New Guy, 77 GS6 175

[Hank McCurdy]

Hello All: I'm new here, but you may remember my Penton - the 77 GS6 175 sold at a bicycle auction in NY some months ago, and discussed here on the site. Well I'm that bike's owner and I'm hoping that I can lean on you all for some help and guidance in bringing this Penton back to life. The good news is the bike seems very original, straight and complete, so it presents a good starting place for a restoration. The speedo shows about 1800 miles. The bad news is there's not much that doesn't need attention, the worst of which is crankcase corrosion the likes of which I've never seen. I can't believe the volume of junk found. It's pretty bad, but not that deep. Question of the day: does blasting and filling/coating with JB weld make an effective repair? My intention is to make it a sound rider/racer, so reliability is important. Here's a few photos. Thanks in advance for any advice and comments. Hank

[garrettccovington]

I don't have an answer to your corrosion question, but it would really be cool if you could keep the License Plate with the bike and get it registered for the street again.

g

72 six-day

[joe novak]

Hello,  Really nice and complete looking Penton.  For starters, I would suggest to completely remove all the internal components of the engine, and clean the cases and the parts well.   The crank really has some debris on it.   Are you able to remove the crank from the cases?   I believe the cases are Magnesium, so you will want to be careful when working with them.  They are a little brittle, especially with age and corrosion.  Upon further inspection, you will have a better idea which route you will need to follow.  joe

[thrownchain]

I was at the auction. I wanted to talk to ya, but you go out of dodge quick. Some really cool stuff there. Where are you located??
As to the corrosion issue, you might want to see if you can find good cases to start with, then build from there.
Also, welcome to the group, you won't find a nicer, more giving group of people than you will here. You need anything, just ask, from info to parts, you've come to the right place..

[VICTOR MONZ]

I rebuilt a couple 73 Penton 250's and 72/73 175's with the KTM crankcases looking familiar...I ended up buying a few motors to get what I needed.  I stayed away from the JB weld...kinda like solid cases, others swear the JB will work fine..lot depends on what your intended use is...competitive racing or trail riding and if you don't mind a little oils leaks and of course all depends on $$$$$.

Just my 2 cents.

Victor

[tomale]

Hank welcome to Pentonia, yes more than likely the cases are Magnesium, Magnesium and water do not mix well. It usually looks worse than it is. Still taking the motor completely apart and checking everything is a very good idea. Give a look at the supplier list. You should be able to find what you need. A good manual is the place to start if you do not have one already.. Give AL. B a call he can fix you up. The Rear brake stay looks like it is hand built. maybe not but it I do not think it is the stock one. it looks nothing like the stock one.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)

[Britt Boyette]

That rear stay might not be stock but it sure is beefy. Rocks beware!

Britt Boyette
1976 125 MC5
1975 250 HS

[TGTech]

Hank,

I would contact Chicago Jerry because he is working on a lot of KTM engines and I've seen some coating that he used on some cases. Here's Jerry's e-mail: [email protected].

Dane

[thrownchain]

In case anyone is wondering, the first 2 pics is how it was sold at the auction, grass and all.

[chicagojerry]

hi hank. (and thanks dane for the vote of confidence) its hard to tell from your pictures how bad the crankcase area is really deteriorated.yours trans area looked good tho. once you get it all cleaned up. try taking some more pictures and sending it to me. if the pitting is not that deep as you stated, they may be salvageable. i have had very good success rescuing motors from getting scrapped out.  but its especially critical around the gasket area.  the epoxy i use is marine-tex grey.  i have tried many different epoxies in different applications but this is the best for this style of repair. some times it takes a couple of coats with the possibility of the gasket surface needing to be
faced-off/machined. after i make the epoxy repair, i paint the crankcase area with glyptol paint. as an added precaution, in addition to the centercase gasket, i coat both sides of the gasket with a anaerobic sealer. that will take up more of any imperfections. are you going to the potomac vintage riders swap-meet? i could look at them there if you are.  good luck, that motor will come back to life in that beauty.  chi jer
[email protected]

[Hank McCurdy]

Guys,
Thanks for all the response - I knew I was in good company. I got this Penton from the guy who bought it at auction, but besides missing some of the accumulated hay, it hasn't really been touched til I started on it last week. The plate and registration are from NY 1978. I'm in SE PA (near Valley Forge)and know it's fairly easy in PA to get an antique tag - one lifetime registration and no inspections. But I'm not sure if that will work for dual sports and enduros. The brake stay looks professionally made on a mill, kinda like the Carl Cranke version. Back to the engine - it's now apart and partly cleaned up - I made the tool to press the crank out from the clutch side and it came apart easily (let me know if anyone can use this little press.) The crank and bearings look amazingly decent and being on a strict budget, I'm tempted to use them, but will decide later. I did talk to Al and know what's available. Anyway, my plan is to blast the mag side crankcase area today after work and see what it looks like. There's a spot on the low mating surface where it close to the edge, so I've got my fingers crossed. I'll get the clutch side later. Jerry: I would like to learn more about the repair, and will post a picture or two as soon as I get the chance. Thanks again for the help and interest. Hank

[joe novak]

Jerry,  I have a Sachs engine with the mag/sprocket area broken (what else is new?).  Would the marine-tex grey epoxy work in an area like that?  Where can I purchase that specific marine-tex grey epoxy?   You know I live locally, so I could shop locally....  Thank you,  Joe

[TGTech]

Joe,

I've just welded up a mag side of the case for Doug Wilford. The case and cover were had holes in them and I "fixed" it.

Dane

[Rocket]

Hank
I sent you an email through the system but maybe it is not working yet.  I have a 175 bottom end that I built up last year, ready to go if you are interested.
Rocket

[tofriedel]

Hank, I have done a couple of case sets with mag rot, using epoxy with good success.  Both times they were in worse condition than what is visable in your cases.  The rot has always been confined to the crank and the ignition area.  Clutch side and tranny area have always been clean, but that have always had oil in them.

ChicagoJerry knows what he is doing, let him look at them at the swap meet.

Tony