RB20 fit

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Grumpy225
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garry inglis wrote: Wed Apr 22, 2020 4:19 pm same here i used the standard studs from rayspeed as original 7.3mm thick rolled steel studs
That's good to know but riddle me this, previous cylinder fit without issue on the same MB studs.

I've been diving in and measuring every spot where it might bind and am coming up with matching numbers between kits!
10 inch Terror
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[/quote]

That's good to know but riddle me this, previous cylinder fit without issue on the same MB studs.

I've been diving in and measuring every spot where it might bind and am coming up with matching numbers between kits!
[/quote]

From memory I thinks it’s to do with some ports within the barrel breaking through into the stud holes on the original RB20 barrel castings. The stud holes were then ‘tapered’ slightly making them narrower where the ports were. This is where the fatter type studs can bind. I’m sure this is the case as I had the same issues and this was pointed out in a very long thread about it. Pete.
Grumpy225
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Posts: 650
Joined: Sat Nov 24, 2012 7:59 am
Main scooter: Gori200, rt195, ld150,rb20
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For anyone that’s interested, we were able to fix it by opening up the bottom of the stud hole with a carbide burr. Took almost nothing out and it freed up the binding point off the stud. It looks like the finish pass in the machine process might not have gone all the way through the cylinder but that’s a guess.

I don’t know if this was a machining flaw or just random weirdness in the casting. Either way, all fixed now.
10 inch Terror
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Posts: 1447
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Main scooter: Lambretta LI Imola 185
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Grumpy225 wrote: Mon May 18, 2020 6:04 pm For anyone that’s interested, we were able to fix it by opening up the bottom of the stud hole with a carbide burr. Took almost nothing out and it freed up the binding point off the stud. It looks like the finish pass in the machine process might not have gone all the way through the cylinder but that’s a guess.

I don’t know if this was a machining flaw or just random weirdness in the casting. Either way, all fixed now.
Love a happy ending me.
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