Another winter rebuild

I wont be giving you another blow for blow break down and rebuild this time. There just isn't the need, you know it already.

I will however let you know about any changes of points of interest along the way so here we go and no doubt waffle a fair bit as usual.

The bikes strip down was carried out quickly to get the engine out and have a good look in there.
The bike had been loosing power towards the end of its last few races (well I had noticed this happening now anyway) so I was curious as to why.
A low oil level hinted that the engine might have been running hot due to low gear oil.
Everything looked fine inside and the pistons didn't look like they had seen much use at all and certainly not a whole season. With the barrels off I gave the crank an in situ inspection for big end lateral and axial play which was as new. As such I was happy with the condition of the engine and ready to slap it all back together.
A new set of pistons, rings and little end bearings were ordered from Grampians previously so I could get the engine rebuilt quickly. Naturally I ordered the wrong bearings however so had a wait to get it back together.
When they did show up (and I finished buggering about with the new CBR400RR-L NC29) The engine was quickly rebuilt with the new copper base gaskets I had bought at the beginning of the 2019 season and linished the old head gaskets for reuse. The engine was built and torqued on the bench then the heads were taken off again when I remembered you can't get the engine in and out with them on. Dummy.
With the engine in the chassis the chain and sprocket were refitted but the "problematic" front sprocket nut turned out was actually heavily worn and it wasn't just me not doing the thing up tight enough.
A new nut was sourced from the old faithful, source of eBay along with another tab washer (which is for the spares box) and slunk on the bike once it had arrived.

Next up I tackled the exhaust manifold.
I have wanted to do this for ages. The one I have is borrowed from Andy (as you can see on the rigt). It comprises of header clamp plates with a cut off section of down tube which has been made into a cone shape (very roughly) so the expansion chambers just slide over the top.
I decided to make some of my own with some tube and a couple of my exhaust clamp plates I had bought a while back.
As I couldn't get any tube of the correct OD: I instead used some sheet steel which I shaped round some bar and seem welded it. This was then chopped in half, tidied a bit and then welded to the plates. This is a much more snug fit that the old manifolds and the shape is more consistent which should (hopefully) make for a better gas flow.

I also fabricated a tab which I welded onto the top of the manifold so I have somewhere to secure the spring to which wouldn't foul the frame like the old ones did, snapping the springs after every other race meeting.
These bolted up nicely to the engine (yup had to remove the front mount to get them over the studs, nothing is easy on this bike) with a bead of copper gasket on the inner mating surface.
The TZ expansion chambers fit up quite nicely with only a little argument about lining up but not as bad as I had imagined (the angle of TZ exhaust manifolds and RD are quite different) and the rear rubber mounts took up the slack anyway with the help of the back up wire locking.

With that all done it was a simple case of reassembly. I will probably do some more before next season but, if all goes wrong, I could jump on the bike and race it as it is. It's not a bad looking bike really.
As it turned out, it wasn't till July that the bike would be dragged back out again.
In that time I was busy with other projects but I still found some time to tidy up the fuel tanks paint and give it another much needed run.