Make sure thrust washers face in with the dimples.

Thanks Bondy, good tip.

The dimples hold the oil so the big end bearing gets lubricant.

...

 

Some damage by the kick start mechanism

 

...

 

The middle gear on the left axle seems to have to much play.

 

...

 

 

The vid is nice I thing the third bearing had some debris inside.

 

Anyway I would try to replace damaged engine parts, especially to the kickstarter and to the gearbox, a broken gear can cause some damage.  (I would replace whenever possible the pair of gears).

 

I had some really in depth going issues with gears and kickstarter mechanism which ended a big rebuild.

As noted in a previous post stating "only 500 159's were built making it relatively rare" is incorrect. I know this as I owned at one time serial 4703 and a good friend has 4698. They made thousands of 159's.

Steve

Now isn't that lovely, they stamped a little hart in the case.

 

 

Cylinder and head ready for painting, which in the meantime has been done. The cylinder is at the shop for a re bore and the crank shaft for a new con rod.

 

Lovly job

Although I thought that the free spinning gear on the layshaft had too much play, it wasn't as bad as I thought.

Thanks to InMotion I got a  brand new, about 40 year old     shaft and gear.

Thanks to a manual, and the simple lay out of the Bultaco engine, the rebuild is coming along nicely. Crank and cylinder are expected back from the shop any day now...

 

 

 

 

Home made engine support:

 

Edited January 7, 201610 yr by guys

Just bought me an original 1975 style aluminium petrol tank for my Sherpa. In the south of England of all places.

 

It's to replace the slimmer 199 type plastic petrol tank that was on my bike when I bought it.

 

Great!

 

 

 

 

All's well that ends well.

 

 

Heating up the engine case to insert the crankshaft:

 

Putting Loctite 510 on the gasket, just to be sure.

 

 

The work on the engine is done and it's back in the frame:

 

Before:

 

After:

 

Very pleased with the result. Money well spend if you ask me 

 

 

Sounds "perfecto" !!!

 

Good work.

Edited February 17, 201610 yr by greeves

Good work Guy , it doesn't get much nicer sounding than that!!

Best regards

Larry

Edited February 19, 201610 yr by lbhbul

Fascinating read and education thank you all.

My 191 has perhaps a Mahle piston, assistance in identity will be welcomed, at 84.75mm size. Some scuffing and broken lower ring. 20mm diameter gudgeon pin retained by circlips, and 2 alloy spacers.

InMotion stock  84.70 ring sets, and I have asked them if they will fit. Hope so, as do not wish to buy complete new piston at this stage in the rebuild. 

So, what piston do I have, it looks like "guys" in earlier post this thread, and if new required, what do you suggest with 84.75mm bore?

And should bottom of barrelled be chamfered to aid piston with rings insertion?

Many thanks, jj