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Discussion Starter #1
OK boys and girls... I have a twisted feeling in my gut... part excitement, part fear...

I think it was less than a week ago I made a comment along the lines of "I'm a carb guy but I would never rip EFI out of a bike"

I just ordered a Zongshen 190cc motor to wedge into my Z:

https://pitsterpro.com/index.php?route=product/product&product_id=79

It is branded GPX but it is the same as the Zong. Zong also makes the Japanese Daytona motors that are very popular for pitbike racing (4 valve vs 2 valve head is the difference).

If you use coupon code "zs190" you will get the motor shipped to your door for $640.

Motor comes with all electrical accessories to get it running, a carb, and oil cooler (I confirmed this by calling them, other kits list it but this one does not specifically).

This would be a direct plug and play in a Tao Tao Hellcat 125 (grom clone) so the plan is to pick up a Hellcat wiring harness. Will most likely get Hellcat coil/rectifier/CDI/ignition etc as well... the parts are cheap!

Will need to fabricate or buy brackets to convert Z mounting location to what seems to be industry standard Honda (except for grom) mounting points... seems like a lot of these motors all share the same mounting points.

Pretty much all Z wiring goes away.

Speedometer will need to be aftermarket because Z speedo is tied to engine RPM. Will need one tied to wheel rotation. Not sure about cluster yet.

The motor is a 5 speed with electric and kick start.

You can run 428 or 420 sprockets, chain length TBD.

Power wheelies in 2nd?

>:)

Here we go...……..
 

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Discussion Starter #3
Going on a trip with the Z so it will need to wait a while before I rip into it... going to collect parts in the mean time.

The motor puts out like 22-24 hp!
 

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I'd imagine it can't be that hard to get the OEM cluster working with the ZS190 motor. The cluster has all relays and whatnot to make the indicators work correctly(ish). I thought someone on Facebook spliced into the OEM harness and used the stock ECU to essentially drive the indicator. I'm not sure how the ZS190 and Z125 tach signals differ, but translating between the two shouldn't be too hard...
 

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The motor puts out like 22-24 hp!
Holy hellfire that will be fun. Once you've got it up and running I give your girlfriend one ride on it before she asks for the same treatment on the Grom. XD

If you use coupon code "zs190" you will get the motor shipped to your door for $640.
That's crazy cheap... Ignoring cost of install that's roughly the same cost as a Bazzaz + auto tune. But instead of an optimistic 15% power gain you net a 300% gain? That's some good maths you have done my friend!

I guess it pays to be old school (and handy). :grin2:
 

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my '87 xr250r puts out about 24hp, that would be awesome power for a Z
 

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Subscribed!

I'm rebuilding my Z right now cause I blew it up out on track. Steady Garage has a mounting kit for this on their website. I'm really wanting to do the 212cc conversation cause I already have the 194cc TB kit. (NEED MORE POWER!)

It looks like the stock z intake and throttle body will mount right up to this thing? Doesnt it? For the engine wiring, is it just a kill switch/starter that needs to be wired up? What else needs to?

Thanks for updating and being a Guinea pig for the rest of us ☺
 

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Going on a trip with the Z so it will need to wait a while before I rip into it... going to collect parts in the mean time.

The motor puts out like 22-24 hp!
Not to burst your bubble but the 4V Daytona makes that kind of power, not the 2V ZS190. Reliable dyno figures put it closer to 17HP at the wheel. Take a look in the cylinder head ports to see why. It's a bit disappointing. The head can be ported to increase airflow but there's a reason they are selling them so cheap. Ask me how I know... Oh and it's VERY heavy compared to stock. And then there's the Chinese engine reliability aspect.

If you already have one on order then you will need motor mount brackets like these: https://www.steadygarage.com/store/chimera-bracket-mount-zs190-engine-kawasaki-z125-pro

I am willing to sell my new mount kit and the new engine if anyone wants to make an offer. I never ran it, just bought it, inspected it and THEN did my research. It looked pretty good at first and it's a cheaper alternative to replacing a damaged Kawi engine but it's not a high performance engine, just bigger. It's not what I hoped it would be, so I'm selling it. Probably a great swap into one of those Chinese bikes and a lot easier than fitting it into the Z125. Good luck.
 

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Discussion Starter #10
I thought someone on Facebook spliced into the OEM harness and used the stock ECU to essentially drive the indicator.
Yeah... the guy's name is Gus and he has what I believe to be the first documented 190 swap into a Z. Nice guy. I spoke with him a bit yesterday. I hope to see farther by standing on the shoulders of giants... that being said electrically his bike is a mess.

He is running the wire harness that comes with the motor for kill switch, coil, rectifier, CDI... maybe some other stuff I am forgetting... pretty much all the motor related electronics.

He has stock wire harness for signals and other lights.

Problem is he can't get the ZS190 to charge his battery. The quantity of wires between Z components and ZS components is mismatched and they can't talk to each other. So his lights are running off battery which doesn't get recharged when riding, and he has no tach or speedo. Check engine light on all the time for multiple errors.

When the parts get here I'm going to either:
1. Use ZS harness and new wiring for all lights
2. Get Grom clone harness for more plug and play (wire length for signals and headlight etc will probably be close), but my understanding is the engine electronics will need to be swapped to grom clone electronics so # of wires match up.

Really need to get it in hand to see what I am dealing with.

My build plan is to have everything connected on the bench, and fire the motor on the bench to make sure everything is connected correctly, then figure out how to jam everything into the Z.
 

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Discussion Starter #11
It looks like the stock z intake and throttle body will mount right up to this thing? Doesnt it? For the engine wiring, is it just a kill switch/starter that needs to be wired up? What else needs to?
Intake and throttle body may bolt up, I can check when I start to tear down. I have not really considered fuel injection due to added expense, but I there are a couple guys on the ZS190 Swap Shop facebook page who have done it to Grom clones. Seems like you need a stand alone ECU to do it. I imagine a larger injector. Those guys used stock fuel pump.

As for wiring... you need to connect kill switch, ignition switch, coil, rectifier, and CDI. The connections (# of wires) on the parts that come with the ZS190 and the Z are different. Everyone seems to think you need to go with a clone wire harness and it becomes more plug and play. But that means stripping all wiring from the Z, which I think is a forgone conclusion for this swap. My preference is to make the harness that comes with the motor work, get the battery charging, and then worry about wiring up lights and signals on my own. Maybe something like this:

https://www.revzilla.com/motorcycle/motogadget-m-unit-basic-digital-control-and-fuse-box?gclid=CjwKCAjwqqrmBRAAEiwAdpDXtJIZdBbD4Ct2-SLHP3eZkKCLkf3Q8B1uAEaxJ-3v_vkRK4N-E4JIxhoCPD4QAvD_BwE

This thing is rad it is a fuse-less fuse box, all electronic, built in signal flasher relays, built in brake flasher, you can run one control wire to handlebar to pick up everything there (add on) and you can do keyless (like swiping your card near a hotel door) for startup. Kind of pricey at 300 bucks but I've been wanting to play with one for a while.

With a device like this getting lights and accessories up and running without the stock wire harness would be a piece of cake.
 

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Discussion Starter #12
Not to burst your bubble but the 4V Daytona makes that kind of power, not the 2V ZS190. Reliable dyno figures put it closer to 17HP at the wheel. Take a look in the cylinder head ports to see why. It's a bit disappointing. The head can be ported to increase airflow but there's a reason they are selling them so cheap. Ask me how I know... Oh and it's VERY heavy compared to stock. And then there's the Chinese engine reliability aspect.

If you already have one on order then you will need motor mount brackets like these: https://www.steadygarage.com/store/chimera-bracket-mount-zs190-engine-kawasaki-z125-pro

I am willing to sell my new mount kit and the new engine if anyone wants to make an offer. I never ran it, just bought it, inspected it and THEN did my research. It looked pretty good at first and it's a cheaper alternative to replacing a damaged Kawi engine but it's not a high performance engine, just bigger. It's not what I hoped it would be, so I'm selling it. Probably a great swap into one of those Chinese bikes and a lot easier than fitting it into the Z125. Good luck.
Lobot - you bring up some good points here.

First on power:
Yes, you are completely correct, I overstated power. SteadyGarage lists HP for the 2 valve ZS at 18hp... still a real nice bump. From everything I've read on this, and from hearing from people on the minibike forums, the only difference between the Daytona and the ZS is the head (2v vs 4v). Pretty incredible that the head can boost HP by 28%. The good news is that those 4v heads bolt on to the ZS. If you were so inclined you could add the 4v head to your ZS. I found this pricing this morning:

Daytona OEM 4V Head - $350
Daytona OEM 212cc Big Bore Kit (can use with either head) Piston, Rings, Cylinder - $300

As alternate to big bore kit, you can by piston and rings for about $75 and get your cylinder machined, may save money.

So you can boost the power back up to Daytona range and still save a few hundred bucks with the ZS.


Weight:
Yeah heavier than stock, but more than double the power. Go on a diet? There is no replacement for displacement (it is just bigger).


Chinese Quality:
This was my biggest concern. I got over it by considering the following:

1. All these motors are clones of the Honda CRF design. It is not like it is an untested design.
2. Zongshen is one of the largest motor manufacturers in China. They make tons of bikes and ATVs and have been around for almost 25 years.
3. Zongshen makes the Daytona, in the same factory. Parts are interchangeable. I really believe it is the same motor minus the head.
4. Making these simple air cooled motors is not really that complex. I would wager that with the startup funds, a lot of guys on this site could setup a CNC machine in their garage and make these. This is really old tech and there is no doubt that a large Chinese company would not be able to make these parts to correct tolerances.
5. If it breaks, it breaks, and I will fix it. OEM parts are dirt cheap for these things.
6. Reputation in pit bike circles. The guys in the forums say they run the crap out of these motors and they take a beating. Rev up to 15k. I would not work mine nearly that hard. Would gladly sacrifice some power for reliability. My gut is these would be more reliable than a big bore kit with paper thin cylinder walls. But that is just conjecture.
7. There are lots of videos on youtube with guys running these in Grom clones and they are having a blast. You are totally correct swapping into a grom clone is the easiest way... but after riding both bikes extensively I really like the feel and handling of the Z better.

Plus I spent big bucks on my Corbin seat so now I NEED to keep the Z :)

At the end of the day for $640 delivered I couldn't say no. Daytona 190 is like $1200 without all the accessories.

Will keep all stock components in tact in case I want to switch back.

Always appreciate a contrarian viewpoint it keeps people honest.
 

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Psssh, look at all that research, and we thought you bought it on impulse! =P
 

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Discussion Starter #14
Honestly it kinda was spur of the moment and Lobot brought up legit concerns... I managed to delay myself about 18 hours while I looked into it and figured for the price I'll roll the dice.

I would be happy to get 10k miles out of the motor before it starts to go.

At the end of the day, this project will be successful if and only if I can lift the front wheel using only my right wrist.

Motor arrives Wednesday.
 

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Lobot - you bring up some good points here.

First on power:
Yes, you are completely correct, I overstated power. SteadyGarage lists HP for the 2 valve ZS at 18hp... still a real nice bump. From everything I've read on this, and from hearing from people on the minibike forums, the only difference between the Daytona and the ZS is the head (2v vs 4v). Pretty incredible that the head can boost HP by 28%. The good news is that those 4v heads bolt on to the ZS. If you were so inclined you could add the 4v head to your ZS. I found this pricing this morning:

Daytona OEM 4V Head - $350
Daytona OEM 212cc Big Bore Kit (can use with either head) Piston, Rings, Cylinder - $300

As alternate to big bore kit, you can by piston and rings for about $75 and get your cylinder machined, may save money.

So you can boost the power back up to Daytona range and still save a few hundred bucks with the ZS.


Weight:
Yeah heavier than stock, but more than double the power. Go on a diet? There is no replacement for displacement (it is just bigger).


Chinese Quality:
This was my biggest concern. I got over it by considering the following:

1. All these motors are clones of the Honda CRF design. It is not like it is an untested design.
2. Zongshen is one of the largest motor manufacturers in China. They make tons of bikes and ATVs and have been around for almost 25 years.
3. Zongshen makes the Daytona, in the same factory. Parts are interchangeable. I really believe it is the same motor minus the head.
4. Making these simple air cooled motors is not really that complex. I would wager that with the startup funds, a lot of guys on this site could setup a CNC machine in their garage and make these. This is really old tech and there is no doubt that a large Chinese company would not be able to make these parts to correct tolerances.
5. If it breaks, it breaks, and I will fix it. OEM parts are dirt cheap for these things.
6. Reputation in pit bike circles. The guys in the forums say they run the crap out of these motors and they take a beating. Rev up to 15k. I would not work mine nearly that hard. Would gladly sacrifice some power for reliability. My gut is these would be more reliable than a big bore kit with paper thin cylinder walls. But that is just conjecture.
7. There are lots of videos on youtube with guys running these in Grom clones and they are having a blast. You are totally correct swapping into a grom clone is the easiest way... but after riding both bikes extensively I really like the feel and handling of the Z better.

Plus I spent big bucks on my Corbin seat so now I NEED to keep the Z :)

At the end of the day for $640 delivered I couldn't say no. Daytona 190 is like $1200 without all the accessories.

Will keep all stock components in tact in case I want to switch back.

Always appreciate a contrarian viewpoint it keeps people honest.
I am glad you have done your research and know what you are getting into. I think the "bang for your buck" with this swap is amazing since you are basically doubling your power for much cheaper than you can using the stock engine. But it's the little details that will take some time to sort out. Wiring, exhaust fabrication and general fitment issues will take patience & diligence. But there is also some satisfaction in building this beast yourself. I can't wait to see it run. Good luck!
 

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At the end of the day, this project will be successful if and only if I can lift the front wheel using only my right wrist.
On my 194cc motor, I can easily power wheelie with it geared for a ton of top speed. (15T, 28T) can get it barely in second if I pull up.
The only reason I'm considering the 212cc kit is that it would be more reliable than what I have now. I seized my motor on track. Luckily it's an fast-ish fix. Going back to stock crank for now.
 

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At the end of the day, this project will be successful if and only if I can lift the front wheel using only my right wrist.
On my 194cc motor, I can easily power wheelie with it geared for a ton of top speed. (15T, 28T) can get it barely in second if I pull up.
The only reason I'm considering the 212cc kit is that it would be more reliable than what I have now. I seized my motor on track. Luckily it's an fast-ish fix. Going back to stock crank for now.
you have a dyno graph of the motor. Would love to see the curve.
 

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On my 194cc motor, I can easily power wheelie with it geared for a ton of top speed. (15T, 28T) can get it barely in second if I pull up.
The only reason I'm considering the 212cc kit is that it would be more reliable than what I have now. I seized my motor on track. Luckily it's an fast-ish fix. Going back to stock crank for now.
Do you have an oil cooler on that motor? That big of an engine is making some serious heat along with all that power and those cooling fins on the cylinder just can't do the job on their own. Plus the 67mm cylinders are very thin especially near the cylinder studs, where they often warp. I'd recommend keeping the stroker crank and replacing the damaged 67mm cylinder with a 64mm cyl. Less likely to seize again. And it will still have plenty of tire lofting torque...

Not sure why you think a 212cc Chinese motor can be considered "more reliable" than a 194cc Kawi motor. More fun, yes. Cheaper to fix, yes. But more reliable in a track bike?

Let us know how that works out...
 

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you have a dyno graph of the motor. Would love to see the curve.
Yup. Here its is. This was just after first oil change on the fresh 194 build on 91. Tuned it for 100 octane a few weeks later, but dont have pics of the graph. The second on the other graph is stock with an Ebay SC Project and PCV and only 100% throttle tuning.
 

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you have a dyno graph of the motor. Would love to see the curve.
Yup. Here its is. This was just after first oil change on the fresh 194 build on 91. Tuned it for 100 octane a few weeks later, but dont have pics of the graph. The second on the other graph is stock with an Ebay SC Project and PCV and only 100% throttle tuning.
nice! I bet that thing hauls!
 
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