Odd build
 

So I have been riding my "hybrid" dirt bike for quite a few years. It's a 1993 CR125 chassis that has sported a reliable old Xr200 motor for many, many years... the registration stickers (mostly Idaho) are 1/4" thick and go back to the early 2000's maybe more.

The old XR finally gave up the ghost a few months ago. Blew a head gasket and wiped out the piston; still ran enough to get us home, albeit slowly. I wanted a "magic" button as I'm getting too old to kick flooded bikes on peaks over 8-9000' anymore.

Initially I was going to transplant a Crf230 motor, but dang if they aren't expensive little buggers!! $$$$ After looking for a good low cost motor and not finding one I decided to try a Zongshen 169FMM instead.

My research seems to indicate that these are pretty reliable motors, but my riding buddies are really REALLY not happy with my choice. May the Zong prove them wrong!! :hi:

#1 reason i want to keep my old hybrid CR125/230 is that I have spent a ton of time and money dialing in the suspension over the last few years. Custom springs for my weight, rebuilt rear shock, lightweight oil in forks, etc. It rides just the way I want it for single track and some whooped out open desert sections.

The motor is partway bolted in and I actually twisted the wiring up and fired her up for the first time about an hour ago!! Sounds really good.

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She's ugly, but I love her. :crazy:

Here's a shot of the new motor almost bolted in. The two back mounts are on, but the top mount is a little different from the 200 so i will have to make a new one.

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I pulled the cover off to try and figure out the wiring. Does anyone know the rated output of this style stator?
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For the record:
Black/red stripe goes to Honda Black/red stripe (To CDI)
Blue/white stripe goes to Honda Blue/yellow stripe (To CDI)
Green/white stripe to Honda Green (Ground)
Yellow and Peach go to regulator, which is aftermarket 4 wire. Will not work with the little Crf230 regulator.

Attachment 7655

The 6 wire plug going into the shifter for gear indication is useless to me so I just pulled it out.

169fmm
 

I've searched for hours on "169FMM" but there just isn't much good information out there. Most of what was found came from this forum. Big thanks to those who have posted!!

Here is my motor serial for anyone curious:

Attachment 7641

Odd build, odd guy, odd Introduction; I know...I know!
 

One issue that I do have is the sprocket alignment. Using a laser level to sight down the hub and sprocket it was pretty plain to see that the Zong motor's offset was about 8mm too far inboard. A new retaining method will be necessary. Any ideas?


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Any chance you could move the engine over to line up the sprockets ?

Not too easily. The clearance from the carb to the frame is already tight, so it would make that a new issue.
:doh:

2 holes CB/ 88mm https://translate.google.com/transla...F67&edit-text=

start the motor... put in gear get the shaft turning...
hold a angle grinder with a cutting disc on the shaft
& put a new groove in it.....

LOL... well yer did ask...




...

Welcome to here! Usually, the friends are trying to keep one away from an entire bike, not the engine. I have little doubt the engine WILL prove your friends wrong.

Thank you!

So 90W is all. Ok. For future searchers:

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Hmmm... :D

The backlash against this motor has been epic. My intent with this forum post is to document the issues that may or may not come up such as the sprocket alignment. If this motor ever leaves me stranded it will be a chorus of "We told ya' so!!".

Interesting pictures
 

So this 69mm piston and cylinder kit was one that humanbeing linked to on Taobao. Learned alot about buying from there. Thanks HB!

You guys might actually find these interesting. The new cylinder is the 250cc cylinder kit, the old is my 200. I'd like to get a hold of a 230 to do some side by side comparisons.

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Welcome!


You've hit some hot buttons for me. I had an '88 CR125 that I was going to do the same thing with, but a buddy of mine needed it more, so I gave it to him. He bought a Gio dirt bike with a CG230, and we intend to transplant it into his CR. He's around 6'3", so the CR will suit him much better than the Gio (which is a small wheel bike).


Did you have to get creative with lower motor mounts, or could you use the CR mounts on the XR engine? I spotted that you'll need to do something custom on the upper mount. I'll be watching for your solution, and then I'll promptly steal it. :D


Fundamentally, your new cylinder isn't actually a 250 kit, in the same way an SR250 Yamaha is actually around 230. There isn't a 250 combo for a CG motor that I'm aware of, unless you want to go liquid cooled. The three-wheeled trucks from China often use that setup, which gets near 270cc, IIRC.


Is the wristpin diameter the same on your new cylinder as on the XR200? Is it the same as your China motor?

The 200 that was in it was done years ago by a previous owner. The rear lower and mid mounts bolted right up!! :yay:

This motor is advertised with the same bore and stroke as a crf230. Which makes it a 223. (65.5 x 66.2 mm bore x stroke) Would need to measure to confirm.

This cylinder is sleeved at 69mm which should (math be right) make 247cc motor. I *thought* that this was a CB based unit and not a CG based???

Attachment 7650

No. The 200 and 230 use a 15mm wrist pin. This cylinder/piston kit has a 17mm wrist pin.

Not too strange- witness spud riders "yamazong".

How did the sprocket alignment turn out? Do you have rear wheel bushings that can be adjusted (washers,sanding to remove thickness etc,etc)

I don't claim to be a mechanic by any means, but if you start messing with the internals of Chinese engines, it will prove your friends right. These engines are best left to sprockets, exhaust, and carbs...just posting this as a precaution, not to necessarily discourage you, because I am very curious to see how reliable these bikes can be.

Yeah, Spud's yamazong is partly to blame for my confidence in the Zong clone.

Still not sure how to proceed. The sprocket wants to run right on top of the retainer groove. It seems like cutting another retainer groove would weaken the shaft too much.

Considering trying to find some starlock washers that fit the shaft tightly; put one on each side of the sprocket.
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The rear sprocket already rides pretty close to the swingarm, plus it aligns with the chain wear guide in its current position.

Well, I already have a larger exhaust header and a Supertrapp muffler and I started it up with the new carburetor I bought from Honda for my xr200.

The plan is to leave it stock for now, but eventually I'd like to put the 247 cylinder on it and see if a Torker 2.0 camshaft will fit or if I can get one ground by WEB. We enjoy building these little motors as much as riding them. From what I can see there is no reason these cannot be built in similar fashion to a Japanese motor.

The new camshafts available for the 230 and 200 series really wake these little motors up; the 89a cam in my 200 didn't hurt bottom end at all, but gave me a nice boost through the mid-range and much more pleasant over-rev.

i thought the same, you wouldn't catch me tearing into a factory built engine. with my luck (and lack of skills) i would ruin it in no time.

not saying anything about chonda ability. sounds like he is completely confident in the process.

Thanks for this info!

I checked their page, but it says they are out of stock. For $89.95 it must be gooood!

Maybe I can build an offset sprocket using the 428 part that came with the motor, then drilling/machining the center out of a 520 such that the retainer can still bolt up?? I may just try this.

Sorry, I was wrong; it is a CB-based motor. I think I was tired when I wrote CG.

I'm with you on the math, but I have one CB motor that is incorrectly stamped. The only way to know is to measure the stroke yourself (as you say). So cool that you might hit 247!

Wired everything up today and put the "magic" button on the handlebars. Starts right up and runs great! Haven't ridden it yet, just sat on it and imagined some.

I want to change the oil first thing and get the sprocket figured out before I venture too far. This bike is plated and insured so I'm jonesin to get it back on the road.

Also need to figure out a good way to mount the starter solenoid. Will post some pics when its figured out.

Move your rear?
 

Nice crossbreed build. For the sprocket alignment, do you have enough clearance on the right side of the rear tire to move the hub over? Even if not the full 8mm, any shift would be good. If you don't have spare hub spacers laying about to play with, find a nice fat washer to add to the left side and cut/grind the same amount off the right side spacer.

Having said that, considering the distance between sprockets I'm not sure that the misalignment would really be an issue. A bit of wear will occur on the sides of the sprockets until the 3 components wear in to each other, but how long do chains & sprockets last anyway?

Jay (more than slightly off center).

The rear sprocket would actually need to move the other way. I'm not sure it will help to change the whole alignment of the rear tire and brakes, etc.

I'm more than slightly off-center too!! :) :D

First Ride!!!
 

Well, I took her for a spin tonight! Ran real good; I just let the sprocket ride wherever it wanted to and didn't notice anything bad that was chain related. That was just for this little test ride. I didn't even bolt the tank or seat down.

Rode over to a buddys house to show him the Chonda was alive! The first 4 gears are tight and low and very similar to the Honda 6 speed that used to live in that space. 5th is a pretty big drop, which I like; sorta like a wide ratio WR transmission. Overall I think it needs a little higher gearing. It pulls much harder than the worn out 200 for sure!!

On my way home I took the scenic route to get a few break-in miles on her. That is when trouble began to brew. The bike has a Voyager dash with a spark plug temperature sensor built in. Here is the dash trend:

Attachment 7660

As you can see it hit 407 F!!

Ambient in my shop was 75F:

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So I pulled the plug, which was tough to get a good picture of being hot and all:

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It looks like it is running a bit too lean.

Need to buy some bigger jets for the PD27!!

Some pictures of the motor installed for the curious.
 

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As you can see in the above picture the starter solenoid also needs a mounting bracket made.

Dumped the oil while it was hot so I can get some better stuff in there.

Does anyone know what temperature these motors should run at?? Over 400 seems too high.

No idea what temp it should run at; never tried to measure. Perhaps you'd like to try the carb you had on your XR200 motor. I'll bet it's a Keihin. What are the jet sizes in it?


If you feel like splitting the case, I'd be inclined to believe the XR200 six speed will drop into the CB case. You're used to those gears.


Thanks for the install pics! :D

as an fyi, my CB200 (163fml pushrod engine) runs right on the 340-365 range when I am riding... and that's pushing the wngine a bit... if I really flog it, I will see 375-400, and given new engine and tight parts, 400 isn't out of the realm of possibility, however I think your temps will come down a good 50 degrees with a fatter main jet...

This is the carb off the 200! Its a factory Honda Keihin PD97 that I bought about 8 months ago because I was tired of dealing with worn out crap. It worked really well on the 200.

The jetting is stock. I believe the main is a 110. Perhaps with the bigger motor it needs a richer main. Especially with the bigger exhaust and large air filter. (Both of which were on the 200) I think the pipe is an old Powroll design.

Awesome info!!

Those are more like what I would expect.

I tore the carb top off last night and richened the needle position by moving the clip down 2 notches. I'll try it again tonight and see if it runs cooler. It also has fresh Mobil1 V-twin in the case now.

Your sig indicates that you also have an early XR200. Can you remove the carb and check the jetting, just for giggles? IIRC, the stock main on an XR200R is closer to 130, but I could be way off. What elevation are you at?