Honda Twins banner
1 - 9 of 9 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter · #1 ·
Gentlemen, I need help from the experts here.
I have a 1975 CB200T which I got last year. I have solved most of the issues however I am stumped now.
It appears to me that It is running too rich do to carbon fouling of the plugs. They are not wet with gas, just black with carbon.
Also, the bike will not idle at all. It seems to run well as I ride down the road but dies below 2K rpm.

The bike starts up on the 1st or 2nd kick but here is what the plugs looked like this morning. Spark plug Auto part Automotive engine part Automotive ignition part


I replaced the plugs with new and put the C clip on the needles to the top notch and it seemed to run better. I rode for about 5 minutes before it seemed to start having issues. After 10 Minutes this is what the plugs looked like.
Spark plug Auto part Automotive engine part Automotive ignition part
Spark plug Automotive ignition part Auto part Automotive engine part


I have cleaned the carbs thoroughly and ran brushes in all channels. I set each float to 21mm from the lower lip of the carb.
What am I missing?
Land vehicle Vehicle Motorcycle Motor vehicle Automotive tire
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #2 ·
One thing I missed was that I currently am running without air filters. The bike came with some crappy ebay filters which was starting to crumble with age. So I removed them. I am looking for a suitable replacement.
 

·
Registered
Joined
·
328 Posts
Not idling with air filters removed is very common.

Don't try to read the plugs until you give it a good 20 mile ride. I was chasing ghost forever while setting timing and etc before I learned that. It has to really RIDE to get that clean chocolate brown you want.

That said, those look even worse than mine ever did while setting timing and carb balancing.

Sent from my SM-G930V using Tapatalk
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #4 ·
The bike came with the air boxes missing. I am looking for a replacement which fits. I would prefer the original air box but I have not found them at a reasonable price, so I am looking for an aftermarket which will fit. I am open to suggestions from someone who had success with one of these. I am thinking about a UNI filter like this one. Automotive exhaust Muffler Auto part Material property Exhaust system
 

·
Registered
Joined
·
111 Posts
A lot of Hondas don't like running without the stock airbox/intake setup.
Getting something else working well can be a painful, slow process but a lot of folks HAVE done it.
Or so they say... ;)

I am not one of those - I have always used stock intakes.

One thing I have just started using recently is Startron Fuel Enzyme Treatment- Star Tron Enzyme Fuel Treatment

My 450 has been doing well once warmed up but my 750 has had all kinds of idle issues and I KNEW the damn carbs were pretty much right.
First time I used the enzyme stuff was the ride home from work- about 50 miles.
Idle was up at 4 grand when I got near the house.
Set it down to 1200-1500 range and it has been perfect since.
And my plugs look about right now too, and they used to start fouling and need to be cleaned every 1000 miles or so.

Not saying it will replace the proper intake, but some of that stuff my help.
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #7 ·
Update on my carbon foul issue. I originally timed my bike with a timing light. This was very difficult as the bike does not idle and the oil is spraying out every where!
I found an excellent Youtube video on setting the timing with a test light for a CB350. I was able to do this for my CB200T and it now runs like a dream! However the plugs still have some carbon fouling (not as bad as before).
I tested with a new NGK D8EA spark plug on one side and a hotter NGK D7EA plug on the other. No noticeable difference on the fouling.
Any suggestions on leaning out the fuel would be helpful.
I included a link to the timing video here.
 

·
Registered
Joined
·
6,495 Posts
The slide needle position can also be altered on CB200.
CB200 normally has 88 main jets.
Manipulating both at the same time can sometimes be counter-intuitive, depends on where in the rpm range you are rich.
Sometimes you use a larger jet, but drop the needle - opposite what you might think at first.

Float height also matters, a LOT.
 
1 - 9 of 9 Posts
Top