False Neutrals

[MattyQ]

Hi , I am interested in the solve for with the Sachs 6B motor  , as far as false neutrals go and issues with the ignition ?  Depending on who i talk to , the motor is tops or its average and tempermental.

Thanks ,

Q

Matthew Quinlan

[Steve Minor]

Try Doug Wilford. His email address is found on the Members section.

Steve Minor
Wilmington, NC

[jay cohen]

Even when adjusted properly there are still plenty of neutrals to be found. My Six Days was adjusted and set up by Doug and I still find tons of neutrals. To avoid hitting a few, I put on a 60 tooth rear sprocket. This alleviates using first gear. The biggest jump in the gearbox is between first and second gears. With a 60 tooth rear sprocket you can start off in second and avoid the gap. This is the achilles heal of the bike. The gearbox on these bikes is way too complicated and over-engineered. I don't know if there are any other things I can do or change in there to help our problem with missed shifts, maybe some of the experts here can help.

[Lew Mayer]

They don't charge any more for the extra neutrals. What a deal!:)

Lew Mayer

[lksseven]

You know, big changes can turn on the smallest of circumstances.  I wonder how history would be different if the Sachs gearbox had not been prone to false neutrals.

Larry Seale
I choose to ride

[TGTech]

If the Sachs transmission is shimmed, adjusted, and shifted properly, it is impossible to miss a gear. I know that sounds very weird, but it is true. Unfortunately, without having "you" (who ever would be interested) looking at the transmission shifting mechanism, it is very difficult to explain this.

Uncle Ted (Ted Penton) had me make 5 demonstration transmissions that were cut away, to be able to use as teaching tools, so I know exactly what this is all about.

The one thing in the statement that I made above, that many people don't understand, is the proper method of shifting the Sachs transmission. Unlike the more modern transmissions, the shifter of the Sachs transmission can not just be tapped and hope that it will move to the next gear. The shifter has to be moved to it's limit to properly shift it. If it is moved to the extent of it's movement, and the shimming and adjustment of the transmission is done properly, it is impossible to miss a gear.

Dane

[OUCWBOY]

I agree with Dane 100%. Having raced a Penton for two years and worked on a local Monark racer's bike for another 18 months. I never had any problems with missed gears and neither did the rider on the Monark. It's proper adjustments and proper shifting. All the negative shift problems are more than likely improper shifing. I even did most of my shifting without the clutch and still never had problems. My advise is to learn how to shift these wonderful machines. Want to ride a machine with real shift problems, try an early Jap bike!!!

Donny Smith
Paragould, AR

[Rain Man]

I don't have any problems shifting up, its always shifting down that I find neutral, especially on a significant climb.
  Alot of times I'll just close the throttle and screw the clutch [8D]

Raymond
 Down East Pentons

[NYPenton125]

Matt,

 I'm in the process of rebuilding my '72 SixDay and can tell you the transmission is probably the trickiest part of this project.  Depending on your mechanical experience, you may want tackle this yourself.  First off, get ahold of an owner's manual for your bike, this is invaluable.  It lays out in fairly clear steps the process of engine/tranmission dismantle and rebuild.  As Dane said, the transmission must be properly adjusted to eliminate the false neutrals. This article
http://new.photos.yahoo.com/sachs175/album/576460762364397382  was recommended by the POG and it really helped make the proper adjustments. Also, you'll need the "Shift Adjustment Tool", and shims available from Al Buehner.  (//www.pentonpartsusa.com) Take your time and have patience with this project (if you choose to attempt it), also be sure to check back at the POG forums for any advice along the way.  Good luck!

Matt Burns

[MattyQ]

Thanks for all the info , I just need to find one of those sweet machines first !  

Have a great one !
 
  Q

Matthew Quinlan

[dkwkid]

They will shift O.K. if shimmed to spec. I don"t care how well it is adjusted-you WILL miss the shift from 3rd down to 2nd at times. It will go past into neutral. Poking around the woods at 15mph you may never miss a shift, but in MX where races are won or lost with the shift lever and the throttle pinned you will find gaps you never knew existed.

[OUCWBOY]

I am afraid I have to disagree with some of the statements made here. Like I said, having raced MX and even short track on my Six Day and tuning the GS Pro Monark for a rider that was much faster than 95% of the MX'er in that era and we never had those problems. My 74 1/2 shifts perfect if you know how to shift the Sachs engines. I am betting that most folks don't know how to do it properly, like Dane stated. The ONLY time a problem ever existed is when the shift key was getting worn. Keep the trans shimmed properly, fresh shift key and proper adjustments and use a long throw when shifting and you shouldn't have any problems.

Donny Smith
Paragould, AR

[sixdazed]

I agree with Donny and Dane.Back in the day when i didn't know any better i thought the Sachs' motors just didn't shift properly.After having ridden properly set up,fresh,Doug Wilford motors here recently i can say they shift fine as long as you make a positive shift.I remember the Pentons i raced in the 70's shifted ok when new,then my sponsor installed Koba kits,etc. and it still never shifted as good as when it was new.Probably needed shift key/adjustment,etc.From what i remember of the 70's......
                                               Ric

ric emmal

[TGTech]

There are three key points regarding Sachs shifting: shimming, adjustment and shifting. The shimming is the first and most important, because if the transmission and shifting mechanism aren't shimmed properly, you won't be able to adjust the transmission properly. Second, the adjustment. The bottom line is this: when you hold the shifter to it's limit, (with the shifter mechanism cams AWAY from the pawl)in either direction, there should be some "play" in the fork on the end of the shift rod. If there is not, then the transmission will not adjust properly, period. If you can't get play in the fork to rod connection, then the the plate that holds the selector boss needs to be replaced. That then limits the travel of the selector boss and should give you the play that you need. Finally, the shifting is crucial. You can't just tap the lever and hope that it goes to the next gear. You need to move the lever to the extent of it's travel. If you do that and everything else is set up right, it is impossible to miss a gear, because the pawl is locked into the selector boss and that takes the shift arm and rod to the proper position.

If you have one of the older transmission versions with the locking arm, toss that and go to the stop cams that hold the pawl into the selector boss.

Dane

[Lew Mayer]

Dane, I got two out of three, shimming and adjustment. Now if I can just get the shifting down. Old bad habits are hard to break.[B)]

Lew Mayer