guys,

checked my plug yesterday, i found out that it was too light and not rusty brown as it should be.
i turned the screw fully closed clockwise, and found out that the stock setting was set to about 3/4 counterclockwise from fully closed.

how many turns counter-clockwise from fully closed should our bikes be set?

i'm experiencing frequent backfire on my bike.

thanks.

try to adjust it again...and see if the plugs ok na...if you did some mod to your mufflers and or your airbox, definitely magbabago setting ng air/fuel mixture.

I need help rin in adjusting the A/F mixture ng z200 ko...

Yung sa akin naman it's soothy black, napaka-itim naman and 1 day of normal driving lang yung takbo ko ganon na agad kailangan na agad linisin yung spark plug para di mahirap magstart. A/F mixture lang ba problem nito? If yes how do i adjust this? Nabasa ko kasi sa ibang thread na dalawa yung adjustment nito isa for the gas and isa for the air. I think yung gas ata yung malapit sa idle up right? yung tinutukoy ni pranix sa post nya sa taas? If yes saan naman yung para sa air?

Need help pls... thanks!

yung air nasa ilalaim...but i would suggest that you bring your bike over the nearest service center and have it checked....di normal yung mga problems you've mentioned....

help naman mga bro, experience ko sa mc ko ang lakas ng backfire nakakagulat try ko adjust ng A/F mixture sa carb nawala ang backfire kaso namamatay ang engine kung idle lang...mali kaya ang mixture:rolleyes: anu ba ang tamang mixture mga bro:?

for your info:

if your engine is still stock, factory setting of your A/F mixture is approx. 2-1/2 turns from close position. that is start from close position (rich mixture) then let some air in by making 2 full turns and 1 half turn. if you further want to make it leaner then you may start from this setting and trim your A/F mixture.

if somebody still ask if a change of plug is still stock? yes, your engine is still stock even you change your ignition system. only changes to the engine, exhaust system and air intake will be considered as modified in this topic.

Hi guys!

May I also share my technique on adjusting our PZ27 carbs, which unfortunately I have just learned... only recently.

The technique is based on the Stoichiometric Ratio, which is 14.7:1 or 14.7 air is to 1 fuel (read this (http://en.wikipedia.org/wiki/Stoichiometric_air_ratio)). That is for every 14.7cc of air only 1cc of fuel is required to attain the highest combustibility of gasoline w/o being lean or rich. Meaning it is the finest tune for your Motorcycle engine EVER. Yup! It sounded as if you need to have a lot of measuring device to achieve this on your carb. In fact, it is the Stoichiometric Ratio that is being maintained in EFI or fuel injection systems where a lot of sensors is used to tell a computer how to attain the proper air-to-fuel ratio while running in different environmental conditions and loads.

Unfortunately with our carbs, we don't have a computer and sensors to accurately attain this fine A/F ratio. But with the technique that I have mentioned, we are blessed with the simple adjustment screws that we have on our PZ27 carbs: the idle-speed adjust screw and the mixture adjust screw to achieve Stoichiometric Ratio (Pls refer na lang from the z200 parts manual found on the XPhil website for the proper locations of this screws. Anyway, most of the forumers in this thread knows it already.) The mixture adjust screw is also called Air screw in other sites, and this is what we need to focus on. To attain the Stoichiometric ratio, you don't need to know which way with the mixture screw is going lean and which way is going rich. You don't even need to turn the mixture screw to full close, where it is risky for the mixture screw gasket and spring to get damaged. Just do the following:

1. START THE ENGINE AND LET IT WARM UP to operational temperature (you may ride it around your barangay or subdivision for a few minutes also). Do not adjust carburetor when engine is cold.
2. With the engine running at idle speed. turn mixture adjust screw slowly clockwise (turning in) by 1/4 increments, until engine falters. Stop at this point. Now turn screw counter-clockwise by 1/4 increments until the engine falters again. But this time, count the number of turns.
Note: The PZ27 mixture screw is quite small and facing downward, that a proper precision flat-head screw is needed. It should be short enough so you don't get burned by the hot engine.
3. Divide the number of turns by 2, and take note of the quotient.
4. Turn screw clockwise by 1/4 increments again, and count until you reach the quotient. This is exactly halfway between your first and second positions, and the optimum setting on your carburetor.
5. After mixture adjustments have been made, idle speed may need to be adjusted to its user's manual prescribed rpm for idling.

The main idea of this 5-step procedure is to find the Stoichometric ratio between the leanest and richest operating condition of the carburetor, without using any measuring device. It is based on the fact that, engines run poorly when too lean, and runs poorly when too rich. So the mid-way between this two points (lean and rich) must be the ideal A/F ratio.

But wait... this procedure only works if both your carburetor and engine don't have damages. It is best to have them fixed first before doing the tuning. Anyway, you can find out during the procedure if there's something wrong with your carb or engine. Visit this site: http://www.off-road.com/atv/kidskorner/idleadjust.html

FINAL WORD: Adjusting carbs on our own is really not advised by mechanics because of the dangers mentioned above, and they thought we can't get well informed enough to go around these dangers. Well, let's understand them. But when you have modifications on your exhaust pipe and airfilter, change to split-fire cable and plug, you will need to re-tune your carb. So it is nice that you know the proper how-to, instead of taking the trouble of going to the mechanic and pay for his services for the simple re-tune. I personally believe, that the procedures I mentioned here are quite safe for your carburetor and engine, as long as it is followed properly to the letter.

Zongshen 250cc Info, same din po ito ng Z250CC

-- Dual front disk brakes
-- Gas gauge/ ABS brakes
-- Light weight-design

The Zongshen GS250 features a durable light-weight design, wide-range single headlight, front & rear disk brakes, dual rear-view mirrors, ABS rear braking system and a engine protective cover.
The GS250, a stylish light-weight motorcycle perfect for beginners as well as motorcycle veterans.

SPECS:

Engine
Displacement - 230cc 4 Stroke
Cooling - Air-cooling
Transmission - Chain
Ignition - C.D.I.
Starter - Electric/Kick
Max Speed - 80 mph

Chassis
Brakes/Front - Dual Disk
Brakes/Rear - Disk
Wheel Type - Alloy
Ground Clearance - 5.7

Dimensions/Other
Length - 79 in.
Width - 30 in.
Height - 43 in.
Net Weight - 366 lbs.
Max Load - 331 lbs.
Wheelbase - 54.6 in.
Fuel Economy - 130 mpg
Fuel Capacity - 1.3 gallons

Clik the link:
http://www.zongshenamerica.com/products.php?type=Motorcycles&id=001

BTW: just a follow-up to my previous post. You must have a fall-back or base to go back to, before going through the procedure.

It is best, while turning the mixture screw for the first time in Step 1, that you must count the 1/4 turn increments from its original position. So that in case you can't find the falter point, you can just return to its original position through the number of turns that you have made.

If you don't know how to re-jet, have a mechanic re-jet your carb. It's maybe the reason why you can't find the the falter point. There is also a possibility that you need to replace your pilot jet as mentioned in http://www.off-road.com/atv/kidskorner/idleadjust.html

Or you just simply liked the original settings, and you wish to go back to it.

this post is off-topic
modz please move topic to the z250 thread.

Zongshen 250cc Info, same din po ito ng Z250CC

-- Dual front disk brakes
-- Gas gauge/ ABS brakes
-- Light weight-design

The Zongshen GS250 features a durable light-weight design, wide-range single headlight, front & rear disk brakes, dual rear-view mirrors, ABS rear braking system and a engine protective cover.
The GS250, a stylish light-weight motorcycle perfect for beginners as well as motorcycle veterans.

SPECS:

Engine
Displacement - 230cc 4 Stroke
Cooling - Air-cooling
Transmission - Chain
Ignition - C.D.I.
Starter - Electric/Kick
Max Speed - 80 mph

Chassis
Brakes/Front - Dual Disk
Brakes/Rear - Disk
Wheel Type - Alloy
Ground Clearance - 5.7

Dimensions/Other
Length - 79 in.
Width - 30 in.
Height - 43 in.
Net Weight - 366 lbs.
Max Load - 331 lbs.
Wheelbase - 54.6 in.
Fuel Economy - 130 mpg
Fuel Capacity - 1.3 gallons

Clik the link:
http://www.zongshenamerica.com/products.php?type=Motorcycles&id=001

thanks for the info sir blueknyght, thats a big help to DIY'ers

thanks for the info sir blueknyght, thats a big help to DIY'ers

you're all welcome, sir! :banana:

i benefited a lot from all the sharings here, and its time that I give my share also... esp. when its something that is proven by experience... anyway, they're all just from the web, I'm just like a relay station w/ quality control ;)

a quick question again... is backfire caused by wrong setting of A/F mix?
or meron pang ibang reason bakit nagbbackfire...

I checked the plug naman and it's perfectly golden brown.

leak on the muffler could be one thing.

a quick question again... is backfire caused by wrong setting of A/F mix?
or meron pang ibang reason bakit nagbbackfire...

I checked the plug naman and it's perfectly golden brown.

check mo rin sir sa intake and exhaust side bka may leaks

ok thanks for the inputs angel z200 and jolads.

a quick question again... is backfire caused by wrong setting of A/F mix?
or meron pang ibang reason bakit nagbbackfire...

I checked the plug naman and it's perfectly golden brown.

A/F mix can also be one reason of backfires... actually, there are so many possible causes for a backfire, you can research about backfires from wikipedia, and other motor sports sites on the web.

If you are sure your engine is quite new, and there's no doubt there are any damages or defects from the carb and the engine, definitely it's on the A/F mixture. According to what I've read, backfires are caused by too little fuel and a too lean A/F setting. You may try the procedure I mentioned on this thread to correct it.

wow ma try nga ito! i use to have a back fire on my z2 but when i adjusted the a/f to rich state,i got less. ill try setting it to this mode. hehehehhehehehe...

wish me luck bro's!

thanks. i'll try it out. :)

very informative blueknyght ... :D

... another thing that causes backfires that we often overlook are mga singaw sa pipes ... :D baka may tanggal na rivet or may singaw ang pipe or connections .. :D

very informative blueknyght ... :D

... another thing that causes backfires that we often overlook are mga singaw sa pipes ... :D baka may tanggal na rivet or may singaw ang pipe or connections .. :D

follow-up question ge...
how to spot leaks on the exhaust system? use water? or detergent? :?

no actually maramdaman mo yan when you rev you bike .. check mo yung mga may connections sa pipe mo usualy don sa may end cans or rivets na maluluwag .. or yuhng iba pag sumemplang may kuping ang pipe HTH... :D

Hi guys!

May I also share my technique on adjusting our PZ27 carbs, which unfortunately I have just learned... only recently.

The technique is based on the Stoichiometric Ratio, which is 14.7:1 or 14.7 air is to 1 fuel (read this (http://en.wikipedia.org/wiki/Stoichiometric_air_ratio)). That is for every 14.7cc of air only 1cc of fuel is required to attain the highest combustibility of gasoline w/o being lean or rich. Meaning it is the finest tune for your Motorcycle engine EVER. Yup! It sounded as if you need to have a lot of measuring device to achieve this on your carb. In fact, it is the Stoichiometric Ratio that is being maintained in EFI or fuel injection systems where a lot of sensors is used to tell a computer how to attain the proper air-to-fuel ratio while running in different environmental conditions and loads.

Unfortunately with our carbs, we don't have a computer and sensors to accurately attain this fine A/F ratio. But with the technique that I have mentioned, we are blessed with the simple adjustment screws that we have on our PZ27 carbs: the idle-speed adjust screw and the mixture adjust screw to achieve Stoichiometric Ratio (Pls refer na lang from the z200 parts manual found on the XPhil website for the proper locations of this screws. Anyway, most of the forumers in this thread knows it already.) The mixture adjust screw is also called Air screw in other sites, and this is what we need to focus on. To attain the Stoichiometric ratio, you don't need to know which way with the mixture screw is going lean and which way is going rich. You don't even need to turn the mixture screw to full close, where it is risky for the mixture screw gasket and spring to get damaged. Just do the following:

1. START THE ENGINE AND LET IT WARM UP to operational temperature (you may ride it around your barangay or subdivision for a few minutes also). Do not adjust carburetor when engine is cold.
2. With the engine running at idle speed. turn mixture adjust screw slowly clockwise (turning in) by 1/4 increments, until engine falters. Stop at this point. Now turn screw counter-clockwise by 1/4 increments until the engine falters again. But this time, count the number of turns.
Note: The PZ27 mixture screw is quite small and facing downward, that a proper precision flat-head screw is needed. It should be short enough so you don't get burned by the hot engine.
3. Divide the number of turns by 2, and take note of the quotient.
4. Turn screw clockwise by 1/4 increments again, and count until you reach the quotient. This is exactly halfway between your first and second positions, and the optimum setting on your carburetor.
5. After mixture adjustments have been made, idle speed may need to be adjusted to its user's manual prescribed rpm for idling.

The main idea of this 5-step procedure is to find the Stoichometric ratio between the leanest and richest operating condition of the carburetor, without using any measuring device. It is based on the fact that, engines run poorly when too lean, and runs poorly when too rich. So the mid-way between this two points (lean and rich) must be the ideal A/F ratio.

But wait... this procedure only works if both your carburetor and engine don't have damages. It is best to have them fixed first before doing the tuning. Anyway, you can find out during the procedure if there's something wrong with your carb or engine. Visit this site: http://www.off-road.com/atv/kidskorner/idleadjust.html

FINAL WORD: Adjusting carbs on our own is really not advised by mechanics because of the dangers mentioned above, and they thought we can't get well informed enough to go around these dangers. Well, let's understand them. But when you have modifications on your exhaust pipe and airfilter, change to split-fire cable and plug, you will need to re-tune your carb. So it is nice that you know the proper how-to, instead of taking the trouble of going to the mechanic and pay for his services for the simple re-tune. I personally believe, that the procedures I mentioned here are quite safe for your carburetor and engine, as long as it is followed properly to the letter.

wow...:banana:
of all the A/F adjustments i've read to this thread and any other threads, this one is i think the most informative so far...thanks for this very nice idea sir. maybe you can add...just to make sure you got the right mixture, check also the SP color...ride safe...

mga sir sabi sa akin ng mekaniko ng probikes minsan cause ng bike fire eh kung nagpalit ka ng muffler yung whole set po, tapos yung isa pa daw factor is singaw nga sa pipe like what sir g said, tapos finally is masyadong malaki ang opening ng muffler mo like what im experiencing sa z200 ko kasi yung muffler na nakakabit sa z200 is pang kotse. :)

@ sir blueknyght
should i turn the mixture screw from a CLOSED setting to the clockwise 1/4 increment or should we start on normal idle?

@ sir blueknyght
should i turn the mixture screw from a CLOSED setting to the clockwise 1/4 increment or should we start on normal idle?

turning of the mixture screw can start from your present settings. it's usually the settings made by the service center mechanic after a tune-up (by simply listening to the engine sound = not reliable).

just watch out for the 2 faltering points (observe and feel it). then get the middle best setting. i tested the turns of my A/F mix settings for my z200 to be seven-and-a-half (7.5) 1/4 turns from fully closed.

and pls remember, do not do any adjustments on your carb if there's something wrong with your engine, carb and mufflers. that also includes high valve clearances (loud typewriter noise from the cylinder head), pa-adjust ka muna ng valve clearance b4 you do any carb adjustments.

good luck bro.

wow...:banana:
of all the A/F adjustments i've read to this thread and any other threads, this one is i think the most informative so far...thanks for this very nice idea sir. maybe you can add...just to make sure you got the right mixture, check also the SP color...ride safe...

thanx sir. not my idea really... i got it from the internet. i think i have included a hyperlink on my long "info" post to the site where i got it, for reference.

good point on the sparkplug color, sir. our user's manual recommends BROWN color. that's the color of my SP right now, using the mixture adjustment that i've recommended. plus, my SP ground strap is cleaner, you won't need to sandpaper it whenever you clean it. there's just some tiny white ash deposits that you can just wipe w/ a rag.

the A/F adjustment i recommended is only for good idling and good A/F ratio from close to 1/4 opening of the throttle.

we should also learn to read from the sparkplug the A/F mix when we open the throttle from 1/4 to full throttle opening. correcting A/F for this will require rejetting or adjusments on the fuel pump on the side of our carb... not on the mix screw.

mga sir sabi sa akin ng mekaniko ng probikes minsan cause ng bike fire eh kung nagpalit ka ng muffler yung whole set po, tapos yung isa pa daw factor is singaw nga sa pipe like what sir g said, tapos finally is masyadong malaki ang opening ng muffler mo like what im experiencing sa z200 ko kasi yung muffler na nakakabit sa z200 is pang kotse. :)

yes sir, any modz to your muffler, air-filter, or when you change your sparkplug to either splitfire, or multi-ground strap sparkplugs, will cause imbalances to your A/F mixture. usually it goes too lean that causes back fires.

look for another mechanic who can adjust your A/F mix properly. it looks like the mechanic of probikes doesn't know much about A/F mixtures. be careful, there are so-called mechanics who learned the trade by apprenticeship only, such in the case of several mechanics i know here in our city. i could see they don't really know theories and technicalities about bikes... just assembling them and replacement of parts.

no offense to all mechanics out there,... just a share about my experiences in our city. PEACE!

mga sir sabi sa akin ng mekaniko ng probikes minsan cause ng bike fire eh kung nagpalit ka ng muffler yung whole set po, tapos yung isa pa daw factor is singaw nga sa pipe like what sir g said, tapos finally is masyadong malaki ang opening ng muffler mo like what im experiencing sa z200 ko kasi yung muffler na nakakabit sa z200 is pang kotse. :)

sir magnus,

cnsya na, nakalimutan kong i-mention na i-check mo din pala yung color ng Spark Plug mo. kung maputi yung ceramic insulator sa electrode mo, definitely very lean na nga ang A/F mixture ng MC mo. you will need to adjust your A/F mix. The correct color according to our z200 user's manual is BROWN.

kung sakaling brown nga talaga yung kulay, have your exhaust system checked. baka dun lang ang problema ng Back Fires mo. i hope makatulong sainyo suggestions ko.

...

Mga Sir ask ko lang po meaning ng open carb, n encounter ko lang sa ibang thread.

Thanks

Hi guys!

May I also share my technique on adjusting our PZ27 carbs, which unfortunately I have just learned... only recently.

The technique is based on the Stoichiometric Ratio, which is 14.7:1 or 14.7 air is to 1 fuel (read this (http://en.wikipedia.org/wiki/Stoichiometric_air_ratio)). That is for every 14.7cc of air only 1cc of fuel is required to attain the highest combustibility of gasoline w/o being lean or rich. Meaning it is the finest tune for your Motorcycle engine EVER. Yup! It sounded as if you need to have a lot of measuring device to achieve this on your carb. In fact, it is the Stoichiometric Ratio that is being maintained in EFI or fuel injection systems where a lot of sensors is used to tell a computer how to attain the proper air-to-fuel ratio while running in different environmental conditions and loads.

Unfortunately with our carbs, we don't have a computer and sensors to accurately attain this fine A/F ratio. But with the technique that I have mentioned, we are blessed with the simple adjustment screws that we have on our PZ27 carbs: the idle-speed adjust screw and the mixture adjust screw to achieve Stoichiometric Ratio (Pls refer na lang from the z200 parts manual found on the XPhil website for the proper locations of this screws. Anyway, most of the forumers in this thread knows it already.) The mixture adjust screw is also called Air screw in other sites, and this is what we need to focus on. To attain the Stoichiometric ratio, you don't need to know which way with the mixture screw is going lean and which way is going rich. You don't even need to turn the mixture screw to full close, where it is risky for the mixture screw gasket and spring to get damaged. Just do the following:

1. START THE ENGINE AND LET IT WARM UP to operational temperature (you may ride it around your barangay or subdivision for a few minutes also). Do not adjust carburetor when engine is cold.
2. With the engine running at idle speed. turn mixture adjust screw slowly clockwise (turning in) by 1/4 increments, until engine falters. Stop at this point. Now turn screw counter-clockwise by 1/4 increments until the engine falters again. But this time, count the number of turns.
Note: The PZ27 mixture screw is quite small and facing downward, that a proper precision flat-head screw is needed. It should be short enough so you don't get burned by the hot engine.
3. Divide the number of turns by 2, and take note of the quotient.
4. Turn screw clockwise by 1/4 increments again, and count until you reach the quotient. This is exactly halfway between your first and second positions, and the optimum setting on your carburetor.
5. After mixture adjustments have been made, idle speed may need to be adjusted to its user's manual prescribed rpm for idling.
The main idea of this 5-step procedure is to find the Stoichometric ratio between the leanest and richest operating condition of the carburetor, without using any measuring device. It is based on the fact that, engines run poorly when too lean, and runs poorly when too rich. So the mid-way between this two points (lean and rich) must be the ideal A/F ratio.

But wait... this procedure only works if both your carburetor and engine don't have damages. It is best to have them fixed first before doing the tuning. Anyway, you can find out during the procedure if there's something wrong with your carb or engine. Visit this site: http://www.off-road.com/atv/kidskorner/idleadjust.html

FINAL WORD: Adjusting carbs on our own is really not advised by mechanics because of the dangers mentioned above, and they thought we can't get well informed enough to go around these dangers. Well, let's understand them. But when you have modifications on your exhaust pipe and airfilter, change to split-fire cable and plug, you will need to re-tune your carb. So it is nice that you know the proper how-to, instead of taking the trouble of going to the mechanic and pay for his services for the simple re-tune. I personally believe, that the procedures I mentioned here are quite safe for your carburetor and engine, as long as it is followed properly to the letter.

ASTIG.... nasolve nito ang gas consumption problem ko.. HINDI NA SYA MALAKAS SA GASOLINA.... umaabot na sya ng 40km/liter... WOW

tnx sir,,,