- Joined
- Jan 27, 2015
- Messages
- 64
After a couple of months of traveling and dealing with demands of work, I have finally been able to get back into completing the rebuild of my 2013 CR. Progress is happening albeit slowly - I can only spend a couple of hours a day at a time, so I take on tasks that can be accomplished within that time. This motor is super easy to work on, a real joy to undertake this work myself. I have built countless Norton and Triumph motors in the past, this is really no different.
Day 1 - installed the new main bearings, completed the final parts clean, removed all gasket material. Mounted the crankshaft into the RH case - bolted up the centre mounting plate - I had recessed the threads about 1/8" of inch so the bolts would not bottom out this time. Used bearing mount 620 at the peg locations to fill in any enlongation caused by the plate being loose. Installed the balance shaft in the LH case. Applied ultra-grey sealer to the case and installed on the RH case - bolted up and torqued to spec.
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As usual, back in the office, I decided I would read the Norton Manual in advance of embarking on the next steps the next evening. I noticed in the manual there is a note in red about - "DO NOT FORGET THE SPACER ON THE BALANCE SHAFT"... well I had not installed a spacer. A bit of panic. Checked the bench and all the boxes of parts, under the bike, on the stand - no spacer. I checked the later EURO4 manual and the same parts diagram does not show a spacer - interesting, but later on in the EURO4 manual the same diagram as before with the red note. Hmmm. A quick email to Mr. Coote Senior in Ontario who confirmed that my bikes has the later forged balance shaft and therefore no spacer. Nice of Norton to clarify this in their manuals. Anyway - I could progress again.
Day 2 - installed the gearbox, primary gears and clutch. Cleaned and mounted the pistons to the rods, installed the cylinder barrels. Compared to other parallel twins (Commando), the 270 deg crank with the offset pistons allowed the cylinders to practically fall onto the pistons, no ring compressors needed.
Day 3 - installed the timing gears and chain, same method as older Commando's - count the links, in this case 15 1/2 link. My bike has the timing marks on the case and it was a very simple job to install along with the tensioner blocks. Timing cover installed, Oil pump installed and oil lines connected. I added oil into the sump at this point. Next installed the cylinder head and torqued up the bolts in sequence - several times. I will give it another re-torque before I add the rockers.
Side bar on the rocker shafts:
The rocker and top end oiling system that Norton have designed is pretty ingenious, but there are some issues starting to develop. My exhaust rocker spindles were seized on the shaft. Clearly a lack of oil. My fix is to ream them (flex hone) and hand machine spiral oil ways on the bushes. A supplier in the Netherlands is offering a fix which includes new bushes made from high-performance material - as apparently a number of 961's have suffered from failed bushes. Maybe something to keep in the back of your mind for down the road when things get noisy.
The oil system feeds oil under pressure up each push-rod from the hydraulic lifters. The push-rods are hollow with an oil way the full length. The top ball end engages in the adjuster which in turn is hollow that allows the oil to flow into the rocker arm through a tiny orifice. Once in the rocker arm it feeds the rocker spindle through a centre grove and then flows out to the roller end of the rocker shaft to oil the valves. It would seem that because it is a flow through system, that there is no pressure to lube the tight shaft bush. I will have to be careful about the depth of the spiral grooves so as to not starve the roller end and the valve.
It all seems very complicated and I wonder about longevity with the potential of crap to get caught in the tiny oil ways and cause damage. A good reason to make sure all filters and oil is changed regularly and NEVER use RTV
Day 1 - installed the new main bearings, completed the final parts clean, removed all gasket material. Mounted the crankshaft into the RH case - bolted up the centre mounting plate - I had recessed the threads about 1/8" of inch so the bolts would not bottom out this time. Used bearing mount 620 at the peg locations to fill in any enlongation caused by the plate being loose. Installed the balance shaft in the LH case. Applied ultra-grey sealer to the case and installed on the RH case - bolted up and torqued to spec.
As usual, back in the office, I decided I would read the Norton Manual in advance of embarking on the next steps the next evening. I noticed in the manual there is a note in red about - "DO NOT FORGET THE SPACER ON THE BALANCE SHAFT"... well I had not installed a spacer. A bit of panic. Checked the bench and all the boxes of parts, under the bike, on the stand - no spacer. I checked the later EURO4 manual and the same parts diagram does not show a spacer - interesting, but later on in the EURO4 manual the same diagram as before with the red note. Hmmm. A quick email to Mr. Coote Senior in Ontario who confirmed that my bikes has the later forged balance shaft and therefore no spacer. Nice of Norton to clarify this in their manuals. Anyway - I could progress again.
Day 2 - installed the gearbox, primary gears and clutch. Cleaned and mounted the pistons to the rods, installed the cylinder barrels. Compared to other parallel twins (Commando), the 270 deg crank with the offset pistons allowed the cylinders to practically fall onto the pistons, no ring compressors needed.
Day 3 - installed the timing gears and chain, same method as older Commando's - count the links, in this case 15 1/2 link. My bike has the timing marks on the case and it was a very simple job to install along with the tensioner blocks. Timing cover installed, Oil pump installed and oil lines connected. I added oil into the sump at this point. Next installed the cylinder head and torqued up the bolts in sequence - several times. I will give it another re-torque before I add the rockers.
Side bar on the rocker shafts:
The rocker and top end oiling system that Norton have designed is pretty ingenious, but there are some issues starting to develop. My exhaust rocker spindles were seized on the shaft. Clearly a lack of oil. My fix is to ream them (flex hone) and hand machine spiral oil ways on the bushes. A supplier in the Netherlands is offering a fix which includes new bushes made from high-performance material - as apparently a number of 961's have suffered from failed bushes. Maybe something to keep in the back of your mind for down the road when things get noisy.
The oil system feeds oil under pressure up each push-rod from the hydraulic lifters. The push-rods are hollow with an oil way the full length. The top ball end engages in the adjuster which in turn is hollow that allows the oil to flow into the rocker arm through a tiny orifice. Once in the rocker arm it feeds the rocker spindle through a centre grove and then flows out to the roller end of the rocker shaft to oil the valves. It would seem that because it is a flow through system, that there is no pressure to lube the tight shaft bush. I will have to be careful about the depth of the spiral grooves so as to not starve the roller end and the valve.
It all seems very complicated and I wonder about longevity with the potential of crap to get caught in the tiny oil ways and cause damage. A good reason to make sure all filters and oil is changed regularly and NEVER use RTV
