far, my only ideas are to buy an OEM rotor and go back to stock or try customer service to see what's up with the aftermarket rotor (maybe a replacement would work fine).

Thanks for any thoughts.
 
That's something I've yet to see/hear. It's not quite the sound I was expecting to hear, but it's there nonetheless. Hard to say, but a good used OEM rotor would be less expensive I'd think. Here's one for $37 shipped that looks pretty good.


Have you ruled out the possibility of something slightly different with the starter clutch? Or is this one starter delete? Can't recall.
 
Thanks, Tom. I'm worried that a used rotor may be weak like the one I have, but it's good to know that's another option.
That's something I've yet to see/hear. It's not quite the sound I was expecting to hear, but it's there nonetheless.
Me, either. In fact, turning it over by hand, it sounds almost innocuous, but at 1200+ rpm it sounds more like a dragging underneath the normal operating sounds. I had almost ruled out the rotor side, but finally decided to remove the stator as an experiment.

Have you ruled out the possibility of something slightly different with the starter clutch? Or is this one starter delete? Can't recall.
This bike has the starter delete package, all internals removed.
 
You’re sure the crankshaft hasn’t twisted? It’s a built up assembly so is another possibility.
I’ve never seen a rotor that’s out. Ever.
 
You’re sure the crankshaft hasn’t twisted? It’s a built up assembly so is another possibility.
I’ve never seen a rotor that’s out. Ever.
Thanks for the reply, Jay. I cannot say for sure and I'd be hard pressed to test that idea, but it's a good thought. For what it's worth, I don't think this crank has been touched since it rolled off the assembly line.

If the crank were off, would the explanation for the fact that the OEM stator turns over quietly be that it has worn down to correct for the eccentricity of the crank over the life of the bike?

Also, the rotor in question is aftermarket (from NH) and not OEM. Wanted to make sure you caught that.
 
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