CB200 carb issues

[Sesman]

Hi, K2/K6. The good news is it’s not electronics, which is definitely one for Ash. I had my fill of PN junctions, K transforms, Active front ends/power electronics, Fourier series and the like some 30 years ago😳

[Sesman]

I thought I was dylysic, but didn’t read anything into it. Apologies but it’s the landlords, hic.

That Timothy Taylor has a lot to answer for.😁😁😁

Indeed Ted. I’ve recovered now thankfully…..it was a rather heavy T Time session. Never, never post if you have had a few.🫣

[McCabe-Thiele (Ted)]

Hi, K2/K6. Fourier series and the like some 30 years ago😳

That rings a very distant bell (53 years for me ) Fourier Analysis it's filed in my brain with Frobenious Method.

[SteveD CB500K0]

Luckily those of us in the electronic engineering school split from the mathematicians just before the fast Fourier transforms.

Went straight to pn junctions.

The shared first year, while “boring” at the time, did teach us the basics of fluid dynamics, materials science etc.


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[McCabe-Thiele (Ted)]

Don't want to hijack the thread but........ I never did find a use for imaginary numbers - imaginary friend however ? lol

[Sesman]

Goodness, a+jb. I love em and use them a lot in my work. I once used them to demonstrate system fault calculations and the consultant engineer who reviewed them had the pass them as he didn’t understand the maths…remarkable.😳

[Sesman]

Back on topic, was the misfire, holding back problem solved?

[Oddjob]

We don't know, he died of boredom about 14 posts ago 

[SteveD CB500K0]

I don’t drink tea but I did spit my coffee at that.


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[Johnwebley]

Back on topic, was the misfire, holding back problem solved?

  not quite died yet,its been cold,so I have left it until it warms up.

BUT,thinking  ,at 6,000 rpm itis generating 100 sparks per second,using the 4.7ohm coil ,

 is that enough to make the coil refresh??
infact,at the red line of 9K,it should be having 150  bangs a second,.

I know it was hopeless  with a wide contact gap,reducing it to 12thou  certainly improved  the general running,but not increased  how high it revs.

does anyone know the spec of the original coil?

no details on either  DSS or  CMSNL,Wemoto  give 4.7 for one,and 4.2 for another.



 HELP

[McCabe-Thiele (Ted)]

Going back on topic what is your ownership history with this bike - have you ever had it run at say 8,500 rpm.

You have started much as I would have looking at air intake fueling & then sparking.
Are the coils on your CB 200 like my 400 with the leads as part of the coil.

My other thought making quite a few assumptions such as  you have enough fuel flow into the carbs with the right jets etc - is what about the other end - could the exhuast system be blocked up?

Are you happy with the condensers as well as the coils ability to produce the sparks fast enough ?

[Sesman]

We don't know, he died of boredom about 14 posts ago 

😁😁😁😁😁

[Sesman]

Yes, it’s sufficient time for it to ‘charge up’. Points problem, condenser problem anybody?

[Johnwebley]

Going back on topic what is your ownership history with this bike - have you ever had it run at say 8,500 rpm.

You have started much as I would have looking at air intake fueling & then sparking.
Are the coils on your CB 200 like my 400 with the leads as part of the coil.

My other thought making quite a few assumptions such as  you have enough fuel flow into the carbs with the right jets etc - is what about the other end - could the exhuast system be blocked up?

Are you happy with the condensers as well as the coils ability to produce the sparks fast enough ?

 when I first got it running,it ran  up to the red line ok,

slight fluffing,but the air cleaners were original and caked with dirt.

it had a after market coil,smaller than standard,so only had a single mounting point,

since trying to put it back to standard,its had a  coil from Wemoto,correct size,
new capacitor,original points,

it uses a single points,and Capacitor on a twin lobe cam

[McCabe-Thiele (Ted)]

With  that updated information the coil change  looks to be the part that caused the loss of rpm.

Sounds daft but first thing I would do is fit the old parts back on - if it returns to working the answer should be in the coil.

Assuming you have the same make & grade of spark plugs & caps. If you have fitted new plugs might be worth trying it with the old ones fitted.
Just me thinking out loud John sorry if it's obvious twaddle.