Hey everyone,I'm finally getting back to my RT360 project after it's been sitting on the back burner for a few years, and I'm running into some issues getting the clutch to work properly.A couple of years ago, I replaced the right-side crank seal due to excessive smoking. As part of that job, I had to remove the clutch basket. After reassembly, I ran the bike for about 30 minutes to burn out oil that had built up in the exhaust. Once the smoking subsided, I took it for a test ride—but the clutch pull was extremely hard, and worse, the clutch wasn’t even engaging. It's always had a stiff pull, but this time something was definitely off.Fast forward to now—I pulled the crankcase cover and noticed the clutch basket was moving side to side. Turns out, the clutch hub nut had backed off. I figured that must've been the issue.I tore everything down, cleaned, and reassembled the clutch using the OEM diagram from the owner’s manual. I also replaced a cracked nylon worm gear with a brass one. Adjusted the clutch per the manual—crankcase adjustment first, then lever adjustment. The lever now feels smooth and consistent.Before sealing everything up and adding oil, I wanted to check clutch function. With the bike in gear and the clutch lever pulled, I tried to spin the rear wheel—but it wouldn’t spin freely, which seems wrong, but maybe it would act differently with everything back together and new oil installed.While installing the side cover, I realized the gasket I ordered was incorrect—bolt holes didn’t line up—so I held off final assembly. In the meantime, I loosely installed the crankcase cover (no gasket) just to keep the internals clean. I put in a few bolts to hold it, then tested the clutch.Here’s where the real issue came back. When the cover is snugged down, the clutch lever becomes super hard to pull again, just like before. Watching closely, I noticed that pulling the clutch lever causes the crankcase cover to visibly shift—it’s contacting the pressure plate or outer basket. Once I loosen the cover bolts, the lever pulls much easier again.It should also be noted that this bike originally had an RT1-B crankcase, but it was swapped out for an RT3 crankcase to match the cylinder and the rest of the bike after the transmission blew up. There’s a possibility (though I honestly can’t remember) that I installed the original RT1 clutch assembly onto the newer RT3 cases. I didn’t think that would cause any problems, but the tight clutch pull and cover interference are starting to make me wonder if there are subtle differences between the RT1 and RT3 clutch assemblies that might be causing this issue. Here’s a video showing both the clutch basket and how it moves when the lever is pulled as well as how the crankcase cover moves when the clutch is pulled:
So here are my questions:

1. Why is the clutch hitting the crankcase cover when I pull the lever? Does the clutch assembly look like it is sitting too far out?
2. Is there a potential compatibility issue with RT1 and RT3 clutch assemblies?

Any help or advice would be hugely appreciated. Thanks in advance.

One of the RT experts will hopefully have some ideas...

It looks to me like the clutch is spaced out too far...  as evidenced by the gear alignment.  Maybe an extra washer or too thick a washer made it in behind the clutch?  

And I always cringe when someone says they used the parts diagram for assembly...  so often the diagrams are not correct or can be misleading...  like showing the flat roller bearing but not showing the thin washer that comes with and must be used with the flat bearing.  

It's also possible to easily "pinch" the flat bearing or thin washer under the basket.  A damaged bearing or washer will prevent the clutch basket from seating properly.

I'd pull the clutch off and post pics or video of the washers and flat bearing behind the basket exactly as they are installed.  

P.S.  I don't think the clutch changed between RT1 and RT3...  but an expert on that model will know.

Ditto on what mark said. Looks like the clutch basket is outboard too far. Primary gears should line up. The taper on the spacer 1 (item #16) will sometimes be too much and allow the thrust bearing and washer (item # 17) to slide down and get pinched when you tighten the nut. Put grease on it to hold it in place. I've bought new spacers and have noticed that the taper varies. On one of my riders I ground off 10 thousandths from the spacer to prevent the thrust bearing from sliding down when installing it. As Mark says the parts manual is not necessarily an accurate shop manual for assembly.
How many friction plates do you have? 360 will have 7 and 250 will have 6. Also there is a difference in thickness between plate, clutch 1 (item # 4) and plate, clutch 2 (item #8).

Send me a PM.

Can't see on my phone easily but are they new fibers & thicker than originals as they all add up to maybe what you see there pushing on the cover. Are your rubber spreader rings still in place with aftermarket fibers as aftermarket may not have clearance under them for the rubbers therefore stacking it all out & not compressing the fibers at all. Is there thread showing past the end of the hub nut as I'd expect there to be a few turns showing. Is the basket gear pretty much in line with the crank. If not then check all things behind the basket small kick gear. Only other random unlikely thing is if the circuit blew out of the case where the main shaft comes through the case then it would all move over limited by the cover. After all that, none of what I mentioned is very likely but gotta be a reason.

Thanks so much to everyone for your help and suggestions. I really appreciate all the input—it got me thinking in the right direction.

While I was taking the clutch apart to take photos and measurements, I found the issue. The notched gear that sits behind the clutch basket (just before the flat roller bearing) wasn’t fully seated in the notch on the basket. It was slightly misaligned, which caused the entire clutch basket to sit too far outward.

After spotting that, I noticed a small burr on the clutch basket that was preventing the gear from dropping into place correctly. I carefully filed the burr down, and once I did that, the gear fit nicely into the notch. Everything then went back together smoothly and now sits properly within the crankcase cover.

Fixing that not only solved the issue with the clutch hitting the cover and the super tight lever pull, but it also allowed the clutch to engage correctly—because the clutch basket was sitting farther out, I wasn't able to get the clutch to push out far enough to engage. Now everything feels and functions the way it should.

Thanks again for all the help—hopefully this will help someone else in the future.

Top marks. You can't beat learning by experience!!. There's so many trick to learn though that there seems to be no end.

Great job and congrats!