QuestionI have a superhawk that i am restoring and i stripped the bike down all the way except getting the last chrome piece off the forks but that is my secondary concern .the piston,i think the left side cylinder is seized because the intake shows corrosion, and i thought that i would be able to disassemble the engine and get it rebored but i dont know how to get the piston unseized short of putting it back on the frame after putting it back together ,and putting it in gear and rocking it back and forth. what should i do? i also have a 1971 cl350 that 1 cyl. runs funny and a friend told me the rubber diaphragm was probably pinholed although i didnt see any on inspection . it was almost like your recent reply to someone about the cb350 . i appreciate your taking the time to answer peoples questions . i also like the site honda305.com . i think it is the site with the electronic ign. upgrade i will get for my 'hawk. well thanks again.
AnswerLen, Honda made a special U-shaped tool with adjustable special bolt ends that will engage the small holes on the fork seal holder to loosen it up for you. Try a soft strap wrench, like the ones used for oil filters. Some of the seal holders are on real tight, though.
My engine repair guides, both in print form and on CDROM, have a step by step disassembly procedures about how to get the seized pistons out of the cylinders. Basically, I adapted an inexpensive steering wheel puller to PUSH the pistons out of the cylinders. I had an old Harbor Freight tool, which slipped over 3 of the four studs. I stacked deep sockets over the studs so I could get the whole setup firmed up, holding the stack in place with some nuts on the cyl studs. I used a very LARGE socket on the 4th stud, that was wide enough to catch the edge of the puller plate, then stacked sockets on that stud to hold it steady. The book has a photo of the installation.
Some pentrating oil is helpful, here, but using the blunt end of the puller bolt push tool, you can screw the center bolt down on the piston a little at a time, until it breaks the corrosion bond loose. Go slowly, as the opposite piston will be coming back up and start cocking the whole cylinder, in some cases. This usually happens more with an engine that is seized on both sides, though. That should do the trick for you.
DO NOT pound down on the top of the piston, as the needle bearings can be damaged on the big end of the rod. Trying to turn it over with the rotor bolt will usually cause the bolt to shear off inside the crankshaft end... not a good thing.
CB/CL350s do suffer from damaged diaphragms on the carb tops, which causes them to run awful. If that is not the case, then you have to check the engine over for equal compression, proper valve adjustement, clean and lube the spark advancer, clean the point faces thoroughly, gap them to .012-.016", set them to open at the F and LF mark and then watch the points when the engine is running. If the points are arcing severely, then the condenser for that side is either bad or the connector is loose or disconnected. WHEW... I have to go take a nap now! :>)
Bill Silver www.vintagehonda.com
