Why Does My Honda CL200 Only Run With Very Advanced Timing?

Classic5

New Member
Hey All,

I'm working on a CL200 that I'm at my wit's end with. After working on it all summer and not being able to get it to run right, I've stumbled across a solution, but it seems like a dangerous one. The bike starts fine and runs better than it has before, but only if I severely advance the ignition timing. I know that this can cause problems so I'm really wanting to have it run well at factory specs if at all possible. Does anyone know why the bike is doing this?

Here is what I've done to the bike:
  • Bored out cylinders .50mm and fitted with the appropriate pistons&rings
  • Set the cam chain tensioner
  • Set the valve clearance to a loose .05 MM
  • Used a test light (not a timing light) to set the points to not only have the factory spec max clearance but to fire right at the F mark
  • Got a new "snappy" spark advance mechanism
  • Set A/F mixture screw to 5/8ths turn out +- 1/8th
  • Pulled some hair out
  • Cried a little bit.....

I haven't checked it with a timing light yet to see where it's ACTUALLY firing at, but I plan on doing that in the next few days.

Any ideas on what to check/try would be GREATLY appreciated.

Thank you!
 

Sonreir

Oregon
Before doing anything else with the timing, please check compression. Low compression is a common reason for requiring advanced timing. If compression is low, we can start troubleshooting why that might be.
 

adventurco

Nick Ol' Eye
DTT BOTM WINNER
What do you mean "severely advanced timing?" If you're saying that you set the points to the max gap and it runs, I don't see any problem with that.

Check it with a timing light as that is actually going to tell you what is going on. When the bikes running at about 3500 rpm you want to make sure the hash mark lines up in the middle of the two advance marks on the rotor.

If its way far out, then something is up with your advance mechanism either reversed or..?

Edit: Its a good idea to check compression as Sonrier stated. Considering you had the cylinders bored out I hope that you at least checked to make sure the valve seats were sealing properly.
 

Classic5

New Member
Hey Sonrier,

In addition to checking the timing with a timing light I'm planning on borrowing a gauge to see what the compression is, so thanks for that tip!

Just for my own knowledge base, do you know why the timing needs to be advanced in order for it to run when the compression is low? I would think just the opposite would be true but I'm fairly new to the art of the engine.

I'll report back once I get some more info to hopefully provide an answer to this question.

Thanks!
 

Sonreir

Oregon
You need a certain amount of cylinder pressure to ensure your engine runs. That cylinder pressure is usually provided by the burning of the fuel/air mix (hot gases expand and that expansion is what provides you with usable power). The reason the spark fires before top dead center is that it takes a little while (split second, but still a consideration) for the fuel to burn inside the cylinder. This is called flame propagation. So after the spark fires, there's a small delay before cylinder pressures build. Ideally, peak cylinder pressure is at around 14° ATDC. If it comes in later than that, you're losing power.

Anyway... the point I was coming around to making is that the pressure in the cylinder that comes from the expanding gases from burning the fuel works in conjunction with the compression already provided by the rising piston. So if you start with low compression, then you're still lower than you need to be during the flame propagation period. You can get an engine with poor compression to run by advancing the timing and causing the spark to fire sooner. This gives the flame more time to propagate while the piston is still rising and creates enough total compression in the cylinder to keep the engine running.
 

Classic5

New Member
Hey All,

I checked the pressure in each cylinder today and got 115 in both. Considering I just had the cylinders bored and put new rings and pistons in, new gaskets, made sure the valve clearance and timing is to spec, I'm thinking it must be the valve seats themselves. Would you agree?

I was going to call up Moto Tech in OH and ship him my head to inspect/fix.

Let me know if you have any other advice!
 

Classic5

New Member
One other thing....

I finished taking the engine apart and noticed some wear marks (vertical streaks) in the fresh cylinder walls. Is that normal? Or should I be worried. The don't look like gouges, but are noticible without too much effort.
 

teazer

Active Member
DTT BOTM WINNER
It takes a while for pistons and rings to bed in and for compression to come up. When you tested compression were the carbs wide open and did you kick it over 5 -10 times until it stopped rising?

If you have the head off, if the cam is still fitted, back off the tappets and turn it over until one pair of valves are closed and then turn it upside down and pour thin oil or kerosene or gasolene into the head and see f it leaks out or weeps out of the ports. If it does, the valves and seats need to be cut and if not, the head is fine.

When you reassemble the motor take time to be sure that teh cam is correctly timed and then that the ignition is correctly timed.
 

Classic5

New Member
Hey Teazer,

Thanks for the tip on how to check the valve seals. I'll definitely itely give those a test!

I definitely had the throttle wide open and ran the starter till the guage wouldn't climb any higher. Should I have specifically kicked it instead of using the starter?

As far as the rings seating is concerned, would you expect them to improve their seal enough to take it from 115psi up to 160 or whatever it's supposed to be? That just seemed like such a long way to go I assumed that the valves must be leaking.

Thanks!
 

Classic5

New Member
For that matter, I can find lots of forums where people say that you need to seat the rings and that psi will go up after, but nobody ever expands on what a typical rebuild psi should be and then what it can be expected to go up to once the rings seat. Is it because there is so much variance in the process or is it something else?

Thanks!
 

adventurco

Nick Ol' Eye
DTT BOTM WINNER
Classic5 said:
Got a new "snappy" spark advance mechanism
Ignoring the compression for the moment - 115 psi on both cylinders should be enough for it to run until the rings bed in - is this a "new" aftermarket or new used advance mechanism? Is it installed correctly? The cam lobe can be installed 180 degrees out and really screw things up.
 

Classic5

New Member
Hey advCo,

This was a new OEM advance mechanism that appeared to have never been installed before.

As far as the cam lobe being 180° out of sync, I'm fairly confident that I installed the cam shaft correctly according to the manual. Placing the "spark advancer knock pin facing upward" and having the lines on the cam sprocket in line with the head while keeping the crankshaft aligned with with the "T" mark. I believe the advancer mechanism itself only has one slot for the pin to fit into which would make it impossible for that to get installed incorrectly.

Am I correct in thinking the "spark advancer knock pin" is the pin that makes the advancer mechanism spin on the very end of the camshaft? or is it a small flange further in towards the center that doesn't seem to operate anything?

Thanks!
 

Sonreir

Oregon
Only a single point with a dual tower coil on a CB200 (it's a 360° engine and not 180° engine), so the advancer can't ever be 180° out.
 

Classic5

New Member
Hey All,

So after reading the post by AdvCo about how 115psi should be enough to get it running, I decided to look elsewhere for issues that might be causing my problems. I eventually found that the right side carb (although properly set to the spec. float height) was not letting gas into the bowl! I still can't figure out why, but I think the floats are resting on the bottom or sides of the bowl or something and closing off the gas intake. I realize this makes it sound like it's actually NOT properly set, but I was very diligent in setting them and the left side carb is exactly the same and runs pretty well. I took off the carb and soaked it in carb dip for a few hours, blew carb cleaner and compressed air through all the holes and made sure it was clean and got no change in performance until I raised the float level(made it so that the gas level in the bowl would be higher) and then the right cylinder engaged but poorly. I've tried raising and lowering the level to try and improve the performance, but didn't have great results.

This makes me think that either the float is messed up/ not the right one for the carb OR the carb is not actually the right one for the CL200? The float does not look abused or bent in a way that would cause this. I'm planning on swapping the components in the carbs tonight to see if the symptoms switch with it, but wanted to update you all on where I'm at with this. Do you have any advice?

Also, I currently have a synthetic oil in the engine. Should I switch to a conventional oil for seating the rings?

Thanks again for all of your help. I really appreciate you guys sharing your years of knowledge with a rookie like me.
 

adventurco

Nick Ol' Eye
DTT BOTM WINNER
Take the offending float out and place it in a cup of water or fuel and make sure it is buoyant. Leave it there for 24 hours or so just to be sure. If it sinks at all you will probably want to replace it.

Make sure that your float needle is not binding in the seat. If there is a noticeable depression in the pointed section at the bottom, it could be causing it to bind up.

Edit: Its unlikely, but there could be some constriction in the petcock. Attach some fuel hoses to the 2 barbs on the tank and turn the fuel on (with a fairly full tank). Make sure that there's enough fuel coming out of both sides. If not, there could be some crap in the screen or in the tank blocking good flow to the carbs.
Regarding the oil, you definitely don't want to run synthetic with a wet clutch. It will slip. I like to run Rotella 15-40w but any motorcycle oil should be pretty sufficient (don't use regular car oil).
 

jpmobius

where does this go?
DTT BOTM WINNER
When you check the petcock, if you only get fuel from one outlet, close it off with your finger and see if it makes fuel come out of the other. If it does, the petcock is fine. Often petcocks will only free flow fuel from one outlet at a time. Not too sure why this is, but don't worry about it. Also, if you have clear fuel lines, don't worry if there is a lot of air in them. As long as there is fuel always above the inlet to the carb, all is well. Very unlikely the petcock is your issue - either the problem is obvious, or the bike runs lean temporarily if you run it hard due to insufficient fuel flow. I am also a big promoter of Shell Rotel oil.
 

pidjones

Active Member
And, Rotella T6 is full synthetic without the friction modifiers that cause wet clutch slipage, and safe to use in motorcycles. Another thing to check on the carb is that the float valves (and seats) are identical. Setting float height by gravity requires that you turn the carb such that the float tang just closes the valve without depressing any plungers on the valve. The float should be full free to move. After replacing the bowl you should be able to hear the float moving as you tilt the carb.
 

Classic5

New Member
Hey All,

Checking back in after the weekend of tinkering. I swapped the floats and bowls on the bike and suddenly it started running! I'm convinced that nothing gives your brain endorphins like a motorcycle kicking to life.

There are still some issues that I have to work out though, as the right side continues to have difficulty idling as smoothly or consistently as the left side. Also, I'm having a strange issue when driving it too, where it'll start to bog down and eventually die after a short while of consistent medium speed (40mph-ish, I haven't tried going any faster yet). I'll let the bike sit for 30 seconds and then I can start it back up again and drive for a little while further before the issue happens again. I'm assuming this is being caused by the carbs not being able to keep up with the fuel demands but would love to hear your takes on it!

After running it around the neighborhood a little bit, I re-set the cam-chain tensioner, adjusted the valves(0.05mm), set the timing, and took off the offending carb, soaked in cleaner for 6 hours, sprayed carb cleaner through the passageways, shot compressed air through it again and used a Q-Tip with some toothpaste in a drill to polish the inside of the float seat to make sure that the valve isn't sticking. If I soak that carb any longer, it'll just dissolve completely. I'm convinced the passageways are clean.

I'm thinking it's still an issue with the float, gas level, and valve that I need to figure out as the fuel flows freely through both sides of the petcock and through the fuel filters and lines without issue. Thank you again for your help!
 

adventurco

Nick Ol' Eye
DTT BOTM WINNER
Classic5 said:
Hey All,

Checking back in after the weekend of tinkering. I swapped the floats and bowls on the bike and suddenly it started running! I'm convinced that nothing gives your brain endorphins like a motorcycle kicking to life.

There are still some issues that I have to work out though, as the right side continues to have difficulty idling as smoothly or consistently as the left side. Also, I'm having a strange issue when driving it too, where it'll start to bog down and eventually die after a short while of consistent medium speed (40mph-ish, I haven't tried going any faster yet). I'll let the bike sit for 30 seconds and then I can start it back up again and drive for a little while further before the issue happens again. I'm assuming this is being caused by the carbs not being able to keep up with the fuel demands but would love to hear your takes on it!

After running it around the neighborhood a little bit, I re-set the cam-chain tensioner, adjusted the valves(0.05mm), set the timing, and took off the offending carb, soaked in cleaner for 6 hours, sprayed carb cleaner through the passageways, shot compressed air through it again and used a Q-Tip with some toothpaste in a drill to polish the inside of the float seat to make sure that the valve isn't sticking. If I soak that carb any longer, it'll just dissolve completely. I'm convinced the passageways are clean.

I'm thinking it's still an issue with the float, gas level, and valve that I need to figure out as the fuel flows freely through both sides of the petcock and through the fuel filters and lines without issue. Thank you again for your help!
Did you test the floats making sure they are 100% buoyant like I said in an earlier post?

Regarding the stalling, I'm willing to bet its either your gas cap not venting correctly or coil breaking down while hot, then being ok when its cooled down a bit. I'd check the gas cap vent first. An easy way to test it is to keep the fuel tank popped open, take your normal ride and then see if it stalls when it normally would. If not, then you know thats your issue and you can try blowing/cleaning it out.
 
Top Bottom