Correct jet size for 125 carburetor being used in CD 200 engine

[saboor73]

Yes it does miss a little bit on full throttle, is this governor repairable? I was advised by the mechanic to go to Pakistan chowk to some saleemi guy.

Its not repairable don't listen to him try finding new governer

[aliatif777]

Its not repairable don't listen to him try finding new governer

Okay thanks, any substitutes? Besides the original ones?

[Synchrony]

Yes it does miss a little bit on full throttle, is this governor repairable? I was advised by the mechanic to go to Pakistan chowk to some saleemi guy.

The governor is basically a spark timing advancer, at 2000 rpm's it starts to function (advance spark) partially and at around 4000 to 5000 rpm's its supposed to be in the fully advanced position. A little gap on the spring resting terminals, worn springs, or an out of shape cam lobe on the advancer will produce a miss in between quarter throttle to full throttle.

Fortunately, the springs, cam lobe, and the scissor like parts are all replaceable, meaning if one part is worn it isn't necessary for you to replace the entire assembly, replacing the worn part with a good working one will solve the issue. Reason I explain this is because the entire governor assembly will cost you an arm, whereas replacing the damaged part will definitely save you plenty.

The saleemi shop will do what you can yourself, may or may not rip you off of price as well as part integrity, so I would rather suggest you to get the part and have the mechanic fix it right up.

[saboor73]

why don't you convert your bike to cdi

[affanashrafali]

The genuine Kiehin carb (PD33 TA) had 110 main jet for these bikes. But i believe they had bigger ventury as well. So i think using 125 carb the main jet should be little less then 110 jet.
I would suggest you can check chinese high copy of these PD33 carbs. I had that copy for 3 years with 105 jet and had no issues. Now i am using used genuine carb with 110 jet.

[aliatif777]

The genuine Kiehin carb (PD33 TA) had 110 main jet for these bikes. But i believe they had bigger ventury as well. So i think using 125 carb the main jet should be little less then 110 jet.
I would suggest you can check chinese high copy of these PD33 carbs. I had that copy for 3 years with 105 jet and had no issues. Now i am using used genuine carb with 110 jet.

For how much did you get the original carb? Are yo selling the high copy thing if you still have it?

[affanashrafali]

I bought used genuine carb for 5500, and its in perfect condition. High copy carb is in use by another road master bike.
By the way new genuine carb was available about 8 months ago at karachi and price was around 11k. Which is quite costly. And to be honest i am still not sure whther it was a genuine one or copy
Secondly advancers/governors are repairable at karachi.

[affanashrafali]

I would suggest take any of ur friends 125 carb and have some jetting done on it. Try it. If the results are good then think about getting ur own carb. As so many RMs are running on 125 carb..

[Synchrony]

The problem with a 125 carburetor is the air and fuel passages, they're simply not built to accommodate the needs of a twin cylinder engine. Jet it up for fuel for as high as you want, but that does not compensate for the air the engine will eventually need. Believe it or not, many 200's with 125 carburetors are out there to save up only on fuel. Nobody seems to care about the engine running lean and eventually self destructing itself. "Ustad jee Kilometer zyada dene chahiyay buss"

Suzuki's GS150's carburetor is another modern age option, runs perfectly smooth on a 200 after a nice tuneup. The throttle response, overall performance, and fuel mileage according to the owner is quiet a bit sweeter than the original 200 carburetor it used to have.

[aliatif777]

The problem with a 125 carburetor is the air and fuel passages, they're simply not built to accommodate the needs of a twin cylinder engine. Jet it up for fuel for as high as you want, but that does not compensate for the air the engine will eventually need. Believe it or not, many 200's with 125 carburetors are out there to save up only on fuel. Nobody seems to care about the engine running lean and eventually self destructing itself. "Ustad jee Kilometer zyada dene chahiyay buss"

Suzuki's GS150's carburetor is another modern age option, runs perfectly smooth on a 200 after a nice tuneup. The throttle response, overall performance, and fuel mileage according to the owner is quiet a bit sweeter than the original 200 carburetor it used to have.

Mileage has never been issue to me. My original Carb got stolen that's why I'm using a 125's copy in it.

[aliatif777]

I bought used genuine carb for 5500, and its in perfect condition. High copy carb is in use by another road master bike.
By the way new genuine carb was available about 8 months ago at karachi and price was around 11k. Which is quite costly. And to be honest i am still not sure whther it was a genuine one or copy
Secondly advancers/governors are repairable at karachi.

That's a very reasonable price for a genuine carburettor, can you share the source? The brand new carburettor is for 17k at karimi autos, which I'll never go for. Yeah I know its repairable here, I have to get it checked as well, can't trust the mechanics.

[affanashrafali]

I actually asked my friend at karachi to arrange that for me. I will confirm the exact place from where he bought it. I think 17k is ridiculous price even for a genuine carb :-).
Tell me one thing.. is your bike getting over heated with current carb? ( when you have a run for a good 2,3 kilometers)

[aliatif777]

I actually asked my friend at karachi to arrange that for me. I will confirm the exact place from where he bought it. I think 17k is ridiculous price even for a genuine carb :-).
Tell me one thing.. is your bike getting over heated with current carb? ( when you have a run for a good 2,3 kilometers)

Yes it is! It wasn't in the beginning.

[saboor73]

try using performance air filter of cg as it will be for performance it will allow more air

[aliatif777]

try using performance air filter of cg as it will be for performance it will allow more air

You mean those cone type air filters? I searched a lot for them, apparently they're only available for 70cc bikes.

[saboor73]

You mean those cone type air filters? I searched a lot for them, apparently they're only available for 70cc bikes.

there are some air filter for 125 ppl use them to boost performance use it as your car is small diameter it will supple lesser air in so for better combustion use performance air filter

[affanashrafali]

Yes it is! It wasn't in the beginning.

(it wasnt because you were using 200's carb)
Well in that case, please check if the plugs are more whitish in shade. As per my knowledge, the plugs should be more towards little rusty colors. If they are more white then your bike is running lean. Need to adjust petrol mixture and better do it asap.
You know actually sufficient quantity of petrol is needed to keep the bike cool as well. Lean will make your bike go heatup.
Comming to jets, Any jet equal or less then 94.5 will give you this trouble (with cg125 carb). Now this is the tricky part. You need to increase the jet size carefully, bigger jet will make bike mixture too rich. Which will make your plugs go black due to carbon until or unless you provide sufficient amount of air as well.
You can use performance filter but you can not increase the size of carburator's ventury. So that means you will have to do certain tests to find a suitable mixture setting. (do not go for cheap silver net perforamce filters untill or unless they are of K&Ns )
Tell me do you have Air Scoop installed under your bike seat? Scoop helps alot in creating air pressure in air box so that air can go to carb easily (Through under the tank and going under the seat to scoop which then redirects the air to air box). Using genuine settings/parts will help you in solving the issue easily.
Otherwise too many variables will only require too many testings to be conducted.
What i have mentioned above is my experience. I would request others to suggest you any other solutions as well.
Do let me know about your findings.

[saboor73]

(it wasnt because you were using 200's carb)
Well in that case, please check if the plugs are more whitish in shade. As per my knowledge, the plugs should be more towards little rusty colors. If they are more white then your bike is running lean. Need to adjust petrol mixture and better do it asap.
You know actually sufficient quantity of petrol is needed to keep the bike cool as well. Lean will make your bike go heatup.
Comming to jets, Any jet equal or less then 94.5 will give you this trouble (with cg125 carb). Now this is the tricky part. You need to increase the jet size carefully, bigger jet will make bike mixture too rich. Which will make your plugs go black due to carbon until or unless you provide sufficient amount of air as well.
You can use performance filter but you can not increase the size of carburator's ventury. So that means you will have to do certain tests to find a suitable mixture setting. (do not go for cheap silver net perforamce filters untill or unless they are of K&Ns )
Tell me do you have Air Scoop installed under your bike seat? Scoop helps alot in creating air pressure in air box so that air can go to carb easily (Through under the tank and going under the seat to scoop which then redirects the air to air box). Using genuine settings/parts will help you in solving the issue easily.
Otherwise too many variables will only require too many testings to be conducted.
What i have mentioned above is my experience. I would request others to suggest you any other solutions as well.
Do let me know about your findings.

he bought the bike with cg carb he was using it without air filter that becoz it was not getting over heated and you need understand whole scenario re jetting will not help him it just will give sufficient amount of petrol it but becoz of less air it will burn slowly resulting is much more over heating then before

[affanashrafali]

Oh.. i thought some one mentioned that his carb got stolen.
secondly thats exactly what i m saying if u read carefully. When i mentioned ventury effect.. it means that sufficient amount of air can not be passed through. So tunning a suitable mixture is required with that jet and air intake.

[saboor73]

Oh.. i thought some one mentioned that his carb got stolen.
secondly thats exactly what i m saying if u read carefully. When i mentioned ventury effect.. it means that sufficient amount of air can not be passed through. So tunning a suitable mixture is required with that jet and air intake.

yes he said that the carb was stolen but it was stolen when the bike was in the hand of previous owner and your are right about small venture but by using a bigger or performance air filter bike will get more air than with normal one and a ratio of fuel and air is required for combustion wouldn't be like this that give sufficient fuel and forget about sufficient air