Replacement motor for my shovel...

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Prof
Founder, Choppers Australia
Posts: 5622
Joined: Sat Oct 22, 2005 3:54 pm
Location: Willunga, South Australia
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Replacement motor for my shovel...

Post by Prof » Wed Aug 16, 2017 9:55 pm

My faithful ol shovel that has done over 200,000 miles (300.000km). Untouched bottom end and clutch. When I replaced head gaskets recently, I found that the front gudgeon pin was wearing a groove in the cylinder wall, so I put her aside and had a grand time riding around on Paul's 550 (see Batman post) for a few weeks.

Then Jason dropped by and said his holidays were boring... could he come up and swap out my motor. Sounded like a plan, so he dropped in over the next three days and did the swap.

Here's the replacement motor. I got it some years ago as a part of another purchase. It was an excellent price as it had been sitting for fifteen years or more and the owner had no idea of its status...
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We pulled out the plugs and poked a camera in to see what the cylinders were like. Fresh cross hatching meant at least a hone if not a rebore, so presumably at least it had new rings and hopefully a valve grind. It was too much trouble to do a compression test, so we figured we'd take a chance. Nice thing with these early shovel motors is that the heads and barrels can be dismantled very quickly and with the motor in the frame. How good the bottom end was was anybody's guess, but it would be a fool who would redo the top end if the bottom was no good... but then again there are fools about! Also we didn't know how much corrosion might have set in over the years.

The two of us lifted out the motor (although I have done it a few times by myself). Surprisingly, the shovel motor is lighter than a CB750 and easier to get hold of. Jason was having a good time and as usual was laughing and smiling during the whole process...
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The last day, Jason was coming up, I received a rather worried call from the poor bloke. He had just pulled up at McLaren Vale with a horrible noise in the primary case of his S&S chopper. Paul and I hightailed it down in Paul's effy and loaded it up. I ran the truck up the embankment to straighten out the bike ramp as his machine is fairly low...
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Front nut had come loose and everything was wobbling around. We got it all tightened up and after putting Humpty together again Jason got back onto my shovel...
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Around midday, the ragged sound of a big twin rattled the workshop. Rayne rolled in on his S&S Panhead chopper (foreground). He was on his way back from a couple of days on Kangaroo Island and reported a fantastic 'must go again" time. Only downside, besides having to come back to work was that his bottle of rum was pinched out of his luggage on the trip over...
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I normally run an evo CV carb on my shovel, but Jason convinced me to try the flat slide Mikuni off his previous RevTech motor. The bike started instantly and ran fine... but it is a big carby and I would have to find a different aircleaner and make up a more appropriate choke, so reluctantly went back to my CV. The motor ran fine with this as well. By the end of the day (Jason's last) just a few bits needed finishing on the new installation. I finished these off the next day and got in a couple of short rides in to gently ease in the refreshed motor.

Recent customer, Andrew rocked up on his shovel FLH to chase up a pile of parts and Dave who's been helping out around the workshop for 12 years also came by. We built his Sporty chopper some years back and now he is building a Yamaha/BSA/Harley in my workshop and had come to pay a bit of progress moula. I can go a few days without visitors and then up with three or four overlapping so never a dull moment...
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The replacement motor is also an 80 cuber, but does not have the pickup of my previous motor which had been over bored and had a bit hotter cam. It has a bit of tappet noise if you listen carefully (mine had absolutely none), but it is smooth and starts easily and still pulls pretty much like an 80 cube shovel should. Compression is low; 110 psi opposed to 150 psi on the other motor. It doesn't seem to use oil or smoke, so I will pull the heads off and have a look at the valves down the track.

Meanwhile I'll enjoy getting the miles up on this one...
Chopit'nrideit... Prof

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