Can't get it running

[Andreas Piepke]

Good points. I'll get a new seal and a new gasket (already ordered) and then leak test the engine again. I'll lightly polish the crank sealing surface. The leak is very small and might indeed be due to some subtlety.
If fixing the air leak doesn't improve engine performance then I'll need to understand whether or not the clutch slips under load. Someone already pointed this out in this string of posts. I should probably start a new post if I have to do this.

Cheers and thanks for your continued interest!

Andreas

P.S.: Dave, I actually made a photo of the seal holder before installing the new seal in May 2014. The sealing surface didn't show any corrosion, have a look:

[adrian_goold]

I always use a smear of gasket goo on the outer edge of the seal when pressing it in to ensure a sealing surface when using the steel edged seals.
And yes, i would be pressing the seal in further to ensure both lips are on the flat surface.

When installing put a smear of a molykote o-ring or seal grease to the lip of the seal.



Regards,
Adrian Goold #101
http://www.ozktm.com
[/URL]
'73 175 Rebuilt|2x'74.5 250 |'74.5 400 Restoring|2 x'76 MC5 250 |'76 MC5 400 |'78 250 in pieces|'81 250 | '81 495|74 CZ 250|

[G Ellis]

Your trouble is that the seal is to far out. The seal should be flush to the back side of the plate.

[Andreas Piepke]

Adrian, your bike looks great! Does it run as good as it looks? I can try a seal compound next time. G. Ellis thanks for the advice regarding seal location. I didn't find instruction in the manual. When pushed the seal all the way back, the steel rim of the seal will obstruct the lubrication channel. That's a worry I guess. Do you cut or file a part of the rim away?

Thanks for the advice!

Andreas

[G Ellis]

There is plenty of room for oiling. Do not cut on the seal. Oil will get by on top of seal to the main bearing. I don't thing that anything is wrong with the seal. The seal is just not far enough back.

[Rocket]

I agree with Gary on the seal.  As long as the rubber on the seal is soft and pliable, it should be good.

[Andreas Piepke]

OK, thanks for the input. Now that I've taken the part off I'll put in a new seal anyway. I'll follow your advice.

Thanks for your input

Andreas

[ALB]

I agree with everyone saying do not use NOS seals. They could be stiff, and most are only a single lip seal.
The seals that I provide for the KTM engines are Viton double lip seals and I have to have these made special order because the bearing houses do not stock them.
The double lip also helps as double protection against leakage in case there is wear groove in the crank pin from the old single lip seals.

Alan Buehner

[Patton]

Lots of great information here. Reminds me that I don't know what I don't know.

Did Andreas get the Penton to finally perform to his expectations?

RP

[Andreas Piepke]

Yes, it does run now. Have a look at a short video I recently posted on YouTube:
https://www.youtube.com/watch?v=w9Hzin_caXk
The tank has been painted by now too. I posted some new pictures in a posted called "GS conversion". Post some pictures of your bike and your work on it too!

Andreas

[Patton]

Congratulations!

This 8 pages of technical and troubleshooting data should be a must-read for all Penton "newbies" like me. Gotta have webmaster Dale weigh in and start a best-of-the-best area that novices can tap into and read this type of discussion. I found it in a search for "petcock" as I was looking for a replacement(s)

RP