Zongshen GS250 - Clutch + other issues

[TheBeege]

Hey guys,

I'm hoping someone else has encountered something similar. I'm still a new rider, so pardon any lack of precision or jargon.

I'm having issues where I don't think my clutch is fully engaging. When I pull in the clutch and roll the throttle, I still get some push. With my previous (read as "first") bike, engaging the clutch completely cut off any engine power to the wheels. Is this a configuration issue, i.e. tightening or loosening something? Is this potentially a bad part? Is this expected behavior for this bike? It's also remarkably difficult to shift, finding neutral is a pain, and when releasing the throttle and engaging the clutch, it revs down instead of running freely (I'm sure there's a better way to say that).

My headlight also died on me last night on the freeway. Fortunately, the bright was working. It was flickering before it died, so I'm thinking it may be a wiring issue instead of bulb issue? Then again, I have no idea what I'm talking about. (EDIT:) Also, the distance the headlight casts is terrifyingly short. I only got maybe 20ft of illumination in front of me. I was terrified there would be debris in the road, and I'd be done for. Is that normal, and/or is there any way to adjust it? (/EDIT)

If you're not familiar with these issues specifically, I would greatly, greatly appreciate any learning materials or direction on how to better diagnose things. My background is in IT, and I have very, very little experience with machines that aren't computers.

Thanks!!

[Weldangrind]

Machines are machines. With the right tools and a sense of humour, you can certainly maintain your China bike.

Your clutch just needs a little adjustment. Start with the adjuster at the clutch lever; loosen the large nut that tightens against the perch, and then loosen the entire adjuster a few turns. Whne you pull on the lever, you should have a little freeplay, which shows as a slight gap between the lever and perch before you feel resistance.

Right now, your cable is not tight enough, but take care to not tighten it too far. There should always be the gap that I spoke of, not a terribly rigid lever.

Please show us pics of your headlight assembly, and we can guide you from there.

[TheBeege]

That's good to hear. Now, I just need to get tools hah. I'm lucky enough to live walking distance from a hardware shop.

So here's the clutch lever:
http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/20140925_092912.jpg

Here's a parts photo of the cable...
http://www.china-parts.co.uk/acatalog/CA017031L.JPG

In the parts photo, the round, black rubbery thing on the left is the adjuster? And the nut is the gray ring between the adjuster and the lever assembly?
Assuming these are right, I played with it a bit. When tightening it and loosening it, it either wouldn't completely leave the gear (shifting into first would propel the bike even when the clutch was pulled in) or it would be very difficult to actually shift gears. I forget which was tightening and which was loosening. I can go play with it again.

Is there anything that should be done on this end of things?

http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/20140925_092921.jpg



Here's the headlight assembly:

http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/20140925_092902.jpg

http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/20140925_092857.jpg

It actually flickered then turned on when I started her this morning:

http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/20140925_093104.jpg

This is with the brights on:

http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/20140925_093117.jpg

I can't discern any difference between the two. The fact that it's flickering still makes me think it's a slightly loose wire. I did find a wiring diagram elsewhere on this site. I saved it to my Drive just in case it disappears. I'm not sure I could relate this diagram to the actual wires in the bike. Is it meant for that, or is it intended to provide just a logical explanation of connections?

http://i21.photobucket.com/albums/b295/DictatorDraco/Zongshen/ZS250GSwiringdiagramjpg.jpg




Also, it's occasionally been... skipping? I'll be riding and it'll act as if it's shifting - throttle will cut for a second then come back a little stronger. It happened again this morning when I was trying to get her back into neutral. I noticed the little red battery light blink when it happened. Is this something to worry about?

Thank you so much for taking an interest!!!!

[Weldangrind]

You nailed it. Pull the rubbery thing back to reveal the adjuster. Keep working at it, and you'll likely resolve it. If you need to back it out almost completely, then we'll move to the other end of the cable.

You should dismantle the headlight enough to remove the bulb. My guess is that the bulb is loose in the socket.

Pull the spark plug and tell us what type it is.

[TheBeege]

Woo! Thank you! After experimenting with the adjuster near the lever, I wasn't able to get a result I was happy with. I started playing with the other end, and I found the right spot in no time :D She's now easy to shift, and the clutch fully engages when I pull it. Use this video to manage the lever-side of the cable:

https://www.youtube.com/watch?v=diF4XN0OxMI

Took at look at the headlight assembly... I'll have to completely take off the two front fairings to access it. Not a big deal, but it'll take time. I'll see if I can tackle that today after running errands.

How can I tell what type of spark plug it is? I'll probably just take a picture and post. Found this video:
https://www.youtube.com/watch?v=VPm_Z92FgCw
Those all sound like the right way to do things?

[culcune]

Actually, as far as spark plugs go, one of your own photos in your intro post tell you what kind of spark plug to get. On the right swingarm, there is a sticker which states "Vehicle emission control information Zongshen Inc" and on there it will tell you what kind of plug your bike needs and the gap to make it. Even if the plug looks ok, it couldn't hurt to start with brand new ones. On my bike, it is VERY easy to get to the plug, but be careful pulling on the spark plug 'boot' since if you break something, a Zongshen replacement might not be as easy to find vs. finding a common Honda or Suzuki.

Is this a single cylinder or a twin cylinder? You might need two spark plugs...

[humanbeing]

...Is this a single cylinder or a twin cylinder? You might need two...
Single / Big bored (72.5) Yammie clone. SAME NGK D8EA (& compatibles cross ref to that model ) as Sierra.

[Weldangrind]

Woo! Thank you! After experimenting with the adjuster near the lever, I wasn't able to get a result I was happy with. I started playing with the other end, and I found the right spot in no time :D

Happy to help. :D

Looking forward to pics of your plug.

[culcune]

Single / Big bored (72.5) Yammie clone. SAME NGK D8EA (& compatibles cross ref to that model ) as Sierra.

OK, thanks for clarifying for me the engine. I had thought these were twins, but once he started discussing his more and more, I wasn't so sure.

If you look at the emissions sticker in his photo, you can almost make out "D8EA" which most of these seem to use.

[Weldangrind]

It's essentially the same as Spud's Zong and the TW200, with a slightly larger bore.

[SpudRider]

Yes, your GS250 employs a D8EA spark plug, and a TW200 clutch cable, the same as my Zongshen ZS200GY-2 (Sierra). :)

[culcune]

It's essentially the same as Spud's Zong and the TW200, with a slightly larger bore.

I wonder how much trouble it would be to put one of these engines in a Sierra :) ?

[Weldangrind]

I wonder how much trouble it would be to put one of these engines in a Sierra :) ?

Not a big deal. The cylinder head from the Sierra would be required, to make the exhaust exit the right side of the engine, but that's the only mod required.

[SpudRider]

I wonder how much trouble it would be to put one of these engines in a Sierra :) ?

I believe the ZS172MM engine in the Zongshen GS250 has the same stroke (55.7mm), but a larger bore (72.5mm) than the ZS167FML engine of the TW200/ZS200GY-2 engine, which has a bore of 67.0mm.

You could bolt the entire ZS172MM engine in the Sierra's frame, but you would have problems with the exhaust header. Personally, I wouldn't want to mess with it. Because the GS250 engine has a larger bore, you can't put the smaller cylinder head of the TW200/Sierra on the ZS172MM engine. ;)

[Weldangrind]

Because the GS250 engine has a larger bore, you can't put the smaller cylinder head of the TW200/Sierra on the ZS172MM engine. ;)

Please explain. I don't understand why the Sierra head is incompatible with the larger bore, given the same frame of architecture (FOE). The small block Chevrolet SBC) engine will allow any head to interchange with any block, from 265ci to 400ci. The only real difference is cylinder head volume. The bolt spacing remains the same.

The only real issue that comes into play with the SBC is that the FOE is such that the valves are shrouded with anything less than a 4" bore, but the engine will still run properly.

A larger bore in the Zong engine would give the valves even more space. I doubt that the cylinder volume is dissimilar between the two heads. As long as the dowels line up, I can't see a problem.

[SpudRider]

You are probably correct. ;) I'm assuming the bolts won't line up, and/or the larger cylinder bore won't mate, or seal properly with the smaller volume of the 196cc cylinder head.

[Weldangrind]

I can confirm that the studs line up, but the dowels are smaller on the Zong. Back to the lab.

[TheBeege]

Sorry for disappearing XD As mentioned in the other thread, work's been killing me.

Pardon my ignorance, but can you guys suggest somewhere a layman could read up on "stroke" and "bore" and other engine bits?

[SpudRider]

Sorry for disappearing XD As mentioned in the other thread, work's been killing me.

Pardon my ignorance, but can you guys suggest somewhere a layman could read up on "stroke" and "bore" and other engine bits?

The bore of the cylinder is the diameter of the piston. The stroke is the distance the piston moves in the cylinder. ;)

Here is an excellent website for learning more about motorcycles. Brother Dan is an Idahoan, and an excellent teacher. :tup:

http://www.dansmc.com/mc_repaircourse.htm

[humanbeing]

http://www.ehow.com/about_6460291_bore-stroke-motorcycle_.html

[Weldangrind]

Pardon my ignorance, but can you guys suggest somewhere a layman could read up on "stroke" and "bore" and other engine bits?

That's an excellent question, and we all started somewhere. These gentlemen provided good resources for you, and I encourage you to read them.

To further the discussion, remember the lessons on volume of a cylinder in middle school math? If you measure the volume of the cylinder (in millilitres) when the piston is at the bottom, you'll get the size of the engine. A millilitre is the same volume as a cubic centimetre, so 250ml = 250cc.

If you measured the cylinder of a car (again, with the piston at the bottom) and then multiplied by the number of cylinders, you'd get the size of the total engine. As an example, if the volume of one cylinder multiplied by six cylinders = 3000ml, that is where we get the expression of a 3 litre engine. In case you're not as familiar with metric, 1000ml = 1 litre.

[TheBeege]

Ahhhh, this all makes very good sense, now. Thank you guys!!!