Penton 125 ISDT?

[Cathump]

I'm a new Penton owner. I wanted one very badly as a kid in the 70's, but here in Yamacountry (East TN)they were not to be seen.

I have what I think is a 125 ISDT, and I do not know what year it is. The frame number is 407 7591 9.

Also I need a source for parts. The head gasket is blown, and the tranny is locked. Any help would be appreciated.

 

[Paul Danik]

First off I would like to welcome you to the land of Pentons!!! I am NOT going to ask how you got your name!!!!! As far as your machine goes, the 407 of your serial number indicates that your bike is a 1974 and was built in the 07 month, July. On the homepage of this site is a parts link, there are numerous parts suppliers listed. You can buy reprinted manuals and do the work yourself, or there are some top notch rebuild experts who can do the work for you.  I am sure that if you reply with how you would like to proceed with your project, you will get some great advice from some of the parts and rebuild experts who are active on this message board.    Again, welcome!!!!

 

[Cathump]

Thanks for the welcome.

I get a hard time over my name over on the Sabre forum all the time. It was ca thump at one time, but even I say cat hump now.

From what I can tell this bike is in great shape, other than what I mentioned before. I am a mechanic by trade, so I'll just pick up a manual and tear into it.

I was told that there is a key in the tranny that causes it to lock up.

 

[Paul Danik]

The problem may be in the topend or the bottom, or the gearbox.  I would take the right side cover off, four screws, and see if the flywheel will move at all.  Will the engine sprocket turn at all, or is it tight? Will the bike wheel around with the chain on??  That key you mentioned slides through notches in the gears to do the shifting.  When the key and its matching edges on the gears ware you will miss some shifts, but that won't make it lockup.  Although, nothing is impossible!!!!! It might be rusted together from sitting for a decade with water in the gearbox.
Let me know what happens.
Paul

 

[Cathump]

I almost hate to split the cases. This bike only has 384 miles on the odometer. The previous owner believes the tires, chain and sprockets are original. This bike almost looks new. It was running 3 weeks ago when I first looked at it. I rode it, and it shifted good. Then the owner called me, and told me the tranny was locked and gave me a VERY good deal.

 

[Doug Wilford]

Ca;  Take Pauls advice first. It just may well be the previous owner pulled the wrong plug on the bottom of the engine cases to change oil.  The larger funny looking bolt head is the stop for the kick starter.  If you cannot kick the engine over with the kickstarter that is probably the culprit.  It is best to remove the engine and split the cases to reposition the Kick start return spring to its' proper position.  It would be a good time to put in new main seals also.



Edited by - Doug Wilford on 01/27/2002  9:15:59 PM

[Cathump]

The engine kicks through easily. The trans is in neutral, and will not shift.

I do appreciate the heads up on the oil plug.

 

[Dwight Rudder]

It is the shift key. It is sheared. Doug Wilford is a master of the six speed Sachs and can fix it like new.
Cher'o,
Dwight Rudder

7 time ISDT / E medalist
7 time National Enduro Class Champion.

[Paul Danik]

I assume that the chain is on the bike. With the engine not running, put pressure down on the shifter and move the bike forward.  Also try and upshift using the same method. Does it engage into either gear??  Does it make a clikking noise??  I really don't know that we can assume for sure yet that the tranny is bad.  You said that the odometer only has 384 miles on it, but we don't know for sure if that is correct. For all I know the other owner left the gas on all night and filled the engine with fuel, it wouldn't kick and he thought it was locked up. Maybe the topend seized and cooled down enough to loosen up. I really don't know, but with a little playing around we should be able to narrow it down.  You said that it kicks over, have you had it running??




 

[Paul Danik]

Another thought, if the original foam air cleaner is still in the machine it might be braking down and getting sucked into the engine. The airfilter is located on the left side of the machine just below the seat behind the numberplate. The whole cover is a rather large triangular piece with 4 bolts.

 

[Cathump]

Ok, I had my wife push the bike around and sure enough, it shifts up and down, through all the gears, although it does not shift real smoothly. At a standstill it still will not shift.

It also has the stock filter, but it looks to be in decent shape. The petcocks were shut off when I picked it up also.

I'm sending for a repair manual, head/base gaskets, and a shift key tomorrow.

I will be riding this bike soon. I appreciate each of you. This seems like a family!!!!!

 

[Paul Danik]

Several parts need to line up in the gearbox for it to shift, hence it will not shift just sitting still. I  am still baffeled by the blown headgasket.  Those engines NEVER blew headgaskets.  Is there crud running out the top of the cylinder? What makes you think it is blown? I still wonder if the engine was full of fuel and some was compressed above the piston, maybe that locked the engine and maybe that is what is coming out the top. Have you tried to fire it up?? Paul

 

[Cathump]

The bike had been sitting since 1980 and the previous owner replaced the piston/rings back last year, but he did not replace the head gasket. I can only assume that he used a torque wrench when he put it all back together. The bike was running and rideable back in August when I first looked at it.

I know the head gasket is blown because when I kick it through, the compression and the air/fuel mix blows out between the head and barrel.

As far as the tranny, I'm still learning about this one. All my experience has been with Harleys and various Japanese bikes.

When I finish converting my TT to YZ front suspension, I will be able to spend more time on the ISDT.