what is this GY200?

[TommyD]

I was not able to get the valve cover completely off on mine due to the frame and large welds interfering. Your engine SHOULD be a push rod type if it's a mid 2000's model. I'm recovering from a flu bug but hope to get my engine out this week. Sounds like we'll be working on our Jialing's at about the same time!

Here's a photo of mine:

[rjmorel]

So popped the valve cover off today. Nothing looked trashed. Exhaust valve had no wiggle while intake did. So will adjust them soon and see if it starts up. rj

[Weldangrind]

Is it a CG pushrod motor?

[rjmorel]

Yes I believe so. I can see 2 rods coming up from left side of motor that push on the rocker arms. There is no chain or cam shaft on top anyway. I'm not real familiar w the push rod type of motors. Are they good ,bad or?
Slow going as I'm self-annoyed with a plastic injection molding business and my son and I are trying to stay up with orders right now running machines so bike is a back burner project.
So far only mechanical damage I've found is the hose from cylinder head to the emission thingy was burnt badly in 2 and the exhaust heat was melting the bottom of gas tank. Not sure if that means anything evil mechanical wise but I think I will remove it all together and plug port on carb and hole coming out of cylinder that emission gizmo connects to. The cylinder hole is black with exhaust carbon. to be continued, rj

[Weldangrind]

Sounds like one the much-beloved CG pushrod motors; they're one of my guilt pleasures. The TT250 and the Hawk (among many others) use that motor, and parts are easy to find.

[rjmorel]

Alrighty then, after work my son and I adjusted the exhaust valve using a .003 thou feeler gage which is close to .07 mm I think. The valves are probably now at around .004/.005. Didn't adjust the intake valve as it was probably .005/.006"
It fired up and ran for a bit but we didn't have gas tank on it so probably ran out of fuel.
The tick noise went away I first heard.
We plugged off the 1/4" hose from carb with a dowel and had the hole coming out of the cylinder head open and exhaust came out of it and smoked a rag we held over it.
So a couple of questions?
1) What should I set valve clearance at? Are both the same?
2) I'll make a plate to cover the Air recirculation thingy hole in the cylinder head so exhaust wont come out. I'm assuming that it is a direct hole into the exhaust port so exhaust will come out?
3) On the header pipe below the spark plug is a fatter part maybe 4" long inline with the header. Is that the catalytic converter?
4) Now that it ran, how noisy are these motors because I think I hear noise from bottom end like noisy crank bearings but don't know if this is normal to these motors or not.
5) After we plug the air recirc hole in head we'll put tank on and see if we can just run it sitting there for 3-5 minutes and see what it sounds like after sitting for the past 1 1/2 years.
6) I can kick start it but trying electric start just sucks battery down and wont start with electric starter
7) do these have a counter balance in the motor?
Anything else we should check on it?
Thanks for all your help guys, Rob

[Azhule]

1) For these push rod motors I always did what CSC recommended and set the valves as close to 0.07mm as I could get.

2) Easy enough to make a block off plate for that "exhaust/emissions port"

3) That "EGG" sometimes has what some consider a "Catalytic Converter" stuff inside it, the way the exhaust bends sometimes the only way to know is scope it with a camera or cut it open

4) I hear some "tics, hums, and warbles" when our bike is running, but these engines are not built to be "luxuriously quiet" after all, more like "Honda Type R" engines from the 90's... lots of random things you can hear, lets you know the C-Tech is working but without actually hearing your engine I have no clue if those sounds are "normal" or not

7) Can't see the "counter balance" from the first pic you posted up, but I do need glasses for a reason

[rjmorel]

I also noticed tonight rear wheel was missing 3-4 spokes. How'd that happen in 375 miles? Where can they be bought from? The nipples are still in the wheel and its holding air, so we got that going for us. rj

[Weldangrind]

Since Azhule answered your questions, I'll just add / ask a couple things.

Where does the 1/4" hose connect to the carb? I'd be curious to see that.

Where does the large vent hose on top of the motor (just below the carb) connect?

Spokes might be the same length as old XR200 18" rims.

2. That is actually a port designed to receive fresh air for a more complete burn. I don't think it actually works, which is why most of us ditch it. Mine came with a plate from the factory.
3. Try chasing something down the header to see if you feel a major restriction. Perhaps some mechanic's wire. If there's a cat in there, cut it out. If you do, I recommend cutting maybe 3/4 of the way around, so you don't change the angle or length. After gutting the cat, you can weld the piece back on.
4. They're noisy, but more from the top end.
7. Yours does not have a CB.

[rjmorel]

Weld, 1/4" hose attaches to top of rubber carb manifold in front of carb, not to carb , my bad.
Large vent hose connects to cylinder head RH side ,not valve cover, just in front of spark plug. rj

[Weldangrind]

May we see a pic of where the large vent hose connects to the cylinder head? I'm quite curious about that.

[rjmorel]

the hose is burnt in two just above where it goes into the cylinder head. The other large hose goes back under seat by left turn signal and has a filter on it I think. The smaller 1/4" hose with wire wrapped around it above the valve cover goes to top of intake manifold. rj

[rjmorel]

Now that I learned how to insert pics from my computer, here we go.





In pic #3 anyone know what the elongated holes are for in the bracket attached to the fork leg?


pic#4 gas tank damage from broken hose letting exhaust heat up plastic tank.

[Megadan]

That broken hose connection on the cylinder head looks to be part of the air injection system that introduces fresh air to the exhaust. That whole shebang can be removed if you so desire it. You just need to make a block off plate for the head where that hose fitting bolts on. You can then remove the rest of that system if you so desired, and simply cap off any open connections.

[rjmorel]

Where there some problems with chinese bikes breaking rear spokes? Mine has about 6 broke with 375 miles on it . Bike doesn't appear that it was riden by Evil Knievel so was wondering if they over tightened or used wrong bend from factory or swapped inside for outside spokes? rj