Having been a motorcyclist in some form or other for over 50 years, I have owned several hundred cars and motorcycles, but seldom have I had any given to me for free… until now.
In the past month I received a “free” Honda S90 (Super 90) which had been partially used as a dirt bike and was wearing a very unattractive yellow paint scheme. The engine was frozen and we had to cut the drive chain off so we could even roll it into my truck. The last tags on the old CA black plates indicated a 1970 registration date. The bike was given to the man I received it from after the owner was moving out and had to get rid of the poor little Honda 90, which had been sitting in the back yard for many, many years.
The bike was rolled off the back of my Tacoma and onto my new Harbor Freight bike rack for disassembly and evaluation. The bike still wore its speedometer and headlight, plus the stock air filter and carburetor setup. Only the exhaust pipe had been changed to an upswept design with the correct exhaust port angle. Honda made major design changes in the early years, including re-angling the exhaust port exit. Many of the “early” Honda S90 parts will not interchange with the “late” versions. See this site for some of the details: http://s90partspuzzler.blogspot.com/
Ordering gasket kits proved somewhat futile, as the complete kits are all for “late” engines. I eventually had to buy a half-dozen separate gaskets that were “early” model specific in order to rebuild the engine. And that engine build was not an easy task, as it took over an hour of serious work in order to get the piston, which was half way down the bore to come out the bottom of the cylinder.
Ultimately, the end of the rod wound up being bent and the cast iron sleeve pressed into the alloy barrel had a small fracture line in it from all the violence that occurred during the piston removal.
Fortunately, our local machinist wizard, Bruce Barker, came to my rescue in straightening out the bent rod and later straightening out a pair of fork tubes. Having a guy like that in the motorcycle community is indispensible for these kinds of repairs.
As the S90 came apart, I discovered a damaged swing arm as well as a broken off upper shock mount stud, so after disassembly, the S90 frame was set aside, along with a pair of rusty wheels and a box of other misc parts that were beyond salvaging. In the middle of this adventure, I recalled that a friend who specializes in quality auto body work had a CL90 bike that was pretty complete, but the engine was not repairable for a reasonable cost, so it sat unused for several years. I called about the bike and we struck a bargain where I paid for the bike and also a quick paint job on the original S90 gas tank.
Slowly, the bike is turning into a hybrid collection of S90 and CL90 parts, melded together to make something out of nothing. Renewing these small bikes is less costly than most, but when you buy a new piston kit, gasket kit, seal kit, fork seals/boots, handlebars, control cables, battery, petcock and carburetor parts, drive chain, sprocket/hub cushions, tires/tubes/bands, misc rubber parts, headlight and all the other dozens of parts that must be renewed, suddenly the “free motorcycle” has you in debt for $1,000 or more, not including many hours of time and parts chasing. Of course the bike had no title or paperwork, nor did it have a key. Leaving the ignition switch with a local locksmith shop to remove a broken key and supply two new ones left me facing a $50 repair bill. New aftermarket switches are less than $20, so trying to save the old switch wasn’t proving to be a wise move.
The front wheel on the CL90 chassis was covered with fork oil due to blown seals, which kept the front rim looking new, once the old oil was removed. The tire was an original and pumping up the old tube actually kept the tire fully inflated while the bike was on the repair rack. A cheap a/m tire from an eBay seller proved to be problematical as it had a 2003 date code, was somewhat warped from years of storage on the side and was partially full of dirt and debris, which needed cleaning before it could be mounted on the rim. The stock 2.50x18 tires are somewhat tricky to mount on rims, especially getting the valve stem inserted properly.
The engine’s cylinder head had a lot of water that had come up the exhaust port through the aftermarket exhaust pipe, so both valves needed replacing and the seats required re-cutting. In the past year, two different friends gave me misc sets of OEM Honda factory valve seat cutters to fit everything from 50cc to 450cc engines, so getting proper valve seats profiled correctly was easily done here in the shop.
The transmission required some mixing/matching of parts and pieces to get a good set of parts for the manual transmission function. Honda changed the root sizes of the shaft splines, so you can’t just swap on a late gear on an early shaft. Eventually, the transmission had one early shaft of gears and one late shaft of years, all being selected by an early style shift drum and forks.
The whole engine as a big ball of corroded aluminum, requiring full disassembly, then soaking in Simple Green to degrease. Then a nearly 100% straight phosphoric acid bath was used to neutralize the scale and aluminum corrosion. Several hours of gasket scraping and wire brush work was needed to get the parts close to original condition. All this work for a “free motorcycle”!
Oddly enough, the carburetor bowl was clean as a whistle inside, but the float was dented in so a replacement was ordered. The petcock was rebuilt with new rubber bits and all new seals and gaskets were used wherever needed.
The speedometer showed some 11,000 miles so there was little surprise to discover that the brake shoes were severely worn down. Honda used the same shoes for the little Cub 50s and the 90cc series machines, so the parts are readily available. Once the fork tubes were straightened out, new seals, fork boots and oil were used to freshen up the front end. Some cool aftermarket low handlebars were sourced from an eBay seller, which will go along with the “café” theme of the bike. An interesting metal front fender was on the bike when received and both fenders were painted a deep metallic burgundy color.
Hot on the heels of the S/CL90 project, a friend gave me a 1983 XL200R Enduro with a title (nice for a change), showing just 4400 miles on the dusty speedometer. It was another “backyard” bike that was rode hard and put away wet many years ago. The gas tank has a HUGE big dent in the side, the whole thing was dirty, dusty and all scratched/dented up from top to bottom. The rear tire was oversized and bald in the middle while the front tire looked almost unused. The engine, of course, was seized up solid, so a whole bike teardown was in order. The rear fender was sporting an old Suzuki tail light, mounted up on a bent-over rear fender. The fender assembly actually has a thin metal reinforcement below the plastic outer fender. The fender was disassembled and a decent used plastic fender section purchased on eBay. The inner fender support was taken to my friend Rob North for some welding up of the many small cracks and reinforced in the middle with a big flat washer.
During the engine removal process, I managed to drop the entire engine on the big toe of my left foot, which was wearing Crocs at the time. It would have been so much easier and safer to just have put a jack beneath the engine cases, but somehow I thought I could just wrangle it out of the frame with one hand.
With the engine sitting on the ground, I was able to disassemble the top end for inspection. Despite a full air filter assembly in place, somehow water had worked its way down the intake port and into the cylinder, sticking the piston in place, mostly in the down-stroke position. There was a lot of rust, carbon and other debris on top of the piston which was vacuumed off at first. A good spray of the WD-40 penetrating oil product helped to lube things up I guess, but to my surprise a couple of medium whacks with a brass drift knocked the piston loose and the cylinder slid right off the engine with little effort! That doesn’t happen very often!
A .75mm oversized piston kit was procured from an eBay seller as well as a top end gasket kit which was ordered for this model, but a KX80 kit showed up instead. The seller finally replied to my pleas for the correct kit and it was dispatched forthwith. The cylinder was taken to my reliable machine shop buddy, who called back the next day saying that there was still some staining on the cylinder liner and “Oh, by the way, I dropped the cylinder on the floor and broke off a fin.” I might have been more upset if this was a Concours machine, but as an old beater dirt bike I wasn’t too concerned.
A proper-sized rear tire was purchased through the local dealer and installed while I waited. A new chain and battery await the reinstallation of the engine. The carburetor cleaned up okay and a new aftermarket petcock purchased to bypass the non-repairable OEM unit.
Current status 9/21/16: After wrestling with the engine installation for way too long, I finally realized that I had mis-installed the two engine mount bolt spacers, which are about a ½” difference in length. Once that little “correction” was made, the engine bolts all started to magically line up as they did when the bike was built at the factory! Duh! Anyway, the bike is about 80% reassembled now with prayers for an actual start-up event in the next few days.
The S/CL90 project is awaiting some throttle pieces and point plate cleaning and installation.
Meanwhile, my pride and joy 1965 Mustang 2+2 fastback, which has been pretty reliable all summer, suddenly belched up about a quart of ATF on the driveway. Crawling underneath revealed little in the way of a source and it wasn’t actively leaking when inspected. A call to the transmission shop that had done a service on it a few months ago mentioned that when the cars are not run regularly (and parked nose uphill) the torque converters will drain back into the transmission case, overflowing out the vent fitting! Barring any leaks at the speedo cable drive fitting o-ring, that is the probable cause of the leak. The shop has been busy, but thought they might be able to squeeze it onto a lift for Thursday morning.
Bill “MrHonda” Silver
I genuinely lol'ed at the additional frustration of dropping the motor on a toe with minimal Croc protection. There's always some additional struggle that happens during a complex rebuild, usually involving badly scraped knuckles or stabbing oneself with a screwdriver.ReplyDelete
So far my CA77 has treated me well as it comes out of its decades long hibernation. My '82 Kawasaki AR80 however has defied being the cheap n easy restoration I'd hoped for having now blown up on the dyno 3 times while trying to tune it. It's reassuring to see people more talented than me struggle too. 😀