[joshe46]

Hello all, new here and am having an issue.
So basically I'll start it up and take it for a ride and after a minute or so of riding the right cylinder will misfire and die out. Then I have to limp it home where it wont hold idle.

This started after a lot of work I just finished.
What I recently did:
Derusted the entire gas tank
Installed brand new petcock with fuel filter
Rebuilt and cleaned carbs
Tappet adjustment
New ignition points and gapped
New ignition coil and spark plugs
New battery
After all this the left cylinder will misfire and shut out. What could it be? Thanks all!

 

[Simo]

Photos of the plugs please, what height are the floats set to?

 

[joshe46]

Photos of the plugs please, what height are the floats set to?

 

[Simo]

So youre running Resistor plugs, the origin plugs had 0 resistance and a resistor in the plug cap. If youre running both the original caps and R plugs its more resistance than you want.

 

[joshe46]

So youre running Resistor plugs, the origin plugs had 0 resistance and a resistor in the plug cap. If youre running both the original caps and R plugs its more resistance than you want.

Im not running original resistors, Im running ngk 5k ohm resistors. Could this be a problem?

 

[Simo]

Yes BUT the original caps are 5k ohm same as your Replacements. Your plugs are also 5k ohm and they shouldnt be. You can use non R plugs and R caps or R plugs and non R caps

 

[Irving]

Hey man. I'm fairly new to working on these bikes too. But I think I have some good tips. Use this illustration to set float height. Note that you measure from the gasket surface with the gasket removed. From memory the cb200 gets 21 mm height. Double check that though - You should be able to download a factory service manual from doing a google search. There are a few good youtube videos out there on how to properly set float level. Your float level could be way off on that cylinder and getting too much gas. Just a thought. Take the floats out and shake them and see if there is any gas inside. If there is gas inside a float then it is leaking and you'll need to replace it. I had a leaking float on my CB200 when I bought it. A leaking float will be weighted down from the gasoline inside of it and never work right. As a consequence you'll be feeding the motor too much gasoline. Also if you haven't done a really thorough carb cleaning definitely do that. Take the carbs apart and soak everything overnight in carb cleaner. Then blow out every passageway with compressed air. Make sure every jet and passageway is totally clean and clear. Once you've got your carbs rebuilt and cleaned with floats that don't leak and the float level set you'll be in a good place and if the problem still exists you can start looking elsewhere.

 

[joshe46]

Yes BUT the original caps are 5k ohm same as your Replacements. Your plugs are also 5k ohm and they shouldnt be. You can use non R plugs and R caps or R plugs and non R caps

I didn't know this! What type of plugs should I get? I didn't know these NgK dr8 were R plugs. Any links?

 

[joshe46]

Hey man. I'm fairly new to working on these bikes too. But I think I have some good tips. Use this illustration to set float height. Note that you measure from the gasket surface with the gasket removed. From memory the cb200 gets 21 mm height. Double check that though - You should be able to download a factory service manual from doing a google search. There are a few good youtube videos out there on how to properly set float level. Your float level could be way off on that cylinder and getting too much gas. Just a thought. Take the floats out and shake them and see if there is any gas inside. If there is gas inside a float then it is leaking and you'll need to replace it. I had a leaking float on my CB200 when I bought it. A leaking float will be weighted down from the gasoline inside of it and never work right. As a consequence you'll be feeding the motor too much gasoline. Also if you haven't done a really thorough carb cleaning definitely do that. Take the carbs apart and soak everything overnight in carb cleaner. Then blow out every passageway with compressed air. Make sure every jet and passageway is totally clean and clear. Once you've got your carbs rebuilt and cleaned with floats that don't leak and the float level set you'll be in a good place and if the problem still exists you can start looking elsewhere.

View attachment 203185

Thank you! I needed that diagram. It is 21mm I believe. But carbs were just rebuilt and cleaned. However floats were not replaced. I'll check for leak. I'm sure the height is way off!

 

[joshe46]

Update: adjusted the left float and it ran a little better. Initially like before it ran strong, then started misfiring. ... now heres the thing that is baffling me, I decided to swap over the spark plugs. Left plug to right cylinder and vise versa. Upon start up the bike ran strong! And it drove strong the WHOLE time!! I took it probably 4 miles. Not a single issue with the right cylinder. The left cylinder had some audible bogging but it didnt cut or misfire badly. Only broke up at nearly redline. So no doubt I will be changing the spark plugs again. Any recommendations? But does anyone know what the hell is going on??!!


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[Simo]

Yeah your plugs are gas fouling from the float height being incorrect along with the spark being weak through the excess of Resistance in the Ht leads/plugs

 

[joshe46]

Yeah your plugs are gas fouling from the float height being incorrect along with the spark being weak through the excess of Resistance in the Ht leads/plugs

But how is it the plug doesn't work in one, but works in the other cylinder? And this was even after I adjusted float height on the right side. What plugs do you recommend that don't have resistance? Because I now need new ones!

 

[Simo]

But how is it the plug doesn't work in one, but works in the other cylinder? And this was even after I adjusted float height on the right side. What plugs do you recommend that don't have resistance? Because I now need new ones!

Electricity will take the shortest path (lowest Resistance)
to ground it can, if that path goes around the plug gap, you dont get a spark. Its easier for the electricity to flow through liquids (gasoline) than air ( your plug gap).

As ive already said the non Resistive plug code is the same code without the R
If the Resistive plug code is NGK D R 8xyz the non Resistive code is NGK D8xyz,
Youve already got the plug code its written on the plug, just remove the R from the code

 

[joshe46]

Electricity will take the shortest path (lowest Resistance)
to ground it can, if that path goes around the plug gap, you dont get a spark. Its easier for the electricity to flow through liquids (gasoline) than air ( your plug gap).

As ive already said the non Resistive plug code is the same code without the R
If the Resistive plug code is NGK D R 8xyz the non Resistive code is NGK D8xyz,
Youve already got the plug code its written on the plug, just remove the R from the code

Thank you for your help!!

 

[Irving]

Electricity will take the shortest path (lowest Resistance)
to ground it can, if that path goes around the plug gap, you dont get a spark. Its easier for the electricity to flow through liquids (gasoline) than air ( your plug gap).

As ive already said the non Resistive plug code is the same code without the R
If the Resistive plug code is NGK D R 8xyz the non Resistive code is NGK D8xyz,
Youve already got the plug code its written on the plug, just remove the R from the code

I thought these were the correct plugs for the cb200? NGK D8EA https://www.amazon.com/gp/product/B000BPLNPU

This is the first I'm hearing of the plug caps. I didn't know there was any difference for any caps. I've rebuilt my bikes motor and done all sorts of work to it but I'm still using the caps that came with it. One of them is totally blank with just the tiny tiny letters B1 and the other is a NGK LB05F 5K ohm. And I'm running NGK D8EA plugs. I guess I ought to ditch that no-name cap, huh?

There are many options for 5k ohm caps.
https://www.amazon.com/dp/B001KOL5SG
https://www.amazon.com/dp/B0018JXPWM
https://www.amazon.com/dp/B001KOI8W2
https://www.amazon.com/dp/B0018JUM0K

Just a few examples. How do I determine the best to use?

 

[Simo]

I thought these were the correct plugs for the cb200? NGK D8EA https://www.amazon.com/gp/product/B000BPLNPU

This is the first I'm hearing of the plug caps. I didn't know there was any difference for any caps. I've rebuilt my bikes motor and done all sorts of work to it but I'm still using the caps that came with it. One of them is totally blank with just the tiny tiny letters B1 and the other is a NGK LB05F 5K ohm. And I'm running NGK D8EA plugs. I guess I ought to ditch that no-name cap, huh?

There are many options for 5k ohm caps.
https://www.amazon.com/dp/B001KOL5SG
https://www.amazon.com/dp/B0018JXPWM
https://www.amazon.com/dp/B001KOI8W2
https://www.amazon.com/dp/B0018JUM0K

Just a few examples. How do I determine the best to use?

The OP's plugs are DR8ES not D8EA

You can measure the Resistance across the cap with a voltmeter it doesnt really matter whats printed on it

 

[Simo]

View attachment 204113

 

[Irving]

So what plugs are best for the CB00? DR8ES or D8EA?

 

[joshe46]

Update: adjusted float height on left carb. Installed new ngk d8ea plugs and the bike runs pretty good. No cylinders stopping no horrible misfires. Its certainly rideable but still sounds kind of boggy. And again it breaks up near 8-9k. Im thinking carbs just need better syncing.


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[Irving]

Update: adjusted float height on left carb. Installed new ngk d8ea plugs and the bike runs pretty good. No cylinders stopping no horrible misfires. Its certainly rideable but still sounds kind of boggy. And again it breaks up near 8-9k. Im thinking carbs just need better syncing.


Sent from my iPhone using Tapatalk

What mufflers and air filters are you using? I just changed to the CL200 #95 main jets and it nearly solved my problem, which sounds very similar to yours. The stock CB200 mains are #88. The smaller mufflers on the bike seem to have made the change necessary. I was also having extreme breakup and hesitation in the 7 to 9k range. It's now fixed. But will still die on full throttle from idle. Which isn't too big a deal.