Description
13 Page – PDF Download – Complete Series – Honda 750-4
“There’s no smoke without fire and this Honda was smoking badly. It was also rattling. Bike surgeon Chris Dell operates in this first part and makes his diagnosis in the next issue.
This engine had to be stripped because of two problems. One was the amount of oil it was burning (not to mention the smoky exhaust!), the other was a loud rattle all the way from tickover to 500rpm.
My preliminary diagnosis was a loose alternator drive chain causing the rattle, but the oil consumption problem was much harder to diagnose. Possible causes include leaking valve stem seals, tired piston rings, piston damage, or damage to one or more bores.
The rattle had been present for thousands of miles but the engine had continued to run well, albeit with a steadily increasing appetite for oil and an ever-present large cloud of bluish smoke.
The first step (often overlooked but always important) was to clean the engine and remove it from the frame. Removal was easy enough with useful help from an assistant and the then engine was cleaned again, even more thoroughly.
Before that, though, the inlet ports were blanked off to prevent water or degreasant getting in.
Once the engine was truly clean, the strip could begin. The oil filter area kept on dribbling oil, so was blocked off with a screw of paper. This engine plate was left in place on the crankcases because the bolt was seized to its nut. Fortunately, this would not get in the way during the stripdown.
Eight Allen screws retained the camcover. Once these had been removed the cover lifted off readily, revealing the camshafts and camchain guide.
After its bolts had been removed this oil pipe was then removed followed by the other one and the camchain guide…”
13 Page – PDF Download – Complete Series – Honda 750-4
