SST 250 rebuild

[chopper]

So as im now getting along with the rebuild i better start a thread showing you nosy lot how it started and its progress


Its a 76 SST250 2 owners from new, last owner since 1978 and hasnt run or been on the road since 1980, bought as a complete roller with a seized engine

How it started!

[chopper]

After 3 days!

[chopper]

Frame and swingarm freshly powder coated

[chopper]

Forks - Stanchions were badly rusted and pitted so dropped them at ABE in greenwich and they re-chromed and ground them, forks rebuilt with 5wt fork oil, new oil seals. Forks legs painted black while they were stripped.

Wheels - were badly corroded, rims were long past it hubs were covered in surface corrosion, rims and spokes cut out and dumped, hubs blasted



and enamelled black along with the rear drum






couldnt help myself with the rear sprocket

[chopper]

Yokes were sanded, primed and painted a metallic silver as the surface wasnt up to polishing IMO



All of the switchgear, bars and other small parts just needed a clean up with a wire brush on a drill and a lick of paint.

[chopper]

Back as a roller again with the bottom end of the motor dropped in

[banquo]

Good progress Neil - you don't hang about, do you?

Have you had the bottom end down?

[chopper]

My major issue has always been with the motor, the piston rings had rusted into the chrome bore of the barrel and trashed the bore, there were a couple of broken fins already but i managed to trash a few more when forcing the piston out! so the barrel is IMO past it. So the search began for a replacement barrel and piston, not the easiest thing to find i soon found out! I have managed to get hold of a later Cagiva SS250 barrel and piston which apparently works but as yet I have no guarantees and as my knowledge of the inside of two strokes is limited at the moment im not sure what to do.

The Piston is the same in every way as is the dimensions of the barrel, the head stud pattern is completely different as is the intake and exhaust ports, the fins are also an inch or so wider on either side but i could easily trim these down if need be
I can make or get made adapters for both im sure but im concerned that the thing will ever run once its back together and the barrel and piston i bought were far from a bargain!

I have looked into a complete replacement engine as there are 5 or 6 european brands that share exactly the same engine mounts apparenty but it would be nice to keep the motor as original as possible


Old Barrel



New barrel



Old intake



New intake

[chopper]

Originally Posted by banquo

Good progress Neil - you don't hang about, do you?

Have you had the bottom end down?

dont do waiting

its been very straightforward so far but i get the feeling i may slow down from this point on!


Didnt split the cases no, crank seems fine with no play and turns freely and have been told by the couple of experts i have spoken to that they are good and strong so have left it for now.

[chopper]

All the tins went off to paint to a friend of mine that runs a car repair shop a couple of weeks ago and are being treated to a blast first, all were pretty rusty but in good condition, im going red as below



they are apparently being a pain and have taken multiple coats of high build filler primer to get a good flat surface to paint on, the tank is in need of re-sealing as it is leaking badly apparently, some repairs have been done but i will petseal it when they all come back




graphics copied and being made ready for the finished paint in a couple of weeks