I rode the CB650 maybe another 1,500 miles after the last post. The smell of gasoline got stronger each time; I found I had to put the bike away with the petcock closed or the garage filled up with fumes.
I finally quit riding it when I realized raw gas was leaking out of the carbs. I also discovered an oil leak, coming out around the shift shaft and dripping onto the left exhaust pipe. It was evidently leaking only while the bike was running, so there was no puddle in the garage to reveal the leak.
There was no avoiding it… my bike needed professional help.
I asked a fellow rider who owns a vintage Japanese bike who he would trust to do the work, and he recommended Cycle Tech at Fremont, Iowa. When I say “at” Fremont, I mean out in the middle of nowhere north of Fremont (which is itself somewhat like the middle of nowhere).
So I called up the man in charge and discussed my bike’s issues, and he shot me an estimate. It was more than I hoped, but less than I feared, and I took him up on it.
They pulled the carbs, fitted new gaskets and seals, put ’em back together and synced them up. They also replaced the bad seal on the shift shaft… problem solved.
Things made of rubber, you know?
I didn’t think to ask them to change the oil, but I picked up oil and a new oil filter when I went back to get the bike.
So anyway, moving on… last weekend I set out to change the oil in the CB650. Draining it was easy, but the oil filter bolt head was pretty chewed up. I couldn’t get a wrench to grab it, nor would my hex-head vice grips do it.
Finally I put curve-jaw vice grips on it, clamped down as tight as I could get them, and tapped on the vice grips with a rubber mallet. After a few judicious whacks, the bolt broke loose, and I was able to complete the job.
I considered getting a replacement OEM bolt (Honda part number 15420-333-000), but the few places that had them listed the price at around $55.00. There had to be a better solution… and there is. I discovered that Emgo makes a replacement oil filter bolt for the CB650, and it has a 17mm head instead of the 12mm head on the stock unit. Should be harder to round it off. The Emgo part number is 11-46400; Amazon.com has it here for $14.97 with free shipping, which is much better than the OEM part price. K&L Supply also makes a replacement for this bolt, their part number 19-1387, available on Amazon.com here for $15.93 + $8.74 shipping; still a better deal than the OEM part. Of course, these prices are just good for right now, and will surely change in the future.
Just for the record, I checked some other vendors for this part. Dennis Kirk has it here, for $16.95 plus shipping. Rocky Mountain ATV/MC does not seem to have it, which I suppose isn’t that odd given their obvious off-road focus, except that they do have many other parts for the CB650 including the K&N oil filter, and they carry other Emgo parts. Didn’t find the K&L bolt on either site.
For the moment I’m going to use the existing bolt, but when the bike is due for another oil change I’ll get a replacement.
While changing the oil, I thought about other periodic maintenance items, and decided I should service the air cleaner as well. I pulled it out and discovered it was soaked with old gasoline. I knew the bike had backfired from time to time, especially when cold or running on choke, so I assumed it had been blowing gas back into the airbox. (I’m hoping that sealing the carbs has fixed the backfire issue.)
Well, then. Time for a new air cleaner. I ordered an Emgo replacement, part number 12-90700, on Amazon.com here. The current price is $10.69 with free shipping. The Honda OEM number is 17211-460-000. Note that the only shop manual I’ve found online is for the 1979 model year; they completely changed the airbox and filter in 1980. If you have the 1979, this information won’t apply to you.
The replacement filter came in, so I set about installing it. There’s a rubber seal that fits around the flange on the filter; you have to take it off the old filter and put it on the new one. While I stood there putting the seal on the new filter I noticed a shine from inside the airbox. A wet shine, to be exact. I figured it must be some more gasoline. I grabbed a big handful of paper towel and stuffed it into the airbox, then pulled it back out soaked with sour gas. Did this twice more before I was sure I had it all… I was surprised how much was in there.
I went ahead and installed the new air cleaner and buttoned up the bike. I now had a pile of gas-soaked paper towels… kind of a fire hazard, obviously. I stuffed the paper towels into the box the new air cleaner came it, took the whole mess out to the driveway and set it on fire. After a moment’s thought, I put the old gas-soaked air cleaner on top.
It all burned down to ash in about half an hour. I fished the metal bits from the air cleaner out and threw them in the trash (after ensuring they were no longer hot enough to be dangerous), then stamped around on the ashes to disperse them. All cleaned up.
I’m almost afraid to say it, but I think the bike is done. I’ll try to remember to post some pictures soon!