The ‘first’ 70,000+ km.
Winter 2021/22 and no home renos or friends’ bikes to rebuild(ish). Just over 105,000km. on the clock of the CBX, a motor that sees redline on a fairly frequent basis I might add. I was certain that the original cam chains needed replacement and was curious about the condition of the original crank & con rod bearings as well. Seems a no-brainer…hold my beer, I’m goin’ in
You might recollect this motor got a rebuild a little more than 70,000km. ago.
I thought I might share some of the more noteworthy observations that presented themselves along the way.
Here we go…
These boots were brand new and from a reputable supplier. I had been noticing mild ‘sweating’ where they mounted to the head, and that even with stepless screw clamps. They had dried out to the point of being unsalvageable after being removed.
When removing the alternator, I discovered that the small aluminum plug installed in the end of the primary shaft had become adrift at some point. It was loose in the small cavity between the alt. clutch plates and just fell out when the alt. came off! Among other things, it directs a fine stream of oil at the alt. clutch plates. The results were sadly predictable. Curiously, my voltmeter never indicated any charging issues even last fall when I was using my heated grips & vest.
Gave the cams a quick polish, super shape! Nothing untoward going on with their journals either. The Oldham couplings will see replacement with a pair of oversized items from Bert @ Six Center.
Cam & primary chain guides showing multiple cracks of considerable depth and dried condition.
This tensioner (cam chain ‘B’) was a brand new OEM bit 70k ago. Think our motors develop much heat!? I replaced the rubber cover that damps movement caused by the spring’s natural resonance. Fun fact: I noticed the rod that interfaces with the tensioner locking bolt is machined as a wedge with the thicker part facing the tensioner. The locking bolt only has to be snug against it, NOT over-torqued, to arrest it’s movement. Good to know, no
I often read of folks asking after the quality of Cruzinimage piston kits. Here’s one of my big-bore slugs, check out its condition. One picture…
The bearing surface of the starter one-way clutch showing multiple scoring. These surfaces have to be pristine to ensure proper engagement of the three locking rollers. Spent a fair amount of time polishing the imperfections out.
Let’s talk trannies…quick vid illustrating advanced wear on the splines of the countershaft where the sprocket mounts. Check out the difference with the second, replacement, shaft in the video
https://m.youtube.com/shorts/7345QC8_Z9M
BIG surprise with the condition of the teeth on the fifth gear cog on the mainshaft! Curiously, the teeth of its mate on the countershaft were fine.
Folks seem to replace the cloth-covered oil cooler hoses on a regular basis but I don’t recollect any mention of the similar, if smaller, feed line from the upper crankcase to the head, behind the cylinders. It always gave me pause. Fabbed a braided line and put the issue to rest
I also figured that as long as the lump was in pieces I would hit up the plot with a ‘refresher’ coat of colour. Pleased with the result.
In the end, all of the crank & rod bearings required replacement. All journals got polished and OEM bearings were installed. Fun fact: I shopped around and saved BIG by ordering through
https://www.cmsnl.com/ . Great folks to deal with, FAST shipping!
As expected both cam chains were roached, and the primary in the bargain as well.
Pistons got new rings (thanks again Mitsuo @
https://www.cruzinimage.net/ ).
New clutch friction plates installed, metal plates looked minty. Valves & seats were lapped to freshen them up.
MAJOR shout out to my good friend Ron Marshall! He stepped up and offered me a deal I couldn’t refuse. From the bowels of an ‘82 lump with 25,000km. he supplied replacement primary, counter & main transmission shafts as well as both cam chain & primary chain guides, primary chain tensioner, and alternator clutch plates (one of which was BRAND NEW from his private stash). I had the parts I needed within days of my asking him. SUPER guy.
As always my ‘support’ dog, Oliver, just had to be in the thick of the action