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1988 bike

Scheduled Pinned Locked Moved DTR
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  • O oldman

    @Calum said in 1988 bike:

    @oldman they are not serviable as far as I am awake.

    Thanks Calum, ordered one from Portugal (second hand) that looks good without rust for a reasonable price. Other 3bn barrel arrived today freshly rebored @1.25 over standard, and has been tuned. No id marks to say who did it , messaged seller to see if he knows. Mick Abbey marks his work as far as I am aware so doubt its him. Be good to know though and a bonus it's done. Will post a pic up later.

    CalumC Offline
    CalumC Offline
    Calum
    wrote on last edited by
    #17

    @oldman What engine are you fitting this to?

    3MB barrels and 3BN barrels are not interchangable!

    The 3BN has a larger bore, therefore shorter stroke. If you fit this onto an engine designed to have a 3MB cylinder, you could risk the piston hitting the cylinder head.

    It is very minimal, but they are different strokes.

    Always Originate, Never Pirate!

    O 1 Reply Last reply
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    • CalumC Calum

      @oldman What engine are you fitting this to?

      3MB barrels and 3BN barrels are not interchangable!

      The 3BN has a larger bore, therefore shorter stroke. If you fit this onto an engine designed to have a 3MB cylinder, you could risk the piston hitting the cylinder head.

      It is very minimal, but they are different strokes.

      O Offline
      O Offline
      oldman
      wrote on last edited by
      #18

      @Calum it's the 88 bike engine, same as the barrel that came off, 89 bikes changed to accommodate new carb amongst other things, is that right? Matching frame and engine nos so original engine

      CalumC 1 Reply Last reply
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      • O Offline
        O Offline
        oldman
        wrote on last edited by
        #19

        By the way, I mean the 88 bike I am building (endurance blue), not the red one.

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        • O oldman

          @Calum it's the 88 bike engine, same as the barrel that came off, 89 bikes changed to accommodate new carb amongst other things, is that right? Matching frame and engine nos so original engine

          CalumC Offline
          CalumC Offline
          Calum
          wrote on last edited by
          #20

          @oldman So the original barrel was a 3BN. I have only seen them on the 88's. You would just want to double up on the base gasket is all, I'd expect.

          Always Originate, Never Pirate!

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          • O Offline
            O Offline
            oldman
            wrote on last edited by
            #21

            Will not need to though if it's an 88 engine? Just need to make sure crank is correct for stroke, will check part nos to be sure.

            CalumC 1 Reply Last reply
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            • O oldman

              Will not need to though if it's an 88 engine? Just need to make sure crank is correct for stroke, will check part nos to be sure.

              CalumC Offline
              CalumC Offline
              Calum
              wrote on last edited by
              #22

              @oldman If it was running a 3MB and you put a 3BN barrel on it, the stroke will be too long. Is it the crank, is it the rod? I don't know. But the stroke is definitely different. So you will want to make sure you have clearance.

              Always Originate, Never Pirate!

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              • O Offline
                O Offline
                oldman
                wrote on last edited by
                #23

                Checked fowlers for part no, con rod for 88 listed as separate item, later years checked a(89 and 1990) and shows discontinued with no part nos? Have ordered a genuine 88 one to be sure but any info you have useful? Original barrel was already 1.75 over hence the replacement

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                • O Offline
                  O Offline
                  oldman
                  wrote on last edited by
                  #24

                  It's definitely an 88 bike and engine, the barrel was consistent with engine and I did have a spare 3mb barrel but sourced like for like. Cant be sure con rod in engine is correct hence ordering correct one from fowlers. Could be whole crank differs from later bikes but don't know (yet) will check clearances as built, lucky to find a matching barrel to be honest

                  CalumC 1 Reply Last reply
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                  • O oldman

                    It's definitely an 88 bike and engine, the barrel was consistent with engine and I did have a spare 3mb barrel but sourced like for like. Cant be sure con rod in engine is correct hence ordering correct one from fowlers. Could be whole crank differs from later bikes but don't know (yet) will check clearances as built, lucky to find a matching barrel to be honest

                    CalumC Offline
                    CalumC Offline
                    Calum
                    wrote on last edited by
                    #25

                    @oldman Yeah this.

                    The manual specifies both the bore and stroke for the 3BN, I'm sure. I don't have it to hand.

                    It is so minor I doubt it'll be too much of a problem. Powervalves are not interchangeable though.

                    As said, doubling up on base gasket will do the trick. My worry is that the con rod is designed to stretch and compress, how close will it be at 12k RPM is anyones guess!

                    Always Originate, Never Pirate!

                    O 1 Reply Last reply
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                    • O Offline
                      O Offline
                      oldman
                      wrote on last edited by
                      #26

                      Have the original powervalve fortunately, the manual is. 4 or. 04 difference I think from memory, Will be checking when assembling .

                      D 1 Reply Last reply
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                      • O oldman

                        Have the original powervalve fortunately, the manual is. 4 or. 04 difference I think from memory, Will be checking when assembling .

                        D Offline
                        D Offline
                        DTR+NSR
                        wrote on last edited by
                        #27

                        My understanding is the 1988 has the BN barrel and slightly longer stroke 0.5mm or something. 88 on wards they had slightly bigger bore and shorter stroke. Think if you mix and match parts you can end up with a 135cc or similar.

                        1 Reply Last reply
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                        • CalumC Calum

                          @oldman Yeah this.

                          The manual specifies both the bore and stroke for the 3BN, I'm sure. I don't have it to hand.

                          It is so minor I doubt it'll be too much of a problem. Powervalves are not interchangeable though.

                          As said, doubling up on base gasket will do the trick. My worry is that the con rod is designed to stretch and compress, how close will it be at 12k RPM is anyones guess!

                          O Offline
                          O Offline
                          oldman
                          wrote on last edited by
                          #28

                          @Calum said in 1988 bike:

                          @oldman Yeah this.

                          The manual specifies both the bore and stroke for the 3BN, I'm sure. I don't have it to hand.

                          It is so minor I doubt it'll be too much of a problem. Powervalves are not interchangeable though.

                          As said, doubling up on base gasket will do the trick. My worry is that the con rod is designed to stretch and compress, how close will it be at 12k RPM is anyones guess!

                          Hello Calum,What's the difference with the powervalve? Have measured and dry assembled and seems no different than one that came with bike, bar original has no grooves for seals and diamond style pulley shaft on end? Frame back but waiting for rack, grab rail, footrest hangers, suspension spring, etc.

                          CalumC 1 Reply Last reply
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                          • O oldman

                            @Calum said in 1988 bike:

                            @oldman Yeah this.

                            The manual specifies both the bore and stroke for the 3BN, I'm sure. I don't have it to hand.

                            It is so minor I doubt it'll be too much of a problem. Powervalves are not interchangeable though.

                            As said, doubling up on base gasket will do the trick. My worry is that the con rod is designed to stretch and compress, how close will it be at 12k RPM is anyones guess!

                            Hello Calum,What's the difference with the powervalve? Have measured and dry assembled and seems no different than one that came with bike, bar original has no grooves for seals and diamond style pulley shaft on end? Frame back but waiting for rack, grab rail, footrest hangers, suspension spring, etc.

                            CalumC Offline
                            CalumC Offline
                            Calum
                            wrote on last edited by
                            #29

                            @oldman I must be thinking 4FU and 3MB.

                            One of them didn't fit.

                            Always Originate, Never Pirate!

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                            • O Offline
                              O Offline
                              oldman
                              wrote on last edited by
                              #30

                              OK, thanks Calum. Replacement shock arrived and it's worse than the one I need to replace sadly. Lower ball joint corroded and worn and corrosion on plunger shaft has damaged the seal, very little damping going on. Will keep looking for a decent one.

                              CalumC D 2 Replies Last reply
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                              • O oldman

                                OK, thanks Calum. Replacement shock arrived and it's worse than the one I need to replace sadly. Lower ball joint corroded and worn and corrosion on plunger shaft has damaged the seal, very little damping going on. Will keep looking for a decent one.

                                CalumC Offline
                                CalumC Offline
                                Calum
                                wrote on last edited by
                                #31

                                @oldman FFS :@

                                Always Originate, Never Pirate!

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                                • O oldman

                                  OK, thanks Calum. Replacement shock arrived and it's worse than the one I need to replace sadly. Lower ball joint corroded and worn and corrosion on plunger shaft has damaged the seal, very little damping going on. Will keep looking for a decent one.

                                  D Offline
                                  D Offline
                                  dan28
                                  wrote on last edited by
                                  #32

                                  @oldman said in 1988 bike:

                                  OK, thanks Calum. Replacement shock arrived and it's worse than the one I need to replace sadly. Lower ball joint corroded and worn and corrosion on plunger shaft has damaged the seal, very little damping going on. Will keep looking for a decent one.

                                  look for a shock from a newer bike they have a white spring an fit on the 89 model

                                  1 Reply Last reply
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                                  • O Offline
                                    O Offline
                                    oldman
                                    wrote on last edited by
                                    #33

                                    Finally got a decent shock, waiting for powdercoating to return (have frame back though)so I can start rebuild. Seller of faulty shock not responded yet to return for refund, but covered via PayPal. Looked at getting a new indicator switch gear assembly and they are over £150. Put that on the wish list with everything else. Photos will be posted when there is something to show!

                                    1 Reply Last reply
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                                    • O Offline
                                      O Offline
                                      oldman
                                      wrote on last edited by
                                      #34

                                      Powdercoating back bar 2 items that should be here later this week, now where did I leave the assembly instructions????20190623_231148-460x818.jpg

                                      1 Reply Last reply
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                                      • CalumC Offline
                                        CalumC Offline
                                        Calum
                                        wrote on last edited by
                                        #35

                                        Haha that looks fantastic!

                                        Always Originate, Never Pirate!

                                        1 Reply Last reply
                                        0
                                        • O Offline
                                          O Offline
                                          oldman
                                          wrote on last edited by oldman
                                          #36

                                          Thought I had most of it but still missing plenty of bolts and fixings. Returned some of the plating, looked bad to be honest. On top of that rats have chewed the brake pipes on my van so that's being recovered on a flatbed truck tomorrow, revenge for shooting one. Started off with the abs light coming on, took to garage and sensor wire cut. Went to take it for repair and no brakes at all, other rear sensor wire chewed and brake fluid squirting out of chewed hose. How lucky am I

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