Penton Owners Group

General Discussion => Penton Talk => Topic started by: gooddirt on August 08, 2007, 10:10:02 PM

Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: gooddirt on August 08, 2007, 10:10:02 PM
Have a Sachs -B-top end that has been GS ported and milled head -28mm intake -Would it hurt or make much difference if I run a 27mm bing? I have installed the 404 Atomiserur-vaporizer [I think thats the number] and jetted it per John Penton specs. Will be racing at the AHRMA Farm this weekend so need feedback ASAP:D:D Thanks LG
Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: Ernie Phillips on August 09, 2007, 08:52:24 AM
I don't have experience with GS porting but race modified 5A & 6B with 30mm Bings.  The 5A has 140 MJ, 6B has 148 MJ.  I would go rich ... so my recomendation would be to get some bigger main jets and play it safe ... especially since you have bumped up the compression.  



Ernie P.
Chattanooga, TN
Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: socalmx on August 09, 2007, 10:12:23 AM
For now, you can run the 27mm Bing and probably get by but I would suggest looking for a 30mm Mikuni and really make that engine sing.
Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: Ron on August 09, 2007, 03:44:36 PM
I'm running a 30mm Mikuni on my ported 6B, with the jetting specs from Donny Smith (in the archives) in southern Calif.
RonW
Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: gooddirt on August 09, 2007, 08:40:54 PM
Thanks for all the info![:X]
Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: VICTOR MONZ on August 10, 2007, 06:03:20 PM
Larry:

I have a couple 28 mm carbs.....trade me some goodies for my "secret weapon".

VM

Barb is back!
Title: Running a 27mm on a 28mm intake??? HELP ASAP
Post by: smkt342 on August 11, 2007, 07:57:57 AM
If you need a Mikuni 30mm I have them new for $84.95 plus $7 shipping.  I'll be in vintage views next month with a mikuni ad.  

Keith Taylor (long time lurker, former penton owner but still love em)