New Hobby

[Mully]

Ok, the bug has bitten me.  I am in the process of finding a restoration project.  The one I am looking at currently belongs to someone who really doesn't know what they have, as well as myself.  So if I may, I have a question (or two, or nine) regarding serial numbers.

51 31270344  is this a valid serial number for a 1974 Penton 250.
This serial number is on the frame.  Is there another serial number located anywhere else??

Thank you,

Mully

[Larry Perkins]

Mully,

Welcome!  The motor number is located on the right case just below the cylinder.  That may not have been the original frame for the motor if it is a 250.  That frame number would generally have a 125 or 175 in it.

Larry P

[tofriedel]

Mully,

Frame number doesn't sound correct.  You may have to look closer at the number that is stamped into the stem.  At times with paint, rust, etc. the number is difficult to read. The 1st 2 digits are probable 54 instead of 51.  The digits 312 indicated the year and month the frame was built, i.e. Dec. 1973, which would make it a 1974 model.

There is an engine serial # that is located forward on the right crankcase half, just under the cylinder.  It should have 8 or 9 numerals, with the 1st digit indicating the year, at least through 1979, and the next 2 digits indicating the engine size.  The number 4 would indicate the engine was built in 1974 and the next 2 digits should be 54 if it is a 250cc.  Yours will probably read 3-54xxxxx.

Tony

[rob w]

Tony,

Yes, there was a common (but not real common) production code prefix number "51" before the year and month numbers. I know I've had one, and in the production code area, it shows one bike with a 51 prefix that was produced only 5 bikes behind this one that Mully is looking at.

Bob W

Oh, and hello and welcome Mully, great hearing from you. Good luck, it's a wonderful new hobby you've chosen.

[thrownchain]

Welcome to the "group", you have come to the right place for info.
It's a good idea to find out all you can about any purchases you may want to make. Gives you a better idea what you're getting into, and availability of parts. Personally I've stuck to 125's, but everyone has his own "vice".   Good Luck

[Mully]

I have poored over this website and think I have this one figured out.

Frame#  51 31270344

using this bit of information:
The second type consists of the same 8 digits but also has an extra 7-, 51-, or 54- ahead of the original 8 digits. These extra digits could be called production codes for the lack of anything else to call them. These digits were only found on the KTM powered models. If the 7- appears, you are looking at an all-new Jackpiner model starting with June 1972 through June 1973. The 51- and 54- seem to start where the 7- number ends which is June 1973 through September 1976.  To find the year, month, and serial number, you simply disregard the 7-, 51- or 54- and look solely at the last 8 digits. For example, 7-20655454 would be a model built in June 1972, with the remaining digits again being the actual serial number.

I would be correct in saying the frame was produced in December of 73.

Engine number:  3 5402375

using this bit of information:
After working with these frame numbers, I thought it might be fun to do some research into KTM engine numbers. With some 75 engine numbers to work with, I separated them into 3 categories: Type 52 which is the 175cc, Type 54 which is the 250cc and Type 55 which is the 400cc. However, I did not have any Type 51 125cc numbers available. What I learned was that putting each type in ascending serial number order showed that each size engine serial number started back at 00000 and went forward, unlike the frame numbers and all its models that ran consecutively year after year.

I would be correct in saying engine was made in 73, and it is a 250.

So, using the information from the site it is pretty safe to say the bike I am looking at is indeed (frame and motor wise) a 74 250 ??

If the above is correct, are there any other pointers you fellas can bestowe upon me regarding what to look for...........

Mully