JP Super Mk5 17 inch

I thought I'd share with you my recent acquisition of a JP Super Mk5.

It came from an old lawnmower service center which I was told closed down some 40 years ago.

It had a seized cylinder and an engine with no compression whatsoever, to be honest I only bought it for the engine as a spare for my Dennis Swift, totally covered in surface rust and what looked like matt black spray paint (more on this later).

I began stripping the mower down after giving every nut, bolt and mating surface a spray with GT85, I looked into the fuel tank and found it contained old fuel which I think had successfully turned back to crude oil, after a 24 hour soak in paint thinner it eventually came out and after plugging the holes and filling the tank half full with gravel and water I spent an hour shaking it with great results as it came out clean.

the carb got a little attention next and after finding it clean I turned to the lack of compression, removing the cylinder head my suspicion of a stuck valve was right as the exhaust valve was stuck solid, I got it free of sorts and turned to the ignition as there was also no spark, cleaning the points soon got a health spark so next step was fuelling and give the engine a chance and would you believe it? It started and ran silky smooth second pull! After about three minutes it got loud and dusty, I then realised the silencer had rotted through and blown the fiberglass packing everywhere.

Happy the engine was good the whole machine was stripped to every last nut and bolt and cleaned, oiled, greased and re assembled. Each nut and bolt was cleaned on the wire wheel and then blued using heat and oil to give them a weather resistance, the front rollers were placed in the lathe and the dirt sanded out as all three had no rot and were in great condition then coated in boiled linseed and left to dry.

a new exhaust silencer was built with the same configuration as the original and re packed with the original fiberglass which I picked up and saved, I dove deep into the carb and found the float had a crack and swelled up sticking it in the float chamber so that had to be replaced and it got a nice new gasket too.

I said earlier about the matt black spray paint type stuff on every sirface? Well it wouldn't come off with anything except GT85 and fine scotch brite, I noticed there was some bubbling on the original control  cable outers, as if it had got hot! Somehow I'm coming to the conclusion  this machine may have been rescued from or survived a fire at some time and I think it was covered in soot residue! Another clue is I found an Amal carburettor behind the cutting mechanism with a melted float bowl.

I replaced the throttle cable completely but I saved the original outers to the clutch and roller brake as they are the rubber and canvass covered type and where on earth are you going to get those? The inners were donated new from Vespa and two of the original barrel ends re soldered to the ends of the Vespa clutch cables to make replacement cables.

The cutting mechanism was disassembled and a long tedious task of removing any corrosion from the cutting faces of the cylinder began, I watched my old dad hand sharpen a push mower years ago and picked that up from him! The cylinder would benefit from a regrind at some time and a new bed knife would be nice as it has been reversed sometime in its life but as it stands it cuts paper at every section so I'm happy with that. 

After getting the old girl back together and cleaned up without going down the restoration route, I'm not a fan of show room restoration,  my philosophy is it took years to look like it does and if I can preserve it I will instead of killing its character. I fuelled her up and went for a start, I'm pleased to say she now runs nice and the silencer is as quiet as the original and she cuts beautifully,  there's a couple of little points I need to address but there she is, back in running codition.