Restoring a barn-fresh 1966 Sears Allstate

Open heart: open wallet

Puch_head_off_pistonsI pulled the head and barrels to see what damage has been done – alas it is the front piston that seized and the rear piston has evidence of oil film loss and scraping. Interestingly these are on the sides that face each other.

I did some research online and it seems that there are four possible culprits:

  • lean jetting
  • low/no oil in mix
  • air leak (causing localized lean/hot spots)
  • timing

I can pretty much rule out air leak and I’m going to go out on a limb and rule out jetting as I believe it is stock.

A mechanic saw the photos and opined that it is most likely timing. This could be so as I haven’t touched the timing since I got the bike. I did reduce the oil to the minimum setting, as I was using modern oils and assumed I could get away with less smoke. Perhaps at open throttle it needs more.

So, clearly a bore or hone and new pistons are in order. The question is why did it seize. I would like to have some confidence in diagnosing the problem before slapping in a new set of pistons and twisting the throttle again.logo_koenig

Clearly this isn’t a unique experience. I found this photo on the net, clearly toasting pistons is a Puch thing. I was hoping to get away with a hone an a set of rings but, clearly, new pistons are needed. So open heart surgery has led to opening my wallet. Those pistons ain’t cheap.

It seems Elko/Konig is the only game in town for replacement pistons.

To think she was so happy just a few days ago….

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Been a while since this plate was used – shame to cover up the sticker.

I guess expecting reliability from a 49 year-old un-rebuilt engine is unrealistic. I was happy so far as I’ve only addressed cosmetic issues and suspension. My luck has run out.

I was on my way from the licensing office to work on my first “legal” drive. Was doing about 60-65km when I lost power and then the rear wheel locked up. Pulled the clutch and pulled over, the engine turned over but it feels like compression is down, although there is compression. With two cylinders and a shared space it is difficult to tell which cylinder has an issue.

Question now is, full rebuild? Source of the problem? Lean carb, oil delivery – cable or pump? The bike was running great a few days earlier and did the same stretch of road no problem.

This page might come in handy when I get the head off, it shows how to read the piston damage from a seizure.


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Finishing touches

Final push to get the Puch 250SGS on the road.
Certified. Appraisal booked. Tightened the seat springs (which necessitates seat, gas and oil line removal…) Handlebars fitted with better rubber mounting and bars repositioned. Float-bowl heat-shield fabricated out of old coffee-maker stainless.
She’s ready.

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CVMG Paris Rally: 2015

Another Paris Rally, great weather – here’s a few pics of what caught my eye this year.



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Spring in my step

With spring just around the corner, and the annual pilgrimage to the CVMG Paris Rally, I have been working on getting my Puch 250 SGS suspension overhauled. The rubber  seals have long gone brittle and what little oil remains is thick and gooey.

IMG_0003The forks I discovered are bent, not surprising considering the condition of the front fender, the dented fork covers and handlebar into the tank. One is bent more than the other – I will seek out a hydraulic shop to see if they can straighten them out.

I took the shocks and forks apart to assess the condition of the components in case more than consumables are needed. Luckily,  seems all is in order, just dirty, gooey and decomposing or brittle rubber bits. One fork seal was brittle enough to almost cut my hand, the other was fairly supple.

20150218_093335_cThe rear brake lever (part no. 175.4011.2) I ordered from Motor West arrived today, or should I say the envelope arrived. It appears the envelope tore open and the lever fell out.

Packing tape was invented for a reason, Matt. *Update: Matt has graciously offered to send me another at no charge. That’s class.

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