Author Topic: How to split silencer from header pipe 1975 rd200  (Read 882 times)

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Offline Fredswat

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How to split silencer from header pipe 1975 rd200
« on: September 27, 2017, 08:27:52 PM »
My RD200b  project has some really knackered silencers but the headers and castle nut fixings look restorable .  I just don't know how to undo the castle nuts .  Is their a special service tool that was used back in the day ? anyone got any ideas
77 RD400c
81 RD350LC
74 RD350A
89 TDR 250
74 RD200a
75 Kawasaki Z1b 
72 Kawasaki H1d
76 Suzuki Gt750
89 Suzuki RGV250 Vj21
71 Suzuki T500R
76 Honda cd175 
85 Honda c90
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48 Royal Enfield J2

Offline Johncb500

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Re: How to split silencer from header pipe 1975 rd200
« Reply #1 on: September 27, 2017, 08:53:18 PM »
are they the same as the 125 ?

  its a simple screw thread,ideally use a C spanner,or carefully tap with a blunt drift they should loosen ok
lifelong rider,laterly with Honda,now a little RD as well

  1355

Offline Fredswat

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Re: How to split silencer from header pipe 1975 rd200
« Reply #2 on: September 28, 2017, 12:49:39 PM »
Thanks for the response. I think they are the same as the 125.  I went to the yambits website and found they sell replacement castle nuts and a C spanner .  Thanks I will give it a go with a blunt drift or a strap wrench before investing in the C spanner.  I guess they haven't been undone in 40 odd years so I am expecting a fight
77 RD400c
81 RD350LC
74 RD350A
89 TDR 250
74 RD200a
75 Kawasaki Z1b 
72 Kawasaki H1d
76 Suzuki Gt750
89 Suzuki RGV250 Vj21
71 Suzuki T500R
76 Honda cd175 
85 Honda c90
03 Aprilia RS125
48 Royal Enfield J2

Offline hachey

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Re: How to split silencer from header pipe 1975 rd200
« Reply #3 on: September 28, 2017, 01:06:34 PM »
Thanks for the response. I think they are the same as the 125.  I went to the yambits website and found they sell replacement castle nuts and a C spanner .  Thanks I will give it a go with a blunt drift or a strap wrench before investing in the C spanner.  I guess they haven't been undone in 40 odd years so I am expecting a fight

You might as well get the gasket from yambits too, theyll likely need replacing. between silencer and header pipe there is a nylon or fibre type gasket. I'm only saying this because mine were really bad. They are funny to fit if you haven't before (i found).

Offline Fredswat

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Re: How to split silencer from header pipe 1975 rd200
« Reply #4 on: September 28, 2017, 01:32:59 PM »
Thanks also.  Yes I saw that and have saved a shopping trolley with lots of things in including the gaskets .  Long way from reassembly right now.  In the really dirty phase cleaning, shot blasting etc before , Powder coat, chrome and Zinc plate.  I guess 12 months before it all comes back together if my other resto's are a measure
77 RD400c
81 RD350LC
74 RD350A
89 TDR 250
74 RD200a
75 Kawasaki Z1b 
72 Kawasaki H1d
76 Suzuki Gt750
89 Suzuki RGV250 Vj21
71 Suzuki T500R
76 Honda cd175 
85 Honda c90
03 Aprilia RS125
48 Royal Enfield J2

Offline Comms Guy

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Re: How to split silencer from header pipe 1975 rd200
« Reply #5 on: September 28, 2017, 09:14:55 PM »
Nice bike, Fredswat. Just doing a C myself. Another member of the Blue Oyster Club as I keep being told :o :o

Offline Fredswat

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Re: How to split silencer from header pipe 1975 rd200
« Reply #6 on: September 29, 2017, 12:14:26 PM »
Thanks Guy this is my fourth RD400 .  I had a nearly new one the same in 1978 when I was 17. Fell in love with rd's as a result of that first one. Always thought that the Marine blue was a gorgeous colour and the C model without the tail piece just looks right .  How far have you got ? - PS Managed to get the castle nuts off the Rd200 pipes but had to resort to using the Dremmel to split them .  Even with a C spanner and lots of heat and brute force they weren't having any . Oh well
77 RD400c
81 RD350LC
74 RD350A
89 TDR 250
74 RD200a
75 Kawasaki Z1b 
72 Kawasaki H1d
76 Suzuki Gt750
89 Suzuki RGV250 Vj21
71 Suzuki T500R
76 Honda cd175 
85 Honda c90
03 Aprilia RS125
48 Royal Enfield J2

Offline Astute Greaser

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Re: How to split silencer from header pipe 1975 rd200
« Reply #7 on: September 14, 2018, 05:02:37 PM »
Had same problem with 73 RD200A.
Tried everything with C spanner, chain wrench, penetrating fluid, applying torch. Any more force and I would have damaged silencer mounting studs.
However the fine pitch of the thread with bit of internal rust, it was never going to move.
Got patterned, new castle nuts and seals from Yambits. Note diameter of thread.
Take silencer off bike. Pull header out from silencer (the seal disappeared with the torch). Cut slot alongside of the castle nut at angle to length of silencer, so hacksaw missed silencer. to a depth short of hitting thread. Run hacksaw 90deg to silencer from castellations to end of silencer. Applied cold chisel to this end of slot, and tapped sharply with hammer. Nut split all along length. Carefully unwind nut to avoid cross threading. Wire brush and silencer thread was in near perfect condition. New nut wound down it a treat.
Seems drastic, first silencer took 2 hours messing around, second only 15 mins.