Vintage Dirt Bike Q & A

Any one else like the stock OE pipe over the aftermarkets?...Ive tried them all and while the Pro-Form does offer more top end/RPMs it has massive wheel spin when it hits,the stocker seems to offer more all around grunt with decent overrev and trackable power delivery....Ive tried new,modern pipes,old aftermarkets ect and always go back to the OE....my motor is far from stock too porting by Bill Clemm,38 Mikuni,PVL....comments and suggestions are welcome..Thanks

By any chance do you know what your jetting specs are?

Is your 38mm Mikuni a round slide or flat slide?

Thank you
~JM~

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Big Block Cadillac Forum

My specs for the 38mm at sea level are as follows...

280 MJ
40 pilot
6DH7 needle (3rd notch)
2.5 slide
Q-6 NJ

Heavy duty port job,Jastco intake with the cylinder matched to it,milled head,PVL ign,various pipes as mentioned.

Thank you for the specs.

Is your carb a flate-slide or a round-slide?

Are you running a 32 to 1 mix?

Does that Jastco intake have a reed cage in it, or is the engine still a piston port engine?

Thanks again
~JM~

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Big Block Cadillac Forum

38 round slide (AHRMA legal)..no reed in the Jastco intake,32.1 Maxima 927 with 1/2 race and 1/2 pump gas 91

Excellent! Thanks for the info. This board needs more information on jetting specs & what is actually working.

I can't provide any feedback on any expansion chambers other than the DG pipe on eBay. That pipe is too loud for a street bike. In my info gathering on other pipes I have often heard that the OEM pipe was hard to beat. I'd like to try it & the Pro-Form pipe someday.

~JM~

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WWW.CADDY500.COM
The High Performance
Big Block Cadillac Forum