Winter project....Vespa Sprint VLB

I’ll have you know myMonkey has a clean bottom

 

As this is a hobby bike and doesn't exactly benefit the current Mrs Monkey I'm mindful of budget...
So when it was all stripped down and I found the crank was knackered as well as the cush drive it was somewhat disappointing!
However if I was replacing the crank it would have been rude not to upgrade the exhaust...and lengthen the gearing a bit, and uprate the rings
That's a little bit of big end shim...


...that allowed the conrod to flap around and the big end pin to displace.


The cush drive, a damper effectively that softens the gear changes, is supposed to be dampened by complete springs


And this is the cruciform. This cross slides up and down the output shaft and engages with the gears as you shift the grip...slightly worn

 

Some of the goodies hidden amongst the boring old bearings, seals, gaskets, and gearbox bits


Believe it or not that box exhaust is actually an expansion pipe designed to look standard

 

Gasket making...a soothing pastime if you need to err pass the time


Cush drive repair. That's the primary drive gear that drives the layshaft and is in turn driven by a gear on the clutch driven by the crank...


This one has an extra tooth to lengthen the gearing a tad

 

Output shaft and building the gear stack


Half the case built and ready to close

 

Which I did. Then got impatient. I know better but...couldn't wait and took it out. All was well for 300 yards until I gave it full throttle and seized it!
100 miles to bed in new rings... pah

 

Anyone would have done the same.

 

Not deeply scored. Those of you who ride 2 strokes will be familiar with going everywhere with the left fingers covering the clutch waiting for the screech of ally melting into iron


So I made what I should have made earlier. Butchered a sphigmomanometer...easy for me to say only one gin in


Block up the inlet and exhaust, screw in the plug and pump to 6 psi, spray with soap and chase the leaks.
Had a huge leak on the carb box

 

Sorted that then on to jetting the carb


This is the jet overlap on the Dell'Orto SI carb.
Interesting isn't it...and a head mess. All jets overlap depending on throttle input and woe betide if you get it wrong on the deceleration side of the tune

 

Sito exhaust?

 

And that's where we are. We are caring for Mum and Dad for a few weeks whilst Mum recovers from a knee opp so I'm thrashing about the Lincs lanes for an hour a day doing plug chops...
Transport for transport


And a lovely ride out to Wickenby airfield. 12 Squadron base for a while. Interesting history.


And finally. Messing about out of the rain this evening with an original 60s rack I scored for a song from eBay that will carry a tent and bits and bobs for the odd summer get away.


So far so good....

 

SIP Road 2. Old design now but dependable and still relevant.

 

I killed it again, so rebuilt it!

VMC Super G 177 top end now, bigger carb and a more careful approach to runnimg in. So getting some miles on before I open it up.

Jaunty ride up into the Manifold Valley this afternoon...