Supertrapp Exhaust: How many discs?

3 replies to this topic
  • Mantrasonica

Posted February 22, 2005 - 11:45 AM


Just doing some maintenance on the 87 600R I recently bought. I noticed it was leaking some fuel out of the secondary carb so I replaced the float needle. As soon as I did, the bike seemed to be running really lean (major popping on deceleration). The 'Trapp has 20 discs on it. I wonder if the previous owner was trying to "fix" a rich condition by adding more discs, but I really don't know that much about how a trapp exhaust is supposed to work. The airbox also had several holes bored into it which I have covered with foil tape. Not sure if the carbs have been re-jetted, but I intend to put them back to stock if it has been messed with. Since I really don't need any more performance over stock, I was wondering how many discs I should be running? Will a Supertrapp pipe perform well with stock jetting? Thanks for your help.

  • StevePSD

Posted February 22, 2005 - 12:54 PM


I am running 8 disc's on my soon-to-be-removed supertrapp on my '87. The bike also has a UNI filter. The jetting is nowhere near stock. based upon how my bike runs (2500ft altitude) you need to rejet from stock.

Stock Jetting:
Main Jet's (both carbs) #122.
Slow Jet: #45
Primary carb neeedle in 4th groove, secondary carb needle on 2nd groove.

My bikes jetting:
Primary carb main jet: #125. Secondary carb main: #135
Slow Jet : #45 (might need to go up to a #48)
Primary carb needle in 5th (bottom) groove.
Secondary carb needle still on 2nd groove.

I did not do the jetting, but the bike runs real, real strong. The carb linkage was adjusted to delay the opening of the secondary carb slide which all but eliminates the bog off idle that the dual carb bikes were known for.

Hope this helps.

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  • Mantrasonica

Posted February 22, 2005 - 01:01 PM


I am running 8 disc's on my soon-to-be-removed supertrapp on my '87.

Thanks for the input. Just curious, why are you removing the Trapp? I'd really like to put the stock pipe back on, but I've been having some problems finding one. Is there something better?

  • StevePSD

Posted February 23, 2005 - 11:52 AM


I am removing the super-trapp since it does not meet the 96db noise level for that some dual-sport rides now enforce. Wello, I should not say that it won't meet it, but in order to due so you have to only run about 4 discs, with the quiet core, and then it runs like crap.

I just replaced it with a White Brothers E2 pipe.

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