New member! Help me tell what cc my zongshen motor is???????

[Ironmike]

Originally Posted by JerryHawk250

Did you check the oil if the Seafoam leaked down into the base? Oil may be thinned out from the Seafoam. From they way it sounds you may want to do a teardown before any more damage is done if there is some kind of mechanical issue.

Cant tell if it leaked down in the oil. If it did its small amount. Im gonna change the oil today and see if it helps? If not gonna tear it down. If i have to end up rebuilding whole topend can i bolt on a 250 topend/head? is the 200cc and 250 head the same? Thx

[humanbeing]

200 / 250 head use different valves:

CG250: 34 / 28 according to https://item.taobao.com/item.htm?id=555896190292

[Ironmike]

Originally Posted by humanbeing

200 / 250 head use different valves:

CG250: 34 / 28 according to https://item.taobao.com/item.htm?id=555896190292

Ok so what do i need to make this a 250(230) ? Are the push rods/rockers the same? If im gonna rebuild it might as when get a little more power. Plz advise!

[Weldangrind]

The case mouth is likely to be larger on a 230 and the connecting rod small end might also be larger. If you buy a cylinder, piston and head, you'll be able to measure the difference to be sure. Some careful work with a die grinder will allow you to open up the case mouth, but the risk is shrapnel in the bottom end. After all of that, you could find that the rod is too short to bring the piston to the deck, although I doubt that.

[Weldangrind]

Really, you're better off finding a used 230 and dropping it in. There were several different models of dirt bikes and dual sports that used that engine over the years, up to and including the Hawk and the TT of today.

[Ironmike]

Ok figured id ask. Not worth the hassel. Ill just fix whats wrong with this motor. Never gonna be a speed demon anyway. I always look for that little extra in every machine i own

[Ironmike]

Is there any other bigger cc china motor that uses same mounting points as this 200? Something bigger then 250?

[Ariel Red Hunter]

Originally Posted by Ironmike

Cant tell if it leaked down in the oil. If it did its small amount. Im gonna change the oil today and see if it helps? If not gonna tear it down. If i have to end up rebuilding whole topend can i bolt on a 250 topend/head? is the 200cc and 250 head the same? Thx

If someone on here would offer Ironmike a junk 230cc cylinder, he could tell if that cylinder would fit his crankcases, and if the hold down bolts are located the same. And the oilfeed to the rocker gear. The head is different....ARH

[Ariel Red Hunter]

Originally Posted by Weldangrind

The case mouth is likely to be larger on a 230 and the connecting rod small end might also be larger. If you buy a cylinder, piston and head, you'll be able to measure the difference to be sure. Some careful work with a die grinder will allow you to open up the case mouth, but the risk is shrapnel in the bottom end. After all of that, you could find that the rod is too short to bring the piston to the deck, although I doubt that.

I think that they both have the same stroke...ARH

[Ironmike]

Originally Posted by Ariel Red Hunter

I think that they both have the same stroke...ARH

or if someone has a decent running 250 forsale? Ill update you guys later tonight if i get the time to take it apart.

[Megadan]

The only way to know if the CG250 67mm cylinder jug would work on the 200 case would be to pull the 200cc jug and measure the outer diameter of the cylinder sleeve. If I remember correctly, the CG250 sleeve is 72.5mm where it enters the crankcase.

The only other real factor to consider is knowing what your wrist pin diameter is if you decide to order a cylinder and piston kit, so the motor would have to be torn down in either case. If you really wanted to experiment and find out if it is possible, then you would only be looking to invest about $60-70 for a piston and cylinder kit.

Otherwise, I agree with Weldandgrind, it would likely be a much easier/better option to snag a used CG250 and rebuild that for your bike. I've seen a few on ebay from time to time usually selling for a couple hundred bucks.

[Ironmike]

Udate! Come to find out the leak down tester i used was faulty. Used a different one and got a air leak coming out the oil filler hole(bad rings) took it apart and had no stuck rings. Piston measured 63.46mm, top of cylinder varied from 63.45-63.56, bottom of cylinder 63.37-63.42. Noticed a long scratch in cylinder and some lighter scratches on piston. Take a look at the pics and tell me what you guys think? I can feel the long scratch with my finger nail but not crazy. Wrist pin didnt slide right out. Had to use screw driver and tap it out a bit . Is that normal? The rod looks fine.

[Ariel Red Hunter]

Originally Posted by Ironmike

Udate! Come to find out the leak down tester i used was faulty. Used a different one and got a air leak coming out the oil filler hole(bad rings) took it apart and had no stuck rings. Piston measured 63.46mm, top of cylinder varied from 63.45-63.56, bottom of cylinder 63.37-63.42. Noticed a long scratch in cylinder and some lighter scratches on piston. Take a look at the pics and tell me what you guys think? I can feel the long scratch with my finger nail but not crazy. Wrist pin didnt slide right out. Had to use screw driver and tap it out a bit . Is that normal? The rod looks fine.

Ideally, I'd replace the cylinder and piston and rings. At a minimum, I'd hone the cylinder in a cross hatch pattern and replace piston and rings. Piston has to be replaced because you will never get all of the grit that's in the piston skirt cleaned out of it. From the pics, it looks like the top ring has been hammering the groove too wide. Also the three piece oil control ring is either worn out or has lost its temper. As much grit is in that engine, I'd flush the crankcase out with a couple of gallons of kerosene, without running the engine. Also check and clean out the oil luberifiner next to the clutch, under the right side crankcase cover. Then, after you put it back together, change the oil at least two times after you get it running....ARH

[Ironmike]

Originally Posted by Ariel Red Hunter

Ideally, I'd replace the cylinder and piston and rings. At a minimum, I'd hone the cylinder in a cross hatch pattern and replace piston and rings. Piston has to be replaced because you will never get all of the grit that's in the piston skirt cleaned out of it. From the pics, it looks like the top ring has been hammering the groove too wide. Also the three piece oil control ring is either worn out or has lost its temper. As much grit is in that engine, I'd flush the crankcase out with a couple of gallons of kerosene, without running the engine. Also check and clean out the oil luberifiner next to the clutch, under the right side crankcase cover. Then, after you put it back together, change the oil at least two times after you get it running....ARH

Ok. Think I'm gonna replace the valves/seals while it's apart. Any special break in process once I replace cylinder/piston/valves? I also need tq specs for head bolts/rocker assembly bolts ect I'm looking a this kit on eBay for $55. Says it comes with 2 oil seals (small blk things) are those valve seals? thx

[Ironmike]

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