Home Forums Shifter Karts Stinger Sizing

This topic contains 7 replies, has 5 voices, and was last updated by  Chris Reinhardt 4 years, 9 months ago.

  • Author
  • #34942

    Chris Barrington

    Hey helpful folks,

    I have what appears to be an RLV pipe on my CR125R and the “stinger” (I hope I have that right) measures 1 and 1/16 of an inch OD.

    Would the RLV 3″ x 12″ silencer with an OD of 1 and 1/8 of an inch fit tightly over the stinger of the pipe?

    Since the next size down is too small, am I correct in assuming that the slight increase in size of the silencer is because they are measuring the OD of the silencer pipe?  If it’s 1/16″ wall tubing, then it should fit snuggly over the stinger, no?

    Lastly, when mounting the silencer, does it need to be welded on to the stinger, to keep the joint air tight?

    Thanks in advance.


  • #34974

    William Martin

    Don’t even think about welding it on…ok, too late for that, just don’t do it! Use springs between the hooks on the pipe & silencer, it needs to have some give, or the vibration will fatigue the metal & break something eventually.

    I don’t know about the fitting, you need to measure ID & OD, or if you have the parts to measure, just try putting them together…no need to over-think this. :-)


  • #34975

    Chris Barrington

    Thanks, William.  I haven’t purchased anything yet, which is why I’m asking.  I just want to be sure I get it right the first time, and order everything I need…like springs  :)

  • #34978

    Chris Barrington

    Found the pipe pictures and specs on RLV’s site…it’s an R2, with a 1″ inch OD.  I remeasured using the middle of the tape, rather than the end of the tape.  I know which one I need now  :)

  • #35105

    Byron Rothenhoefer

    R2 pipe? Most  series are running  either the RLV R4 or the SKUSA pro circuit pipe . The R2 pipe is very dated. Don’t know if you plan on racing at all or just track time, but most of the series running  stock/spec  honda mandate a pipe. (Assuming your cr125 falls into that category, it is the most popular shifter class)

    Stock Honda 13

  • #35132

    Chris Barrington

    Understood Byron.  This is a 14 year old chassis, just to get me started.  I don’t plan on racing this kart necessarily, but if I do, it will need a host of changes/upgrades.  It has a 40mm axle for instance.

  • #35133

    Charles Skowron

    In that case, an RLV R2 pipe is perfect if you are just starting out with a Spec Honda. From my understanding, the R2 has a much broader power band than other Stock Honda pipes, like the R4. Perfect if you are figuring out how to drive the thing.

    In the earlier days of Stock Moto, the R2 was THE original, and only legal, pipe for the class. As a result, the R2 is legal at any race you attend, except for the SKUSA events of course (or any race that runs strictly by the book SKUSA rules).

    Considering the problem many racers have been having with their R4 pipes cracking, why the governing bodies allowed other pipes besides the R2 in Stock Moto is beyond me. On the other had, adding other pipes besides the R2 is far from the worst parts inclusion the powers-that-be have legalized in this shifter class.


    C. Skowron

  • #35276

    Chris Reinhardt

    At the inception of the Stock Honda class, there were several pipes that were legal….  The RLV, RCE, and I believe a High Tech and McMillan…

    The RCE quickly became the pipe to have, and I’m sure Mr RLV wasn’t happy with that, and either he had the R4 added, or somebody else did to compete the RCE.  That was a good thing, because shortly after RCE went tits up!!!

    It’s really not a “spec” series, because they are not sealed motors, and some different parts are allowed in some areas, pipes and fuel systems being some of them…  I think that’s one the keys to it’s success, they are not exactly cookie cutter motors, a little different here and there, enough to keep everything interesting…

    Just my $0.02….



    Chris Reinhardt

    CR2 Motorsports


    XV Racing Products



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