79 CB 200t: Starting to think I bought myself a lemon.

sixsixtie

New Member
Some back story. I've posted some of this before but I'll do it again.

back story:

Bought it about 4 months ago.

When I bought it it idled extremely high. Like over 5,000. Guy was clueless and it was stalling so he just adjusted it until it would maintain an idle, which as I said, was stupid high. I asked him why he didn't try and actually attempt to find the reason's for the poor idle rather than hodge podge a "fix" and treat the symptoms he said he didn't have the money or knowledge to work on it. Ok, fine. He said he would never drive it anywhere because it would foul the plugs and leave him stranded (Quel suprpise).

I bought it anyway. I figured a solid carb cleaning and all around tune up would fix the problems. (I know probably silly. If the guy was that clueless what else did he fuck up.) I pulled the trigger anyway because in Vancouver old CBs don't come around often and I had been grinding craigslist for a year straight with no luck. I didn't want to wait even longer. I had some mechanical knowledge but not much. I am a quick learner and with the internet as a source of information I figured I'd learn on the go and get this bad boy up and running.

Work done:

  • First thing I did was get those carbs off and gave them a serious, serious, clean.
  • Rebuilt them with a keyster kit. (made sure all jets were the proper size)
  • Put them back on a synced them and tuned them to manual specs.
  • This fixed the high idle. but it would now idle only if I kept on the throttle
  • adjusted cam chain using the tensioner bolt
  • I adjusted the points. this allowed it to idle but would foul the plugs after a 5-10 minutes of idling
  • Replaced the plugs
  • pulled the tank and cleaned it.
  • Replaced all the internals of the petcock (it was in awful shape)
  • replaced the fuel lines
  • dude claims the wires are new(ish i think he said last summer)
  • noticed that it was running strong on the left side but the right side was weak and the right muffler would take much longer to get hot.
  • took the carbs off again after the tank clean and gave them another thorough cleaning.
  • Should be noted that it's always fired first button press (No choke even)
  • Got them back on and same thing.
  • checked the spark and it's getting a nice thick blue spark on both sides.
  • pulled the exhaust and noticed a decent hole in the muffler that was hidden (pics below)
  • fired it up without the right side exhaust
  • Same problem. It just felt like right side isn't running like it should
  • Noticed drops of oil coming out of the right side exhaust with no exhaust on (This is real bad right?)
  • Got stressed out and put everything back on..
  • Fired it up again and the left plug was really black. The right side was clean. (Previous times I'd pulled the plugs they were both very black)

Now, the oil out the exhaust has me real worried. I doubt I have the experience, know how, or even tools to do any serious engine work.
This right side running poorly has to be linked I'd imagine. Or is there anything else that I haven't checked.
I have yet to do the timing because I'd like to get everything else in order before I drive it somewhere to adjust the timing (I live in an apartment and would be murdered if I was caught belching oil out as I checked my timing)

I know this is getting long but I just want to know what my next course of action should be and if I should be as worried as I currently am. Also, I know I have bigger fish to fry but should I also be worried about that hole in my exhaust?

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Most auto parts stores like Napa have a loaner program where they will loan you a tool when needed. No need to buy one just ask Napa ;D...................
 
Never run a bike without an exhaust. Even doing so for short periods of time can cause major issues.

If you have oil blow by in that cylinder, there's a very good chance you need to replace the piston rings at minimum. This will require a rehone of that cylinder as well. Worst case scenario would be that the cylinder is damaged beyond simple repair. Possible that you'd need to have both bored out and new pistons/rings (oversized) installed, but you may not have to go that far. At this point a compression test is a must.

It could also be a valve issue. Have you set the timing to spec and adjusted the valves? Do that before the compression test.

It could be a simple fix or time for a rebuild. You'll need those comp numbers and to make sure everything is to factory specs to determine that though.
 
Your going to have to get your intake and exhaust figured out before good tuning. I have a set of decent pipes I would sell you. PM me if interested... also your bike is not a 79. They only made the cb200 models for 74 75 and 76. I've owned several of them. PM me with questions on the mufflers and post more here.
 
I'd also like to mention that even if you do have to pull the jugs and replace the rings, it's not the end of the world. With the help from the folks on this site and a good repair manual, you can do it.

You would probably want to replace the valve seals as well - I know old crusty seals made my '79 CB650 burn oil something fierce. Again, not the end of the world.

Good luck!
 
have you tried running a top engine cleaner through the cylinders? by the sounds of it you may need something strong like gm top engine cleaner(if you can find it). it could be that your exhaust valve cant seal from carbon build-up. it the very least it will clean the shit out of your engine. literally.
 
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