Deconstruction of the Sea Beast complete.
Since the proclamation of my intentions to become an AHRMA racer, time seems to have slipped into overdrive. My to-do list gets longer, but more specific, all the time, and I frequently find myself taking meals (read: snacks) in the garage. Nitrile gloves serve to protect my food from my greasy hands.
In the inaugural post of this series, I Am a Racer, This is My Machine, I outlined the series of events that lead to my being in possession of three CB350s, and my subsequent decision to race the amalgamation of those motorcycles. However, as noted in that post, two years had passed between the acquisition of the first bike and my invitation to the world to come into my garage (via the internet, of course) and see how a vintage race bike is built. While that process is most assuredly moving towards a raucous conclusion, I thought it would be prudent, if not interesting, to take a step back in time and examine the two years following the initial purchase, during which I polished my skills with a drill and easy-out set, and made up myriad new swears. At this point you might be protesting “But, Mr. Peabody …” but I can’t hear you, so into The Wayback Machine we go.
Just a little bit of rust.
Despite being uninitiated and possessed of only intermediate mechanical aptitude, I understood that complete disassembly of one or more of my project motorcycles was in order. The thought process was that I would remove every removable part of the original bike, and then replace what was lost, ruined or never present with bits from the two donor bikes. So far this model has served me relatively well despite the lack of appreciation I once had for cataloging. At this point I would like to interject a piece of advice for anyone considering undertaking a project like this for the first time: catalog everything. Take photos, take notes, take your time. If a screw or bolt is broken or has to be drilled, photograph it, measure it, note its home. I did not perform this step efficiently and it has bitten me 95 percent of the times it has resurfaced. Hear me now, or hear me again later as the echoing voice of I Told You So in your head.
The frame, partway through removing the paint.
The destruction of a motorcycle can loosely be broken into two categories; engine and chassis. I started by separating the engine from the chassis and assessing its worth. Finding essentially none, I began heavy-handedly disassembling the seized hunk of metal from the top down. Inside the cam box was a serviceable camshaft, four rocker arms and four rocker arm pins. I cut the old cam chain to get it out of the way and allow proper removal of the camshaft. Under the cam box lies the cylinder head. All three bikes ended up having some kind of issue that would make their heads difficult or expensive to use. I sourced what my machinist would later describe as a good core online for $25 + shipping. I was able to collectively harvest four serviceable valves from my donor engines, the R/D Valve Springs beehive spring set rounding out a complete head. The cylinders proved formidable opponents. As I’ve said, the pistons were seized in the bore in an unknown fashion for an indeterminate period of time. I tried prying, I tried hammering, I tried soaking, I tried pleading, I tried a bigger hammer, I tried drilling holes in the top of the pistons and I tried fire. Finding none of these effective, I acted out of desperation … and it worked! I procured a hole saw of the highest quality readily available in a size slightly smaller than the bore, and I procured a jug of cutting oil. Using extreme caution as to not wreck the cylinder walls, I began boring into the rusted pistons. Eventually they were released from their bonds and I was yielded a pair of cylinders for my efforts that my machinist was able to clean up and bore over. Finally, I split the crankcase halves and inspected and cleaned its contents. This was a really fun process for me; I now have a deeper understanding of how the engine and transmission function.
The CB frame, brought to the office for inspection.
Before beginning reassembly, I hauled all the engine components to the Motorcycle Classics garage and put them through our Skat Cat 40 blast cabinet. I blasted the exterior surfaces of everything with the Skat Magic Abrasive crushed glass media; it gave all the aluminum a matte finish that I find very attractive. Different media will produce different finish results. A would-be blaster of engine components should also choose their media wisely as crushed glass remnants are just about the absolute last thing you want your engine to be full of! They can block oil passages, score machined steel surfaces and wreak indescribable havoc if not completely removed during the post-blast cleaning process. Once I was certain that any vestiges of crushed glass had been removed, I began reassembling the engine with fresh gaskets, seals and copious quantities of assembly lube.
Fire, because why not try it?
The chassis didn’t leave much to be salvaged; you have presumably seen the wheels, and soon you will see the forks that have been rejuvenated by Race Tech. Since AHRMA regulations for the Production Lightweight class I will be racing mandate the use of a stock seat pan, I will try to breathe new life into one of my seats. With a little elbow grease, I believe I can also salvage one of my fuel tanks. All lights and non-essential chassis pieces were eliminated, and the difference is being replaced with new parts. The frame was stripped of all its paint so the bare metal could be evaluated and certified free of cracks. The down tubes of these bikes tend to hold water in the bend at the front of the engine cradle, and as such, my frame had rusted through. A local welder was able to inexpensively repair the hole and paint prep began. Since at this point in time this was still a hobby project, I decided to have fun with the design aspect. I visited a local automotive paint supply store, where I pored over swatches until I determined the color of my frame was to be “Milk Tea Pearl.” I simultaneously grossly underestimated how much paint would be required, while also grossly underestimating the cost of packaging high-end automotive grade paint into rattle cans. Two to three visits to that paint store, and roughly $150 later, I have a paint job I’m pretty proud of. If I had this to do again, I would either rattle can it black with $10 of Rust-Oleum or pay for professional powder coating. I’m here making these mistakes so you don’t have to.
The cut piston.
There it is, two years of my efforts reduced to a few minutes of reading. I’m very excited about the state of the bike and I can’t wait to share it with you in a few weeks! Keep your eyes peeled for the next blog, and maybe a bonus video of the first start of the engine. If you haven’t already, mark your calendar for the Topeka, Kansas, AHRMA race, June 28-30, at Heartland Motorsports Park. See you there!
The engine case, empty and clean.
The transmission, going back together.
"Sea Beast" Parts Suppliers