B Sachs powered penton 125

[pklinck]

Paul and others,

In addition to replacing the choke plungers with new ones from Bing Int'l, I lowered the needles one notch on both 125s, so made it leaner.  I raced both of these 125 pentons and there was a big improvement in the overall running.  However, when the rpm is very low, I have trouble if the plug is really wet, in neutral, to work the throttle and get the rpms back up for the clean out.  The top rpm and power is good, even though dropping the needle down one notch.  It boils right down to just avoiding giving too much gas when it is bogged down and to be sure to drop it down into the next gear in time and thirdly, another small adjustment while we are getting closer.  

The bikes in general are now reliable for racing.  I will talk to some of you at the ISDTRR next week.  I race enduro again tomorrow with the KTM guys.

peter klinck

[gooddirt]

[?][?]Are you running the stock pipe with the spark and muffler insert? Drill some more or bigger holes on the insert larger end dome. did you cut the slide ? I cut a 2mm deep and 3mm wide notch and use the replacement automizer; what needle #4 or #5 ? How about to much oil on the air filter , oil mix to gas ratio, oil type, grade of gas old or fresh, spark plug heat range; a new plug?[:0]

[Daniel P. McEntee]

quote:Originally posted by pklinck

Paul and others,

In addition to replacing the choke plungers with new ones from Bing Int'l, I lowered the needles one notch on both 125s, so made it leaner.  I raced both of these 125 pentons and there was a big improvement in the overall running.  However, when the rpm is very low, I have trouble if the plug is really wet, in neutral, to work the throttle and get the rpms back up for the clean out.  The top rpm and power is good, even though dropping the needle down one notch.  It boils right down to just avoiding giving too much gas when it is bogged down and to be sure to drop it down into the next gear in time and thirdly, another small adjustment while we are getting closer.  

The bikes in general are now reliable for racing.  I will talk to some of you at the ISDTRR next week.  I race enduro again tomorrow with the KTM guys.

peter klinck

Hi Peter;
    Moving the needle doesn't affect the top end operation, the the mid range off of idle through about 3/4 throttle. Top end is affected by the main jet size. Make a high speed run at full throttle, then clutch it in while hitting your kill button, and coast to a stop. Then check your plug. That will be the best reading for checking top end. If you get a good plug reading after several of those, then you can work on mid range and try leaning out the mid range. If it blubbers on acceleration, it's too rich. If hit hesitates or falls flat, it's too lean. You can also have some kind of air flow restriction that causes it,such as an oil filter oiled too heavily, and also the clogged silencer and spark arrester. Make sure you have good air flow through the passages for the air/fuel mixture screw. All the little things add up. And double check the info about notching the slide also. Have fun at the ISDTRR. I was fortunate enough to attend in 2003 in Dalton, but can't make it this year. Have fun and ride safe.
   Dan McEntee

[Guenther68]

Hi Peter,

which BING Carb are you running onyour bike? 1/27/19?

Best regards
Guenther Vogt,
Hercules Club, Germany



******************************
Hercules-Interessengemeinschaft e.V.
URL: http://www.herculesig.de

******************************

[pklinck]

Paul,

Thanks for your trouble shooting and addressing the carb problem mentioned above at the ISDT reunion ride in North Adams last weekend.
Sure enough, your bringing a bag of carb jets to help solve this carb's problem and I'm sure, other trouble shooting issues with other riders was much appreciated.

So as you suggested, you and I took out the 140 main jet and installed a smaller 135 main for this 73' Sachs powered penton 125 and it made a great improvement when I was caught a few times with the rpm down on a stony hill.  That cured the problem.  I would agree, it is best to try to work out the jetting first rather than for example, cut the bottom of the slide initially as was suggested above.

In addition, I noticed the bike didn't hold an idle and I had to play with the adjustment during the race moving the slide up or down with the idle screw.  Well, the exhaust system was never cleaned as I thought after returning home.  I used the recent POG suggestion and burned the pipe red hot section by section until done using a oxy acetylene torch.  Wow, did I get a lot carbon out of that pipe.  Using an electrician's "snake", I ran the wire up and down with a flared end.   Especially noticed the center tube inside where a lot of material was removed.  I'll run it tomorrow for a test.  Thanks again Paul.

Guenther68,  My Bing carb is a 1/27/20

peter klinck

[gooddirt]

"Penton Carburetion Secrets"  1974 July article " you'll be pleased to know that even the 2mmx 3mm notch on the front of the slide , comes stock"  

 
 The Atomizer Number is # 40-404 ; this also is a PENTON FACTORY Tech  update.  
 
   Need I say more[?]

[Paul Danik]

Peter,

  It was a pleasure to meet you and visit with you at your own private Pentonville on the Hollerich Farm, as well as to get to look over your own version of the Cycleliner. Your Penton transporter brought back some great memories to Jack as he told us of learning to drive on the Penton Farm in pretty much the same truck in his younger days. If you could post a picture of your truck I am sure others would enjoy seeing it.

  I am glad the jet change we did helped, as you continue to sort out your machine I would suggest that you make only ONE change at a time, as you probably already do, or possibly put a carb on your bike from a perfectly running machine, with a cylinder of the same vintage, to see if the carb is the entire issue. Often times these issues are a combination of a number of factors and can be tricky to properly resolve.

   Here is a story about the carb on John's bike that he rode in the Legends Dual Sport ride that weekend, and the issue we had...
 
    I had brought along a complete carb, including the needle & slide, spring, cap, ect.. for use on the machine that John rode, as the one from that machine wasn't back to Jack from getting some replacement parts installed. The carb I brought was borrowed from a machine that had last seen use about 10 years ago at an ISDTRR and had a cylinder of similar vintage to the one it would be used on. I pulled the carb apart to clean it and saw that it had a 130 main jet, figuring that the dual sport would have a decent amount of road involved I changed the main to a 140, and did a very careful cleaning of the entire carb body, passage ways and jets.
   On Friday after unloading at the farm, I installed the carb, the machine started on the 3rd. kick and ran flawlessly on numerous test rides that day. I had brought along enough extra carbs, jets, and assorted items to be able to set up a Bing service center if needed, but everything was working fine...for now.

   Saturday morning I wanted to warm up the machine before we left, it started on the first kick, but it just didn't want to come off of idle and into the mid range properly, even after several runs and surely being properly warmed up. About that time John came over and wanted to try out the bike, I explained the situation to him, he sat on the machine and carefully worked the throttle, all the while using the clutch to put various loads on the engine, you could almost see the wheels spinning in his mind as he did this...all I could think of is how did such a perfectly running machine turn to crap overnight.
   John then took off on the machine and it was obvious it wasn't running properly in the low to mid range. When John returned he was all smiles, he said that all of a sudden the machine cleaned out and was now running perfectly.....he stated that he figured that a bit of water had accumulated in the float bowl and had caused the issue.  The bike then ran flawlessly the rest of the weekend and always started with ease
Paul

[pklinck]

Paul,

Thanks for your trouble shooting and addressing the carb problem mentioned above at the ISDT reunion ride in North Adams last weekend.
Sure enough, your bringing a bag of carb jets to help solve this carb's problem and I'm sure, other trouble shooting issues with other riders was much appreciated.

So as you suggested, you and I took out the 140 main jet and installed a smaller 135 main for this 73' Sachs powered penton 125 and it made a great improvement when I was caught a few times with the rpm down on a stony hill.  That cured the problem.  I would agree, it is best to try to work out the jetting first rather than for example, cut the bottom of the slide initially as was suggested above.

In addition, I noticed the bike didn't hold an idle and I had to play with the adjustment during the race moving the slide up or down with the idle screw.  Well, the exhaust system was never cleaned as I thought after returning home.  I used the recent POG suggestion and burned the pipe red hot section by section until done using a oxy acetylene torch.  Wow, did I get a lot carbon out of that pipe.  Using an electrician's "snake", I ran the wire up and down with a flared end.   Especially noticed the center tube inside where a lot of material was removed.  I'll run it tomorrow for a test.  Thanks again Paul.

Guenther68,  My Bing carb is a 1/27/20

peter klinck

[gooddirt]

"Penton Carburetion Secrets"  1974 July article " you'll be pleased to know that even the 2mmx 3mm notch on the front of the slide , comes stock"  

 
 The Atomizer Number is # 40-404 ; this also is a PENTON FACTORY Tech  update.  
 
   Need I say more[?]

[Paul Danik]

Peter,

  It was a pleasure to meet you and visit with you at your own private Pentonville on the Hollerich Farm, as well as to get to look over your own version of the Cycleliner. Your Penton transporter brought back some great memories to Jack as he told us of learning to drive on the Penton Farm in pretty much the same truck in his younger days. If you could post a picture of your truck I am sure others would enjoy seeing it.

  I am glad the jet change we did helped, as you continue to sort out your machine I would suggest that you make only ONE change at a time, as you probably already do, or possibly put a carb on your bike from a perfectly running machine, with a cylinder of the same vintage, to see if the carb is the entire issue. Often times these issues are a combination of a number of factors and can be tricky to properly resolve.

   Here is a story about the carb on John's bike that he rode in the Legends Dual Sport ride that weekend, and the issue we had...
 
    I had brought along a complete carb, including the needle & slide, spring, cap, ect.. for use on the machine that John rode, as the one from that machine wasn't back to Jack from getting some replacement parts installed. The carb I brought was borrowed from a machine that had last seen use about 10 years ago at an ISDTRR and had a cylinder of similar vintage to the one it would be used on. I pulled the carb apart to clean it and saw that it had a 130 main jet, figuring that the dual sport would have a decent amount of road involved I changed the main to a 140, and did a very careful cleaning of the entire carb body, passage ways and jets.
   On Friday after unloading at the farm, I installed the carb, the machine started on the 3rd. kick and ran flawlessly on numerous test rides that day. I had brought along enough extra carbs, jets, and assorted items to be able to set up a Bing service center if needed, but everything was working fine...for now.

   Saturday morning I wanted to warm up the machine before we left, it started on the first kick, but it just didn't want to come off of idle and into the mid range properly, even after several runs and surely being properly warmed up. About that time John came over and wanted to try out the bike, I explained the situation to him, he sat on the machine and carefully worked the throttle, all the while using the clutch to put various loads on the engine, you could almost see the wheels spinning in his mind as he did this...all I could think of is how did such a perfectly running machine turn to crap overnight.
   John then took off on the machine and it was obvious it wasn't running properly in the low to mid range. When John returned he was all smiles, he said that all of a sudden the machine cleaned out and was now running perfectly.....he stated that he figured that a bit of water had accumulated in the float bowl and had caused the issue.  The bike then ran flawlessly the rest of the weekend and always started with ease
Paul

[pklinck]

Paul and others,

Thanks once again for your (suggestions) and support in carb adjustments here and at the ISDTRR.

Yes, we (Paul and I)solved the low and mid range problems at the race with a good improvement in the woods for this 1973 penton 125.

After returning to Vermont, I did a test run and noticed the high end range power was a bit flat and not clean sounding.  I remembered Paul your first suggestion; "lower the needle not one (after testing) but 2 notches" if necessary.  I will back up a bit and try the 140 main jet again AND drop the needle again one more notch.

I'll try to operate photo bucket to see if I can load a photo of my "1951 camper or trailer", so to speak.

peter klinck

[Guenther68]

Hi Peter,

referring to Sachs and Bing the setting should be

Main jet 140
Needle jet 2,70
Needle #4
needle position 2
Idle speed jet 45

Best regards
Guenther Vogt,
Hercules Club, Germany



******************************
Hercules-Interessengemeinschaft e.V.
URL: http://www.herculesig.de

******************************