2017 began with just my 65 Mustang, 2002 Tacoma, 2001 W650 Kawasaki and a PCX150 Honda scooter in the fleet. In the past two months, the fleet multiplied greatly to include: 1963 CA77, 1962 CB77 Type 2 café racer, 1965 CB160 in CR93 replica form, 1980 GN400 Suzuki with 3400 miles, a 1981 Yamaha XS650 with 2890 miles and recently a SYM150 Wolf project bike. I did sell the Mustang, though…
All the non-Hondas brought new lessons to me in the way of trouble-shooting, tuning and working with Mikuni carburetors. You have to remember that basically all engines/bikes have to operate on the same principles, but the execution of those designs can vary widely.
The GN400 was obviously off the road for at least 10 years, judging from the gunk inside the carburetor. After what I thought was a good refresh of the carb’s innards, the bike was quite hard to start (kickstart only) and once running it wouldn’t rev over 5500 rpms. Thinking that the carb was “clean enough” I turned my attention to the ignition system, which according to GN400 forums, had issues with the CDI modules. The CDI system has an electronic advance curve and apparently sometimes the spark advance portion fails so you get a bike that starts but won’t pull good power in the upper revs. That is what it “seemed like” was happening, so I rounded up a used CDI from a local salvage yard and tried it out. Same result! Either I had two bad CDI units or the problem was still in the carburetor.
My friend, Scott, who just went through carb issues with his Yamaha SRX250, kept saying to check the emulsion tube, but initially I couldn’t figure out how to get it out of the carb body. Finally, a look at the parts books and studying the carb itself revealed that the emulsion tubes come out through the carburetor throat and not out the bottom like Keihin carburetors do! Aha! Gunk and corrosion were plainly present which would certainly point to performance issues with high rpm running. I put the carb back on and it ran WORSE! Reconsidering my reassembly of the carb slide diaphragm, I rechecked the carb and found the diaphragm was not seated fully in the top groove, causing a big air leak that prevented the slide from lifting all the way. With the carb remounted for the 4th time, success was achieved! The bike ran up to redline without hesitation.
The 1981 XS650 Yamaha also showed up with gunky carburetors, but now I knew how to handle the emulsion tubes and the cleaning went well, except the tip of the float valve needle broke off from old age and old gasoline deposits. I installed another needle that looked the same, but that carburetor continued to overflow when installed on the bike. There was also a fuel leak coming from the fuel T fitting that connects the two carbs together. When the carbs were split apart to remove the fitting, the expected o-rings were not there at all because the fitting was not designed to fit o-rings! The plastic coating on the metal T was apparently supposed to seal up the space in the carburetor fuel inlet passage, but it wasn’t doing it anymore. Checking on-line, there were some aftermarket carb T fittings with o-rings to replace the lame OEM version.
I decided to attempt a repair on the fitting, so ground off the ends, ever so slightly and fitted Viton o-rings into the carb body recesses. When the carbs were bolted back together, the fitting butted up against the o-rings and the fuel leak was solved, at least for now. The bike fired up on a fresh battery and sounds just like what it is… a super low-miles vintage Yamaha XS650, ready to ride once again.
Acts of kindness…
In the past month, I have needed a positive battery cable for a CB77 and a muffler bracket for a CB350F, but of which were not to be found in internet searches. Putting out a plea to the F-160 Yahoo group yielded a good used cable, which was sent for free to me from a fellow Honda connection. It turned out that the CB77 cable was superseded to the one for a CB160, which is what prompted me to turn to that F-160 forum for help.
The CB350F 4:4 muffler installation was stalled for lack of brackets. A new right side bracket turned up on eBay from a friend in FL for just $35. Again, I pleaded for help to find a decent left side bracket and once again one was offered to me for free from a Honda fan who I had helped with questions over the past year. It arrived sandblasted and primered, looking like a new part that just needed a quick coat of black paint to finish off. These kinds of generosity speak volumes for fellow Honda enthusiasts who share information and parts with each other in times of need.
The final big act of kindness came from a couple of gentlemen who offered to sell me back the 1962 CB77 café bike, which I had built in 1991 from a rolling skeleton of a domestic model CB77 chassis. They had picked up three CB77s from a neighbor whose husband had passed away a few months before. I learned about a stack of abandoned, neglected CB77s from a man who had bought a SAAB Sonnet from me a year before and had just purchased a 1967 Mustang from the widow. He saw the bikes, which had been standing outside near the ocean for some 20 years and took a photo, which he passed along to my friend Scott. Scott passed it to me and I went to look at the remains. When I arrived, one neighbor who had bought the three “good bikes” in partnership with his neighbor across the alley, popped in to see who was looking at the old bike collection. He introduced himself and asked if “I knew anyone who works on these old bikes.”
He showed me the beautiful black 1965 CB77 which he had claimed from the purchase and mentioned that there was another stock black bike like his, plus a “1962 Red café bike” that they were interested in selling! I got chills when I heard that mentioned, as I recalled selling such a bike to a collector in this area back in the early 1990s. The widow kept looking at me, while we were conversing and said “I remember you. My husband bought that bike from you back in the 1990s!” It WAS my old powdercoated Scarlet Red 1962 CB77 café project, hidden away for 25 years.
After consulting with his partner in the bike deal, they offered to sell me the bike for the same price they bought it for, which was more than reasonable. As part of their kind offer, I returned the favor by bringing home the black bike for revival which took about 6 hours and a few hundred dollars worth of parts. After a good tank cleaning, new battery and carb overhaul, the red café bike came alive once again and I was treated to the memories of building and riding it back in the last century!