Thanks for disagreeing, because it makes me think I should nail down the info concerning fitment type. I aim to. The fact that both mains inners are sliding on crank does beg the question, somewhat, too BUT, I expect John Wright to know what to expect when fitting the bearings, as I believe but am not 100% sure, he has fitted these more than once to the Desmo. When I ask should it be 'firm-push' to fit, I mean exactly that. JohnW. seems to indicate, yes. I'll check that here, upon disassembly. On the other hand, these desmo bearings are pre-loaded. I have seen inners on good cranks with preloaded bearings slide easily. The preload as per manual is given as 0.2 mm on cases without a gasket, and 0.15mm for cases with a gasket. The preload on this engine needs checking and may need increasing. We'll see. PS. EDIT; further reply above by JOhnW. has just arrived as I posted this.
Update: I'm not the best engine builder when it comes to keeping my eye glasses smudge free! I took another look, as per Bumpstart's suggestion, and yes he is right. The inner appears to be spinning correctly, and the ball race holder is what I had been observing to spin at slower speed. There is little room to view overall peering through the gap with sight of bearings covered by the crank, and I hadn't seen these bearings before, their colour and dimensions. An easy mistake to make, especially squinting. Forgive me. I feel relieved and hopeful. I'll be setting the preload appropriately, noting that it's different (preload reduces in use?) for used bearings.
Hi Mine was a 900 and removal of the primary gear was done so I could strip everything out and clean up the cases properly prior to paint. You could probably get away with leaving everything in the right case but I don’t know for sure, for what it is I’d take it all out, don’t forget about oil pressure relief valve, gear selector detent and neutral switch prior to splitting Here’s a couple of photos of the main bearings the darker centre part is the ballrace holder Keep us posted
Right on, the darker race ball holder is what I had at first mistakenly observed as the inner bearing. You've definitely earned the badge of 'wicked dilligent, observant engine rebuilder'; I wonder, as a new member where you came from?
Been a member for a few years now but as I don’t really post much I seem to be reset as a new member The SS is probably a recent acquisition as I’ve only had it 17 years
Just a thought if you decide to change the mains for some reason, get them from ducati as the internal angle is different from commercially available bearings Preload checking on a 996
You are right, but I was having a senior moment ! Good that you cleared up that the inner bearing race is not spinning on the crank.
OK just a teenager , but definitely headed somewhere. Possibly due to 'Signore' John Wright's fatherly supervision!
In my experience, the mains are the only bearing that are not easily obtained from anywhere, OTHER than Ducati. All the others are easily obtained SKF. If you do decide to replace all the case bearings budget on about 200 quid
Useful to know that in advance. Ta. Some Thoughts based upon present observations: ................................................................................ - Bearings seem good. So do the gear teeth profiles. - I notice that idler starter gear has been removed and re-assembled, and so I ask myself why then, if not to split cases? - The alternator nut has been off (to fit a 600ss flyheel for sure). - Flywheel where reduced in depth, retains a burr; never the practice of one properly taught. - At this time, the gallery plug backing out is the main concern. [ Note: JE High compression pistons, standard size, lightly honed to suit, and improved black barrel studs are fitted]. I'm puzzled by the owner fitting such performance mods and not noticing the gallery plug coming out, lets say 10,00 or maybe less miles earlier; odd that it should be backing out now, with as yet minimal wear to it, when I come to it fresh. POssibly its use at high comp hastened gallery plug backout, due to increased heat. Possibly a new aluminium gallery plug had been fitted, and wasn't locktited in. Bearings may have been replaced in its estimated 30,000 miles. To DO ........... - I may do well to open the big end bearings as a matter of course, to examine them, with new bolts at hand. That is, although they seem nicely fitting and smooth, in order to get a good visual of state of use/wear overall. - Examine oil pump for wear. - Check crank end float and configure thrust washers for all important pre-load. - Refit with new, gallery plug; loctite and peen for fastness. - Measure for Squish upon assembly, so configure base gasket thickness to adjust squish. - if possible, take burrette reading to gain accurate idea of actual compression. - Remove flywheel burr - Marvel at the engineering.
