Don't have an account yet? You can create one. As a registered user you have some advantages like theme manager, comments configuration and post comments with your name.
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Fri Sep 09, 2011 7:28 pm Post subject: Someone please kill me
Hey all So I've come to the conclusion (and this is something many of you have wisely pointed out) that owning an old bike is not for the faint of heart. Sigh.
I have a 68 CB350. Since my top end rebuild (my first) that I did in the spring of this year, the left cylinder stumbles at idle. Since the rebuild, there has also been a fluid, that I had THOUGHT was gas coming from the left tailpipe. I switched the carbs last week and lo and behold, the RIGHT side started stumbling. "THERE'S THE CULPRIT" I thought. So I took the left carb apart, cleaned the heck out of it, and also found that someone had put non-stock sized jets in. I found stock jets (primary and secondary main, also pilot) and replaced them. I also replaced the float valve and needle, the float, the little rubber plug on top of the pilot jet and the needle jet, just to be safe. I also re-set the float height and the air mixture screw. I put it back on the bike, fired it up. Same problem. So maybe the carb WASN'T the problem (or only part of the problem as it is SLIGHTLY better). Then it struck me, maybe the liquid coming out my tailpipe isn't gas at all. I mean, it doesn't really smell like gas. I assumed this was because it had gone through the engine, but maybe that's wrong. It's all black and shiny, maybe it's oil. If it is in fact oil, does anyone have any ideas what it could be? Did I totally screw up the top end job? I'm considering dousing this bike with gasoline at this point and watching her burn.
Joined: Dec 26, 2007 Posts: 1281 Location: Scottsdale, Arizona
Posted: Fri Sep 09, 2011 8:21 pm Post subject:
Dave,
I don't intend to kill you, but I will offer some advice based on what you've been posting. Sell this bike. Now. Go get yourself a relatively new bike, have it serviced by a professional, then ride it. Enjoy it. But don't get within 100 yards of it with a tool in your hand.
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Fri Sep 09, 2011 10:57 pm Post subject:
Ha ha A do appreciate the advice Stu, but I'm just frustrated for now, lol. Besides, how am I supposed to eventually KNOW about these bikes (like you guys) unless I first DON'T know now, swear up a storm, and then learn. Also, I'm stubborn as hell, so this bike will be with me until one of us kicks it Any thoughts on the oil?
Joined: Nov 02, 2008 Posts: 1085 Location: New Zealand
Posted: Fri Sep 09, 2011 11:46 pm Post subject:
Dave, I don't know if you have a riding history prior to this bike, but I can tell you Stu's advice is actually really sound if I consider it in the light of my own experience. Nearly 40 years ago when I knew almost nil about motorcycles I bought an Old Vespa that was running well, rode it a little and did lots of work on it that wasn't needed and actually broke critical, un-obtainium bits, and basically stuffed a machine that was sound when I started out. A couple of years on I again took the plunge,having learned from my disaster, buying on tick a year old T350 Suzuki twin and rode it and rode it and rode it. Slowly over the years I progressed beyond basic oil change type servicing onto bigger jobs. For me it was easier as an untrained self taught tinkerer to slowly build skills and confidence by working on bikes I'd already become very familiar with through riding first. Somehow its easier to get the tinkering, and the bigger jobs, 'right' when you have a well developed understanding of that particular machine first.
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Sat Sep 10, 2011 4:02 am Post subject:
Russell, thanks. I know you're trying to help. I know Stu is trying to help as well (mostly due to all his help in the past, lol, as his last comment was a bit dismissive and I think more of a reaction to the title of my post). That said, I'm actually learning a lot. I'll skip the long explanation, but to sum up: I am never ever going to sell this bike. I'm never ever going to stop trying to figure it out and learn about it. (The good news is that there really are no unobtainium bits on the cb350s it seems). So, all that said, anyone have thoughts regarding the oil out the exhaust? If not, no biggie
Joined: Dec 26, 2007 Posts: 1281 Location: Scottsdale, Arizona
Posted: Sat Sep 10, 2011 7:47 am Post subject:
davem222 wrote:
Ha ha A do appreciate the advice Stu, but I'm just frustrated for now, lol. Besides, how am I supposed to eventually KNOW about these bikes (like you guys) unless I first DON'T know now, swear up a storm, and then learn. Also, I'm stubborn as hell, so this bike will be with me until one of us kicks it Any thoughts on the oil?
Dave,
Swearing, stubbornness, and repetition won't provide you with actual knowledge or skill. You should take a course either online or at a community college before attempting anything like major engine rebuilding. And it would be great if you could find someone local to mentor and teach you as you do this major work.
The oil? Just an educated guess, Dave. You may have broken a ring putting the cylinder on. It's also possible, if you used the new style 3-piece oil control rings, that you installed the expander with the ends embedded over each other instead of butting against each other. Did you install the compression rings with the letter stamped on the rings facing up? Maybe the head gasket developed a problem that lets oil from the cam chain tunnel get sucked into the cylinder. Re-torque the cylinder nuts and see if that helps. As I said, it's just a guess. But if you actually have that much oil coming out the muffler, the engine isn't going to run worth a darn regardless of what you do with the carbs.
Oh, by the way - on one of my first bikes, I was "de-coking" as per the owners manual. Didn't own a torque wrench. I stripped one of the cylinder studs out of the crankcase. Tapped the crankcase to an SAE oversize and installed a piece of all-thread from the hardware store. Then I rode the bike to a town about 50 miles away and traded it in for a new bike. I'm sure the next owner would have liked to strangle me, if he could find me! After that, I bought some trade school text books and started reading.
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Sat Sep 10, 2011 10:04 am Post subject:
Stu,
Again, I know you are trying to help, so I want to say thanks, but I'm curious as to what specifically in my posts leads you to believe that I've neither taken a course, nor read books (such as the trades school textbooks you read early on) and that I am relying on only swearing, stubbonness and repetition to provide me with skill?
Joined: Dec 26, 2007 Posts: 1281 Location: Scottsdale, Arizona
Posted: Sat Sep 10, 2011 10:46 am Post subject:
davem222 wrote:
Stu,
...but I'm curious as to what specifically in my posts leads you to believe that I've neither taken a course, nor read books (such as the trades school textbooks you read early on) and that I am relying on only swearing, stubbonness and repetition to provide me with skill?
Dave
Perhaps this? "how am I supposed to eventually KNOW about these bikes (like you guys) unless I first DON'T know now, swear up a storm, and then learn. Also, I'm stubborn as hell, so this bike will be with me until one of us kicks it"
Sorry I said anything, Dave. Carry on, and good luck.
Joined: Nov 02, 2008 Posts: 1085 Location: New Zealand
Posted: Sat Sep 10, 2011 2:50 pm Post subject:
That mystery fluid from the tail-pipe isn't water blackened by an overly fuel rich exhaust is it? What sort of quantity are we talking about?Have you had the bike running smoothly enough for it to be ridden at road speed long enough to warm the pipes right up and clear all the crap out?
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Mon Sep 12, 2011 7:24 pm Post subject:
@ Russell, I've had it running for several months now, and at road speed. It may in fact be sooty water, I really can't tell. It SEEMS in it's feel to me like oil, but I don't know what way to test it. I suppose I could drip it in a glass of water and see what it does.
@ 450p It doesn't smoke at all, which is something that puzzles me. I figured if it's oil it should smoke. It runs fine (or as well as I can tell) past Idle, no problems at all. I regularly have it up at 60 or 70mph, no stumbling, 5th gear, 7k rpm, etc, and all the way through there it's fine, but at idle it seems to stumble and there's that drip, lol. It's a puzzle indeed.
@ Stu: As you have helped me immensely in the past without asking anything in return, please know that I respect your judgement regarding bikes and your generosity of spirit immensely. So it heartens me and inspires me that you have the good sense to feel sorry for making your comment that I should just give up on older bikes. I will refrain from pointing out the glaring error in your logic of my quote justifying your original advice unless you specifically wish to learn of it and from it. You and so many members of this forum have helped me more than you can know. Also, I know that written text can often be misinterpreted because it lacks the tone and inflection of speech, but please know that I am being 100% sincere in writing this
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Mon Sep 12, 2011 8:17 pm Post subject:
Also, just a bit more info, I checked the oil level last night: still full up. I have had this prob for a few months and I haven't changed the oil in that time.
Joined: Nov 02, 2008 Posts: 1085 Location: New Zealand
Posted: Mon Sep 12, 2011 8:27 pm Post subject:
I wait with interest to hear the answer(s) when you get the mystery solved.Right now it sounds to me like the issues are not inside the engine.Seems like the issues are around the parts of the carbs that are involved when the throttle is closed.Unburnt fuel and condensate is my pick for the mystery fluid.I wouldn't totally rule out ignition issues at idle either if the bike is still on points.
Joined: Jul 31, 2008 Posts: 147 Location: Los Angeles
Posted: Mon Sep 12, 2011 11:09 pm Post subject:
It is still on points. I'll go through and do the timing again (I had done it, I thought well, with a timing light, but it couldn't hurt to double check, or triple check, lol). I may stop by my local mechanic for some guidance, but I will definitely keep you posted as to the mystery fluid Thanks for the help!
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You can attach files in this forum You can download files in this forum
So I've come to the conclusion (and this is something many of you have wisely pointed out) that owning an old bike is not for the faint of heart. Sigh.
