200x carb and jetting

[Jmoozy27]

What carb and jetting are you running on your 200x? 1st gen / 2nd gen - Auto X / Super X / Standard X = It doesn't matter. LET US KNOW:

My super X has a 1st gen carb w/ 125 main and 40 pilot. Just moved the needle to the bottom clip and still just a hair lean.

[yaegerb]

Lean on which circuit?

[Jmoozy27]

It seems to be low mid and high from reading the chop although you wouldn't know that from riding it. It grunts good with no popping. I don't think it is far off as the white of the plug has a slight tint when it did not yesterday. (Before I raised the clip). Just curious what everyone else's jetting was. What are you running Brennan?

[yaegerb]

I run a mikuni on the x. What mods are done to the motor?

[Jmoozy27]

1st oversized 10.5:1 wiseco, 86 200x exhaust with inner weld grinded and spark arrester uncorked but still intact. Modified air box w/ uni filter. 1st gen carb(which I got from you) connected to a custom intake made from an 86 200x but only about 1/2" longer to clear the electric starter.

[barnett468]

It seems to be low mid and high from reading the chop although you wouldn't know that from riding it. It grunts good with no popping. I don't think it is far off as the white of the plug has a slight tint when it did not yesterday. (Before I raised the clip). Just curious what everyone else's jetting was. What are you running Brennan?

you cant use quite the same standard for reading plugs these days because of whats in the fuel so if the porcelain is light brown and it runs perfect as you say it does, i would leave it . . the other option is to keep jetting it up until it starts to burble upon acceleration then go down a couple steps.

also, the hotter it gets outside, the richer it will become, therefore, unless you don't expect it to get any hotter than it currently is where you are located, i would leave it.

.

[Jmoozy27]

you cant use quite the same standard for reading plugs these days because of whats in the fuel so if the porcelain is light brown and it runs perfect as you say it does, i would leave it . . the other option is to keep jetting it up until it starts to burble upon acceleration then go down a couple steps.

also, the hotter it gets outside, the richer it will become, therefore, unless you don't expect it to get any hotter than it currently is where you are located, i would leave it.

.
Thanks, I run non ethanol 91 octane, I will keep going up on the main, it was right on before I modded the suspension so it's not far off. I'm really not asking for jetting advice as I just want to know what kind of carb and jetting other 200x owners were using. Thanks for the advice though. I ordered this carb to try on it just to see if there will be a performance gain. Any advice on it.

http://m.ebay.com/orderDetails?itemId=171726869666&txnId=1407364863007

[dmfaulks85]

Mines bored .20 over, wiseco 10:25:1, full dg exhaust, K&n air filter and I run a 110 main

[barnett468]

Thanks, I run non ethanol 91 octane, I will keep going up on the main, it was right on before I modded the suspension so it's not far off. I'm really not asking for jetting advice as I just want to know what kind of carb and jetting other 200x owners were using. Thanks for the advice though. I ordered this carb to try on it just to see if there will be a performance gain. Any advice on it.

http://m.ebay.com/orderDetails?itemId=171726869666&txnId=1407364863007

jmoozy, thanks for the info . . even the non ethanol gas leaves a little different appearance on the plug than the old leaded and unleaded gas does . . this is because most of it is called tier one which means it has a lot more cleaning agents etc in it . . if you have a newer car and look at the plug, it will be nearly white . . yes part of this is due to the efficiency of the engine with the fi and computers etc but it still gives an example of what i mean.

anyway, glad to hear it runs so well . . others are far less fortunate.

as far as the carb goes, the link you posted is incorrect, but in general, if you have some mods like a high perf pipe and cam and more compression etc, you will gain more mid and top end power with a carb that is slightly bigger than stock . . a safe increase in size before you might start loosing bottom end perf in most cases like this is 2 to 3 mm.
.

[Jmoozy27]

http://www.ebay.com/itm/171726869666?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Try this one, it is a 27mm keihin which I believe to be off of an xr200, I will keep using the carb I have now until I do more mods but I like the way it runs now. I have a 86 200x motor in pieces needing a rebuilt top end that im not sure what I will do with yet. I figured $25 was a good deal on what looks to be a good carb so I couldn't pass it up. It doesn't say, but I think it has an accelerator pump as well.

[yaegerb]

If you are on the last clip (bottom) of the needle, then you need a different taper needle (richer needle). I would drop to a 118 main, 125 is really rich for those mods. Leave the pilot at 40

[Jmoozy27]

I thought about doing that or putting a small washer to pick it up a little higher. I do have some extra needles put the are all significantly shorter or fatter.

[yaegerb]

A shim would work also. Jetsrus sells them

[Jmoozy27]

I got the carb in today. It's a pd29a keihin. I'm not sure what it is off of but it looks brand new.217328 217329 217330 217331

It has a second cable connection that operates the accelerator pump. Doe anyone know what cable I would need for this? Maybe a twist throttle???

[barnett468]

I got the carb in today. It's a pd29a keihin. I'm not sure what it is off of but it looks brand new.217328 217329 217330 217331

It has a second cable connection that operates the accelerator pump. Doe anyone know what cable I would need for this? Maybe a twist throttle???

Ok, nice, a pumper carb.

if the size of the bore on the exit side is 29 mm, and the bore is oval in the center of the carb where the slide is, it is not a 29 mm . . an approximate size would be 2 - 3 mm smaller than the bore depending on the bore size and i see yours does have 27 mm hand written on it so perhaps the person selling it knew what they were doing.

as far as the pump needing a separate cable, this sounds like a chinese carb to me and i dont know what you could use other than a throttle from a japanese made bike . . you can find these on two chinese sites, aliexpress.com and alibaba.com.

[Jmoozy27]

Well that sucks if it's a knock off... It's not like the ones that I have seen it the past. But I have seen some pretty impressive looking Folex watches in my time. What the hell.. It'll get used regardless. I'll pull the bowl off tonight and see if it has keihin jets.

[barnett468]

Well that sucks if it's a knock off... It's not like the ones that I have seen it the past. But I have seen some pretty impressive looking Folex watches in my time. What the hell.. It'll get used regardless. I'll pull the bowl off tonight and see if it has keihin jets.

well, if i recall correctly, damon told me that the chinese keihins were in fact real kehins made by kehin but they were the chinese models made in china for the chinese market . . the easiest way to tell if it is a chinese carb is by the price . . if it is brand new and is $50.00 or less, it is likely either stolen or it is a chinese carb . . in fact, i can buy these chinese made carbs they sell on ebay for $30.00, for around $14.00 direct from china.

also, if it has an ink stamp on it that starts with the letters PZ, it is a chinese made carb.

[Jmoozy27]

I have seen the pz models on eBay and have searched long and hard for this one. I'm hoping it's one of the discontinued DG keihins.

[ironchop]

I was told recently by an authorized dealer off the record that the Japanese big four have been using Chinese manufacturers to make a lot of their parts for many years now anyway. He said that was why Lifan and another brand were very reliable and well made. He did say some Chinese plants still make junk but that others were hi-tech and hi quality and capable of supplying the Big Four.

Anyone else heard this?

I've had unmarked Chinese carb and it was junk but I had another Chinese carb with a "K" cast into the slide housing and it was a good carb.

[yaegerb]

So....I am confused. Are you going to swap the OEM for that one? For your mods that OEM is more than sufficient other than getting a different needle. And I guess I am confused with that as well.....that needle should be sufficient (not lean) as well. Have you checked the intake for leaks?

[Jmoozy27]

No, I'm not planning on using it with this build at this time. I just have lots of ideas and a wealth of parts. It mostly just for experimental purposes at this point. We will see...

[Jmoozy27]

I was told recently by an authorized dealer off the record that the Japanese big four have been using Chinese manufacturers to make a lot of their parts for many years now anyway. He said that was why Lifan and another brand were very reliable and well made. He did say some Chinese plants still make junk but that others were hi-tech and hi quality and capable of supplying the Big Four.

Anyone else heard this?

I've had unmarked Chinese carb and it was junk but I had another Chinese carb with a "K" cast into the slide housing and it was a good carb.

Well that is good to hear!!!:)

[Toaster556]

That carb may be an OE Honda carb from a 1985 CB125S. They had the same goofy split throttle set up on a Keihin, as did the later model CG125 push rod bikes. Those throttle cables can be found on eBay from UK sellers. I've always wanted to try one, but dialing in the squirt on my buddy's WR250F was enough of a nightmare to scare me away from it.

I run a knockoff carb body, with Keihin guts (everything from cap to float bowl) on my 82 ATC200, and it works great! The knock off jets were even numbered, just a bit on the lean side.

[barnett468]

I'm hoping it's one of the discontinued DG keihins.

If you are referring to DG Performance, I have never seen them offer a 29 mm carb, but I suppose they could have and I just never saw it.

[Jmoozy27]

That carb may be an OE Honda carb from a 1985 CB125S. They had the same goofy split throttle set up on a Keihin, as did the later model CG125 push rod bikes. Those throttle cables can be found on eBay from UK sellers. I've always wanted to try one, but dialing in the squirt on my buddy's WR250F was enough of a nightmare to scare me away from it.

I run a knockoff carb body, with Keihin guts (everything from cap to float bowl) on my 82 ATC200, and it works great! The knock off jets were even numbered, just a bit on the lean side.

Thanks I will continue to research this. I hope that is the case.

[Jmoozy27]

If you are referring to DG Performance, I have never seen them offer a 29 mm carb, but I suppose they could have and I just never saw it.

Me either, I'm going off strictly speculation. I just feel like this carb is too well designed to be a cheap knock off. I will look at the inards when I get home.

[barnett468]

Me either, I'm going off strictly speculation. I just feel like this carb is too well designed to be a cheap knock off. I will look at the inards when I get home.

ok, I looked at this before after Damon told me that the Keihins from China are real Keihins made by Kehin, and in fact they are, but he already knew this because he was looking into this before and he also has a Chinese made engine in his trike he built . . I just wanted to see exactly what Kehin had, and where they had it.


http://www.keihin-corp.co.jp/english/company/hstory.html


http://www.keihin-corp.co.jp/english/company/china.html

nanjing Keihin Carburetor Co., Ltd.

Longchi streets Longhua Road, No.1 Luhe District, Nanjing, Jiangsu CHINA, TEL .+86-25-5715-2305

"Manufacture and sale of motorcycle and general-purpose products, and automobile products, and service center"

[Jmoozy27]

It has a 105 main & 38 pilot all keihin jets. Also a nice K stamped into the float bracket. I'm kind of leaning towards it being a stock carb that was taken off of a bike for whatever reason. The fuel inlet of the carb looks like it had a hose on it for a long time but never had fuel flow through it. I would like to know what machine it was designed for.

[Toaster556]

Those numbers match the CB125s jets. How big is the venturi at the flange? Slide diameter?

[Jmoozy27]

30mm on the engine side. I think 50mm on the other and it has the same size slide as the 200x carb.

[barnett468]

.

I got the carb in today. It has a second cable connection that operates the accelerator pump. Doe anyone know what cable I would need for this? Maybe a twist throttle???

Ok, I'm on a bigger screen now so I can see your carb better . . Unless I'm missing something, that takes a single cable throttle cable and the pump is actuated by the one black cam just like all the other ones I have seen.

Here's video of it in action.

http://s354.photobucket.com/user/loudfastugly/media/pd17throttleblip_zps91a62857.mp4.html

[barnett468]

.
Ok they also used that style carb several years of the non USA model of the CG125 . . If you do need a split cable, there are several in the ebay link below.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xcg+125+th rottle+cable.TRS0&_nkw=cg+125+throttle+cable&_sacat=0

1998 CG125 ORIGINAL HONDA CABLE PHOTO

http://images.cmsnl.com/img/products/cable-compthrot_medium17910KCH650-01_c507.jpg

[Jmoozy27]

I wonder if I could rig it up to a thumb throttle?

[Jmoozy27]

Some pics of the jets and stamped float

http://www.3wheelerworld.com/attachment.php?attachmentid=217352&stc=1 http://www.3wheelerworld.com/attachment.php?attachmentid=217353&stc=1 http://www.3wheelerworld.com/attachment.php?attachmentid=217354&stc=1

[Toaster556]

30mm on the engine side. I think 50mm on the other and it has the same size slide as the 200x carb.

I would lay money on it being a early 80s CB125S carb. See THIS THREAD (http://planetminis.com/forums/z50-ct70-jdm-monkeybikes/189473-feeding-108-keihin-pd-pumper-carb-thread.html)

[Jmoozy27]

I would lay money on it being a early 80s CB125S carb. See THIS THREAD (http://planetminis.com/forums/z50-ct70-jdm-monkeybikes/189473-feeding-108-keihin-pd-pumper-carb-thread.html)

It seems to be very similar, but mine has a 30mm opening, an adjustable needle, and the A/F screw is mounted on the side between the flange and slide. Was there any slightly larger bikes that could have used it like a 150 175 185?

[barnett468]

.
The carb in the link that Toaster posted is a NOS 1985 CB125S carb p/n 16100-441-972 . . this number was niot used on any other years.

the date the thread started was 5 - 2013 . . he did not say when he bought that carb and i have no idea how he found a brand new 30 year old carb.

[barnett468]

I wonder if I could rig it up to a thumb throttle?

as far as i remember, honda only used two different threads for their cables so you have a 50/50 chance of the thread size being correct, however since your cable comes out horizontal to the throttle, and the cg125 cable does not, it wouldn't work with your particular throttle anyway.

[Jmoozy27]

Went up to a 130 slotted main w/ a utility carb bowl without the thread fitting to quick change the main. Stock Needle on 2nd richest setting with a small washer to raise it slightly. 2.5 turns out on AF screw. I am much happier with chop color.
http://www.3wheelerworld.com/attachment.php?attachmentid=218057&stc=1

[yaegerb]

Yep that looks better. Any hesitations or popping under load?

[Jmoozy27]

Yep that looks better. Any hesitations or popping under load?

Not at all, smooth through all circuits...:w00t:

[yaegerb]

excellent.

[barnett468]

It looks slightly rich . . the old method of reading plugs has not applied for several years do to the corn licquor and/or the super clean burning tier one gas . . it should only have a light ring of black on the end of the threads and the porcelain will not look nearly as dark as it used to with the same jet size . . the plugs in my v10 Chrysler engine I just had smogged have 30,000 miles and look nearly pure white on the porcelain with 0 black on them . . of course its computer controlled up the whazoo but even plugs on old cars look lighter than they used to.

[Jmoozy27]

I'll take slightly rich over barely lean any day..;)

[barnett468]

I jet my bikes a hair on the rich side . . your jetting was far from dangerously lean before . . if it was dangerously lean it would have had a hesitation but you said it ran perfect . . the carbon that immediately covered the end of your threads will most likely cover the top of your piston and head and valves too but if you prefer that then you should leave it rich like it is.

[Jmoozy27]

I jet my bikes a hair on the rich side . . your jetting was far from dangerously lean before . . if it was dangerously lean it would have had a hesitation but you said it ran perfect . . the carbon that immediately covered the end of your threads will most likely cover the top of your piston and head and valves too but if you prefer that then you should leave it rich like it is.

I plan on leaving it the way it is because this is the jetting and plug color that I have been shooting for. If you think that it will cause some sort of damage to the motor to run it at this setting then I disagree with you. My comment about being dangerously lean was sarcastic and was noted by the green circle with the "Big Grin" but I can change that because fortunately I do have an edit button. Thanks for your opinions.

[barnett468]

I plan on leaving it the way it is because this is the jetting and plug color that I have been shooting for. If you think that it will cause some sort of damage to the motor to run it at this setting then I disagree with you. My comment about being dangerously lean was sarcastic and was noted by the green circle with the "Big Grin" but I can change that because fortunately I do have an edit button. Thanks for your opinions.I did not say or imply that it would cause damage to the engine . . i stated a probable effect of running it rich which is carbon build up just like there is on your plug threads . . your head and piston are not magically protected against this build up and in fact I guarantee you with 100% certainty that at the very least the area on your head around your plug has at least some carbon build up too and this build up will in fact continue to some unknown degree . . these are not opinions

[Jmoozy27]

So what were you insinuating initially? That if I did what you recemmended that it would magically reduce the amount of carbon in my engine... I much rather remove the head and inspect/clean any build up on occasion than run an engine lean and damage something expensive and rare. Wouldn't you?

[barnett468]

So what were you insinuating initially? That if I did what you recemmended that it would magically reduce the amount of carbon in my engine... I much rather remove the head and inspect/clean any build up on occasion than run an engine lean and damage something expensive and rare. Wouldn't you?
Yes, leaner jetting will in fact reduce fuel relatet carbon build up in an engine that is jetted too rich but t does not do it by magic, it does it by scientific processes . . the point again is that according to your spark plug condition and description of how it ran with the smaller jet, it was in no way shape or form anywhere near lean enough to cause any damage . . I have jetted well over 500 carbs and done well over 1000 jet changes and I do most all of them using the same method . . I have jetted some on the dyno and most of those were in need of rejecting once the vehicles were actually driven . . you can also use a wider band Afr meter as a guide to jetting and they can be found for under $100.00 on occasion . . in addition to a hesitation from being too lean another indicator can be detonation . . in some instances,if the jetting is too lean, an engine will begin to have detonation . . since not all detonation is audible, you can buy a detonation sensor and use this as a tuning tool by itself or in addition to the Afr meter for jetting and timing . . In regards to your last question, I jet my engines so they are neither so lean that they might sustain damage nor so rich that they sustain e_cessive carbon build up . . in fact, if an engine is jetted rich enough it will quickly cause ring damage.

[Jmoozy27]

Well, let's be simple here. I'm a good old boy. Not a scientist or an engineer. My numbers are decent too. I have handled about umm 53 carbs on all sorts of machines. And as far as jets I have probably changed about 127 give or take a few that weren't even worth the time. I like how it runs. I like how it looks. It will stay like that until the machine shows me otherwise. I'm not saying your info isn't helpful, it's just not helpful to me on this particular subject. Thanks again Barnett. My next build will be somewhat of a racer and I will listen to your tech knowledge better then.