Yamaha 225 clone enginr

[bucklove]

https://goo.gl/photos/KJpmq381vfCr6QfZ8

[bucklove]

https://goo.gl/photos/qbwGeM5hEaUfhxF47

[bucklove]

https://goo.gl/photos/YhuAWvyiN1qBMoF26

[bucklove]

https://goo.gl/photos/RxJn7DpDc1bVHHPVA

[humanbeing]

The jet can find via http://jetsrus.com
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For whom addicted to TB http://chinariders.net/showthread.php?t=14466
These shop http://shop35091180.taobao.com | http://shop36761007.taobao.com (located in the carb "hub" -- Fuding) stocks carb parts in most China bike.

[SpudRider]

I'm now sure you have a Teikei MV30 carburator, which is a constant velocity (CV) carburetor. If you wish to change jets on your TK MV30 carburetor, you have several choices. Teikei carburetor main jets are sold by Yamaha, but they are fairly expensive.

http://www.motorcyclecarbs.com/Teike...n_Jet_C825.cfm

Many owners of Teikei carbs prefer to use Mikuni series N102/221, small, round main jets. The thread on these Mikuni jets is a little different from the Teikei jets, but they still fit pretty well. The Mikuni jets are more widely available than the Teikei jets, and are much less expensive. The current price for N102/221, Mikuni, main jets from Rocky Mountain ATV is $3.49 per jet. I personally use the Mikuni N102/221 main jets, and I like them.

https://www.rockymountainatvmc.com/p...mikuni%20jeets

You can read more about Teikei jets at the following thread.

http://www.chinariders.net/showthread.php?t=6501

[SpudRider]

As usual, Humanbeing has provided excellent links for several vendors of Teikei jets. Thanks for your help, Humanbeing.

[bucklove]

Thanks Guys that's awesome information!!!! 102/221 so that's the sizes the would give me in a "performance" kit for $50/$60 dollar???and that's all I need to upgrade my carburetor performance??? If so that's also cheaper then I was prepared to spend!!!! Now what do you guys think I should do about ordering parts for the motor, like the clutch for example??? And lastly how would I go about changing the sprockets for more power/torque??? Thanks again guys!!!!


Just curious.. what does MV stand for????

[SpudRider]

Originally Posted by bucklove

Thanks Guys that's awesome information!!!! 102/221 so that's the sizes the would give me in a "performance" kit for $50/$60 dollar???and that's all I need to upgrade my carburetor performance??? If so that's also cheaper then I was prepared to spend!!!! Now what do you guys think I should do about ordering parts for the motor, like the clutch for example??? And lastly how would I go about changing the sprockets for more power/torque??? Thanks again guys!!!!


Just curious.. what does MV stand for????

No, N102/221 is the Mikuni part number for the main jets. You can order the individual jets for $3.49 apiece at the link I provided. You can learn more about jet selection by reading the thread at the link I provided.

I suspect parts for the Yamaha XT225, or Yamaha TT-R225 engines will fit your Jianshi engine. However, I have not verified this suspicion, and I cannot guarantee it.

I also suspect the counter shaft (C/S) sprocket for the engine is a Yamaha sprocket. Measure your current sprocket, and compare it to the dimensions shown below.

http://www.jtsprockets.com/catalogue/model/6684



You need to examine the measurements for the rear sprocket. Since this sprocket is independent from the engine, it could be a sprocket from any manufacturer.

[bucklove]

Thanks again SpudRider!! My chain and sprockets are 525!! I just bought a chain last month....my friend told me to change the rear sprocket but I saw a YouTube video where if you went bigger in the front it would go faster...but I'm looking for power/torque..I'll get back to Google!! Another question I've really been thinking about is would it be OK to put a fmf exhaust slip on from a YZF450 on my 225 motor?? My jets are 96/34 and my Florida states elevation is 345 feet what jets would I go with??? I'm reading the other thread n I'm not sure...

[SpudRider]

The Yamaha XT225 employs a size 428, drive chain. Therefore, your Jianshe quad does not use Yamaha XT225 sprockets.

If you want to increase torque, you can either decrease the size of the front sprocket, and/or increase the size of the rear sprocket. If you change the sprocket ratio a lot, you might need to change the length of your drive chain. Therefore, I suggest you experiment with a C/S sprocket which is one tooth smaller for the engine.

I suggest you consider installing an FMF Universal Spark Arrestor, as detailed in the following thread.

http://www.chinariders.net/showthread.php?t=5974

[bucklove]

Thanks SpudRider!!! Your bike looks Awesome!!! I love the colors!!! About those jets.... I have 96/34 so what sizes would I want to use for a 'performance' upgrade??? I've read in the threads you directed me to that you guys like 132??? I don't know anything about jets... is that a big jump for mine??? I included a picture of my jets showing their numbers (which I'm sure you already saw) I saw the main jet you linked me to, is that one the performance upgrade for mine??? I just want to be positively sure before I order!!!! So if you could help my dumb butt out n tell me again what numbers to order and do I order both the big on and the little one and is their anything else I need to order along with it??? I'd like to get it right the first time around!!! I've read about guys going in again n again to get the right jet n making adjustments and I don't look forward to doing that task!!! I'm not bad with adjusting carbs, I owned a Landscape company for around 20 years and was constantly cleaning and adjusting 6 crews worth of two stroke engines, but I don't know anything about changing the "numbers " on those jets!!!! I also noticed you said the Mikuni threads are a little different than the TK threads, am I damaging the threads by using the Mikuni jets??? My elevation here in Florida is 345 feet according to Google... what does that have to do with anything for me or do I not even need to concern myself with it, I've read that you guys with the crazy elevations like 9000!!!, have to keep that in mind when changing jets... Again thanks so very much for taking your time out of your day to help me out!!!! Matt

[bucklove]

I found this on MCM posted in 2008 along my travels...could you translate it into laymans terms for me???!!!! This is exactly how my carb is performing, bogging at 3/4!!! I figured cleaning it would solve the problem but now I see not!!! It was pretty darn clean anyway!!! But I'd still like to put in some performance parts in it!!! What do you suggest??? And what's this about drilling out the EPA thing...I've heard about that many times in the past and this one "performance " jet kit company includes a drill bit for that purpose I guess...it includes alot of parts, I like the sales pitch this company gives but I'm sure with the "knowledge " I could just put the kit together myself and save around $50!!!! (6sigmajetkits.com)(And the fact that they had kits for numerous Chinese maunfacturers, and the say "we don't send you a couple different jets for you to figure out yourself, we send you the right one...so they make it sound like they take the guess work out of beefing up your carb!!!! Now if they'd only respond to my Email I sent yesterday!!! I'll probably find out the "secret to this kit before they get back to me...with your help!!!! Lol) I had a guy at DYNOJETS. tell me over the phone that he couldn't give me a jet kit because he didn't ever hear of JIANSHE-YAMAHA...even after I explained to him the motor n carb!!!!! That blew me away n the sales guy on the phone put me through to their "tech" department to figure this quandary out!!!! Lol!!! I couldn't believe that guy was even employed there as "tech" support!!!! There are lots of tuning and modification articles dealing with the normal slide carburettor, but few telling it like it is with CV carbs.
Some time ago I found this write up in a newsgroup that explains things very clearly. It certainly opened my eyes when dealing with these instruments.

At the end I include a sectioned view of a CV carb showing the all-important transfer or transition ports.

Here goes:

Here is the secret of the CV carburetor: up to 3/4 throttle, the engine
is getting most of its mixture from the pilot jets, not the jet
needle/needle jet combined orifice.

Compared to the pilot jets in an older slide valve carburetor, the CV
carb has a huge orifice. Whereas a slide valve carb might have a #17
pilot jet ( the hole is 0.17 mm in diameter ), a CV carb might have a
#30 to #45 pilot jet.

We all learned to calculate the area of a circle in junior high school.
The #45 pilot jet has SEVEN times the area as the #17 pilot jet.

So the CV carb's pilot jet flows most of the fuel into the carb when
the throttle isn't wide open and the slide isn't lifted far enough to
pull the jet needle out of the needle jet.

You can really enhance your off idle throttle response and improve the
midrange power by finding the pilot mixture screw and tweaking it about
half to one full turn counterclockwise.

The pilot mixture screw is probably hidden under a blind plug, forward
of the diaphragm cap on top of the carb, or underneath the carb,
forward of the float bowl.

If you cannot see a slot screw on the side or top of the carb or underneath it,
the EPA plugs are still intact. You have to pilot drill the plug, screw a
small sheetmetal screw into the pilot hole and then pull the screw and
plug out with a pair of pliers.

Now you can adjust the pilot mixture screw by turning it counterclockwise a bit.
Note that CV carb idle mixture screws work the opposite way. Clockwise is leaner,counterclockwise is richer.

Riders get into trouble when they expect the idle RPM to increase the
more they turn the screw counterclockwise. When they've gone too far,
the exhaust sound is dull and thudding and maybe the the idle RPM is
too low.

So they adjust the master idle knob to increase the idle RPM. Then,
when they twist the throttle grip open and closed, the engine RPM hangs
up at 5000 RPM and they wonder what the heck is going on?

The amateur tuner doesn't know about the three transition ports right
by the throttle butterfly's bottom edge. The transition ports are
getting fuel from the pilot jet too, but they aren't controlled by the
pilot mixture screw, they are controlled by the bottom edge of the
butterfly.

The amateur tuner tweaks the pilot screws CW and CCW and can't figure
out which way they should be turned because he doesn't understand that
the transition ports are getting fuel that BYPASSES the pilot screws...

Pilot fuel is sucked out of the float bowl through the idle jet. It
goes through a branched passage to a pattern of transition ports that
are covered by the edge of the throttle butterfly when it's closed. Air
from the fixed air jet is added to the same passage. Fuel/air mixing
occurs in the passage. As the throttle butterfly is opened *slightly*
the vacuum in the carb's bore can suck fuel/air mixture out of the
transition ports and the engine speed can increase smoothly. There is
another branch of the same passage that has an outlet about 1 inch
downstream of the transtion ports. Vacuum is weaker there. The pilot
screw adjusts fuel/air flowing out of that port...

When the idle RPM hangs up at 4000, 5000,even 6000 RPM, that tells the
experienced tuner that the pilot mixture screw is open too far. So, he
has to turn it back the other way to get the engine to idle smoothly at
the smallest amount of throttle opening and the least number of turns
out of the pilot screw.

You can do so much with pilot jets and adjusting the pilot mixture
screw, The strategy for adjusting the pilot mixture on a CV carb is to get the
engine to run smoothly at the specified RPM with the smallest amount of
throttle opening possible. The amateur tuner fools around with the
pilot mixture screws, not understanding that the engine is drawing fuel
air mixture from the transition ports that may be slightly uncovered by
the throttle butterfly, according to the setting of the master idle
knob and the synchronizing screws...

Now, one of the tests for pilot mixture setting is that you open the
throttle quickly, and close it. The engine speed should increase, but
it should return to the original setting. If it hangs up, the pilot
mixture is too rich, because the engine is ALSO getting fuel from the
pilot outlet port AND the transition ports.

> What about main jet size?

Let me educate you on the Mikuni/Keihin jet sizing system. It's just
like the pilot jet sizing system.

The orifice size is based upon a #100 mainjet having a hole that's
exactly 1.000 millimeters in diameter.

The area of this orifice increases as to pi times the square of the
radius, so you can see that going from a #100 main jet to a #120 main
jet will result in an orifice with an area that's 44% larger and will
flow far too much fuel whenever the engine has enough vacuum to suck
fuel out of the float bowls.

The engine will be drowned by excess fuel if you go up too many jet
sizes at once.

Going from a #100 mainjet to a #110 mainjet is not just one size jump,
it's FOUR sizes larger, #102, #105, #107, then #110.

Even the #110 mainjet has 21% more area than the #100 main jet. What
would make an intelligent rider think that his new exhaust pipe by
itself was going to raise his horsepower by 21%, requiring 21% more
fuel?

Constant vacuum carburetors rarely run on the main jet. You could even
probably get away with running the stock main jet or one that's just
maybe two sizes larger than the original jets.


> Will a needle shim be enough?. Should definitely be in the right direction.


Nope. That's an urban myth amongst amateur tuners that don't undertand
how CV carbs work. CV carbs have short fat needle without much taper,
and whacking open the throttle just doesn't lift the needle out of the
hole enough to matter. The grooves on jet needles with clips help
control when the tapered part of the needle begins to have effect, but
you'll get more off-idle acceleration effect out of turning the pilot
mixture screw just exactly the right amount.

You run at full throttle so rarely on the street or the highway, it
just doesn't make sense to mess around with main jets and needle
shimming. It makes a lot more sense to learn about the pilot jets and
how to set them correctly.

You may ask, "But why do all the tuning manuals say to start tuning by
finding the correct sized main jet?"

It's not about ultimate power, as shown on a dynamometer. You
can get a higher horsepower reading out of an engine that's just warm
enough to carburate cleanly than you'll get out of a hot engine.

Heat builds up during a long race and it builds up faster on a high
speed course like Daytona.

Racers who really *race* need a main jet that's big enough to pass
extra fuel so the engine won't overheat. The racers are willing to
waste fuel to keep the engine cool.

But the typical rider who buys a Dynojet or other kit thinks that he's buying "instant power"
and an instant solution to the EPA mandated lean burn jetting from the factory.

Sorry, it doesn't work that way. The rider who succeeds in getting what
he wants out of his engine is the rider who understands the technology
of that engine and why that particular technology was chosen for it.

[bucklove]

http://www.6sigmajetkit.com/?gclid=C...BH9xoCn1Tw_wcB

[Weldangrind]

Zongshen made a motor with the same frame of architecture, but it was either a 200 or a 230. I don't think they produce the engine anymore, but several parts are still available.