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

[Ariel Red Hunter]

Originally Posted by Ironmike

That was a better vid thx. Adjusted them today. Intake was alittle tight and exhaust loose. Made up a air filter setup and it's running decent. Figures once I get it running decent it's smoking like crazy. Only a little at idle but when I give it a quick rev it smokes aaalot. I'm running 15-40. Oil was a bit dirty when I got it so I've changed the oil 4 times to clean it out. Seems to smoke more now that the oils clean. If I hold the throttle steady at mid rpm doesn't smoke that bad. I'm assuming worn rings is main cause with valve seals on there way out also. Can I just get a new piston/rings? Wouldn't mind buying piston/cylinder/gasket set all together. Maybe new head? Where's a good place to order from? Looked on eBay but not sure which will fit? Possible to make with a 229cc ? Sorry That's a lot of questions lol. Thx

You tried MarvelMystery Oil and ran it a week? You said the oil was very dirty the first time you posted. It is unlikely you need a new cylinder, but possible. You may only need new rings. You won't know until you tear it down. When you do that, I will tell you how to measure the cylinder for bore wear. But try the MMO treatment first. Don't be in such a rush to give up on it. There are people on here with 50,000 miles on these engines with virtually no wear.....ARH

[Ironmike]

Originally Posted by Ariel Red Hunter

You tried MarvelMystery Oil and ran it a week? You said the oil was very dirty the first time you posted. It is unlikely you need a new cylinder, but possible. You may only need new rings. You won't know until you tear it down. When you do that, I will tell you how to measure the cylinder for bore wear. But try the MMO treatment first. Don't be in such a rush to give up on it. There are people on here with 50,000 miles on these engines with virtually no wear.....ARH

Have not tried mmo. I haven't road it yet on the trails due to me fixing it up. It's not trail worthy yet. Just been testing it around my yard. How much mmo should I put in? Can I just start it up here and there to see if mmo works? Ya not giving up on it. Fun little project . Has come along way since I got it thx

[Ariel Red Hunter]

Originally Posted by Ironmike

Have not tried mmo. I haven't road it yet on the trails due to me fixing it up. It's not trail worthy yet. Just been testing it around my yard. How much mmo should I put in? Can I just start it up here and there to see if mmo works? Ya not giving up on it. Fun little project . Has come along way since I got it thx

5.5 oz to the crankcase, 1 oz in the gas tank per fill up. It will take about a hundred miles to really clean the sludge and varnish out of the engine. Then you will know for sure if it needs a ring job. I am guessing that the engine is varnished up in the ring grooves because of the way you described the oil you took ot of it at first. It could also be burning oil out of the exhaust system from an overly enthusiastic use of oil when the previous owner laid it up. If it was me, I'd do the full mmo treatment, then run it around the back yard for fifteen minutes or so, and then just get on with the other work you have to do to get it ready to go. Then run it 100 miles and see where you are..ARH

[Ironmike]

Originally Posted by Ariel Red Hunter

5.5 oz to the crankcase, 1 oz in the gas tank per fill up. It will take about a hundred miles to really clean the sludge and varnish out of the engine. Then you will know for sure if it needs a ring job. I am guessing that the engine is varnished up in the ring grooves because of the way you described the oil you took ot of it at first. It could also be burning oil out of the exhaust system from an overly enthusiastic use of oil when the previous owner laid it up. If it was me, I'd do the full mmo treatment, then run it around the back yard for fifteen minutes or so, and then just get on with the other work you have to do to get it ready to go. Then run it 100 miles and see where you are..ARH

Thx for the good advice. Ill pick some up today yup have alot more little things to do before its trail worthy!keep you updated!

[Ironmike]

Ok guys added the mmo. Rode it around hard few times so far. Fills yard with smoke. I know I have to give it some time . Got my airfilter in today. Here's the next problem. Jetting is way off. I've played with the mixture screw/needle but still cuts out when I rev it fast. Only runs halfway decent with the choke 80% on which I know means it's running lean. I have the mixture screw 3 turns out and tried the needle in every position. Assuming it needs bigger jets. I've googled stock size jets for china pz30 and found many different answers. Pulled main/pilot jets to see size and there's nothing written on them. I noticed on top of the carb where the throttle cable goes in there's nothing really keeping the cable in place. Usely I've seen a metal tube or theaded like screw that the cable sits in. Could this be a problem ? Is that area supposed to be air tight? I can post pics of carb top if needed.I seen this carb/jet kit while googling. Should I just order both? Let me know thx

[Ironmike]

Carb pic

[Mudflap]

My Zongshen 167FML with a PZ30 carb used a 110 main and a 38 pilot.

[Ariel Red Hunter]

Originally Posted by Ironmike

Ok guys added the mmo. Rode it around hard few times so far. Fills yard with smoke. I know I have to give it some time . Got my airfilter in today. Here's the next problem. Jetting is way off. I've played with the mixture screw/needle but still cuts out when I rev it fast. Only runs halfway decent with the choke 80% on which I know means it's running lean. I have the mixture screw 3 turns out and tried the needle in every position. Assuming it needs bigger jets. I've googled stock size jets for china pz30 and found many different answers. Pulled main/pilot jets to see size and there's nothing written on them. I noticed on top of the carb where the throttle cable goes in there's nothing really keeping the cable in place. Usely I've seen a metal tube or theaded like screw that the cable sits in. Could this be a problem ? Is that area supposed to be air tight? I can post pics of carb top if needed.I seen this carb/jet kit while googling. Should I just order both? Let me know thx

No, the part of the carb where the cable goes in is not considered (by us) as part of the airtight part of the carb. The air leaking by the throttle slide was factored in the original design. I would definatly suggest that you only buy genuine Keihin jets. The aftermarket jets are not as accurately sized. Which makes tuning more frustrating than it already is. As to not responding well when you whack the throttle open, that is because these carburetors are not designed to work that way. They are desingned to work better in the roll-on mode. There are three ways to get better snap acceleration. A one or two step richer pilot jet, a throttle valve with less cut-away, and raising the float level a hair at a time. Unfortunatly, only the Mikuni offers different slide cut-aways. Also the Mikuni genuine jets are easy to find on the internet. So, if you remember that the idle air screw controls idle mixture only, that the pilot jet controls fuel mixture from just above idle to 1/4 throttle, the needle from 1/4 to 3/4 throttle, and the main jet from 3/4 to wide open, you will be on your way....ARH

[Weldangrind]

Mike, have you had a look at the vent hose? Ensure that it is free from obstructions and that it is not kinked.

[Ironmike]

Originally Posted by Ariel Red Hunter

No, the part of the carb where the cable goes in is not considered (by us) as part of the airtight part of the carb. The air leaking by the throttle slide was factored in the original design. I would definatly suggest that you only buy genuine Keihin jets. The aftermarket jets are not as accurately sized. Which makes tuning more frustrating than it already is. As to not responding well when you whack the throttle open, that is because these carburetors are not designed to work that way. They are desingned to work better in the roll-on mode. There are three ways to get better snap acceleration. A one or two step richer pilot jet, a throttle valve with less cut-away, and raising the float level a hair at a time. Unfortunatly, only the Mikuni offers different slide cut-aways. Also the Mikuni genuine jets are easy to find on the internet. So, if you remember that the idle air screw controls idle mixture only, that the pilot jet controls fuel mixture from just above idle to 1/4 throttle, the needle from 1/4 to 3/4 throttle, and the main jet from 3/4 to wide open, you will be on your way....ARH

Ok on carb top. Ill post a pic to show you guys anyway. Ive had many pitbikes and throttle respose on those have been waaay better. When i say breaks up when reved it basicaly cuts right out where motor almost stalls. I have a little experience with jetting . Takes a bit to get them dialed in but this setup seems to be way off for some reason.

[Ironmike]

Originally Posted by Weldangrind

Mike, have you had a look at the vent hose? Ensure that it is free from obstructions and that it is not kinked.

I dont see a vent hose on the carb?

[Weldangrind]

It's not on the carb. It's a hose that is connected to the top of the engine (underneath the carb), and then it usually routes down behind the swingarm and points at the ground. It must not be kinked or plugged.

[Ironmike]

Originally Posted by Weldangrind

It's not on the carb. It's a hose that is connected to the top of the engine (underneath the carb), and then it usually routes down behind the swingarm and points at the ground. It must not be kinked or plugged.

Oh ok. I know its not kinked but ill check if its plugged. Thx

[Ironmike]

Ok had some time to work on atv today. I put a 105 main in. Stock didn't have a size on it but I used the drill bit method and it was smaller then a 105. I tried 40,42,45 piolet jets and it runs best with the 45. I have mixture screw 2 turns out and needle in the middle position. Response is a lot better but still needs tunning. How does this carb setup sound to you? Only thing different from stock is 6" long hose of carb with clamp on air filter. Wants stock needle position? The vent tube off motor is clean and not kinked. Still smoked like a mother. Hard to read the plug due to that. Thx

[Ariel Red Hunter]

Originally Posted by Ironmike

Ok had some time to work on atv today. I put a 105 main in. Stock didn't have a size on it but I used the drill bit method and it was smaller then a 105. I tried 40,42,45 piolet jets and it runs best with the 45. I have mixture screw 2 turns out and needle in the middle position. Response is a lot better but still needs tunning. How does this carb setup sound to you? Only thing different from stock is 6" long hose of carb with clamp on air filter. Wants stock needle position? The vent tube off motor is clean and not kinked. Still smoked like a mother. Hard to read the plug due to that. Thx

Just curious. What color is the smoke?...ARH