Penton Owners Group

General Discussion => Penton Talk => Topic started by: Mike Lenz on March 10, 2005, 05:39:41 PM

Title: 100 jetting
Post by: Mike Lenz on March 10, 2005, 05:39:41 PM
Can someone help me out with jetting for a 100 as I was unable to find anything searching the site. I got my 73 100 with the Sachs top end and jackpiner bottom end started (started on third kick!), but its jetted way to rich. Its a 26mm Bing I think, but I cant find the size stamped on it? It has a 140 main, 45 pilot, 276 needle jet and a 5 ring needle in it, prob 125 jetting. Where is a good place to start? I got the cylinder from Ron Carbaugh and it has had some grinding done to it. Trying to get it all ready to go smoke those Hodes at the 100cc national in MO Memorial weekend!
The engine also has a stuffed crank(175),PVL and a alum 1976 125 clutch in it, plus 428 gearing. I put a newer style clutch cover, painted black, and a vintage older style black plastic ign cover on the engine to make it look smaller, red mx tank, tall seat, new rear pipe section and 73 exhaust guard, plus vintage Bilstein shocks. This little bike just looks awesome and should make those hodes shiver and run for cover!!
Title: 100 jetting
Post by: pketchum on March 10, 2005, 06:26:28 PM
Mike,

Does the 175 share the same stroke as the 100 engines?


Phil
Title: 100 jetting
Post by: john durrill on March 10, 2005, 06:35:24 PM
MIke,
 the difference between my 72 100 and a 125 was one size on the main an pilot jet.
 Here is what JP listed for a 100 cc sachs with the new 40-404 atomizer on a 27 mm bing
main-130
needle #4 ( 4 Groove's just below the clip slots)
needle jet- 276
pilot jet- 45 or 35
 My 72 100 with a magnito used 135 main, 273 needle jet, stock 125 needle ( dont remember what # it was) and a 35 pilot. That was with Golden Spectro at 40 to 1 and stock exhaust and foam air cleaner.
Title: 100 jetting
Post by: firstturn on March 10, 2005, 06:36:27 PM
Mikey,
  Nice job on the bike.  I am headed to the shop this weekend so I will get more info on the settings.  Start off with a 135 main and I will get back with on the rest this weekend.  Man I knew I should have kept that cylinder...just kidding.

Ron Carbaugh
Title: 100 jetting
Post by: john durrill on March 10, 2005, 06:38:59 PM
Phil , yep chuckle chuckle 54 mm stroke. thats why it was possible to do the 175 on a 125 Sachs bottom end with out a lot of outside machining.
 It was almost a drop on fit
:)
John D.
Title: 100 jetting
Post by: firstturn on March 10, 2005, 09:49:05 PM
John,
  You mean that 56mm stroke is wrong on my bike?

Ron Carbaugh
Title: 100 jetting
Post by: john durrill on March 11, 2005, 01:50:34 AM
Ron ,
 Wow!!!! That crank could go bad on you. Better send it to me straight away. We better get that one out of circulation befor it causes some one some damage.
[:p] I know I have a stock 54 mm one on hand to send you in its place! chuckle chuckle
John D.:D
Title: 100 jetting
Post by: firstturn on March 11, 2005, 08:21:09 AM
John,
  You'd do that for ME!  Sounds good should I also send you the cylinder to go with it?  Remember that some of my cylinders are hard to tune for...you know that second hand stuff.  You are always looking out for me John, thanks.[8D]

Ron Carbaugh
Title: 100 jetting
Post by: Mike Lenz on March 14, 2005, 08:42:58 PM
Thanks Guys, that will get me close. Ron, If your struggling with that jetting just send that pesky ported cylinder and Ill sort out the jetting and return it by the end of the decade.
Title: 100 jetting
Post by: firstturn on March 14, 2005, 09:15:21 PM
Mike,
  You are always the Gentleman.  I finally got the crank to work with two gaskets under the cylinder.[:p]

Ron Carbaugh