Idling problem with my Kinroad

[Rooby]

Hellow guys, I have a little issue with my kinroad (the exact model is xt200-18 Strong Wind) which camed with a 163fml engine similiar to most chinese motorcycle motors..
The problem is that when i first try to start it (at full chocked) it starts well but i have to keep it from acceleration otherwise the idle speed slow down under 1k and before that it struggle a little bit and die...
If i keep it accelerate a little bit on full cocked and than swhitch to half way open the rpms suddenly increase and then after 4-7 sec stay around 1,5k..
The problem is that when i switch to no chocked from half way chocked the rpms drop around 1k and it seem that it is struggleing a lot just to keep the motor runing and i have to keep it from acceleration because if i let it without it i just dies...
If I warm the motor around 5 minutes it seem to stay around 1-1,5 k at no chocked position but when i try to accelerate suddenly the rpms decrease (sometimes it dies) and just before that the motor respond, it is something like a big hesitation in the throtle system...

I want to add that the carb (pz30 chinese carb) is super-clean and it has no leaks...
The fuel mixing screw is on 3 turns out ( from factory it was only at half a turn out) and the idle screw is thight almost completly..
When i ride it it has no problems except that somethimes when i pull the clutch the motor dies...
Also i want to add that i remove the spark and it is black....
The bike is new (i am the first owner) what could be the problem?

Thank you!

P.S :sorry for my bad english, I am from Romania

[katoranger]

If your plug is black then it is running rich. Get a new plug to start. Weld is better at carb tuning, but it sounds like you need to make some adjustments. 3 turns on the mixture screw is alot.

Idle speed of 1000-1500 rpm is normal.

What elevation are you at? These bikes are usually jetted lean and with the carb c-clip set at a leaning setting. Moving the c-clip a notch might help with starting.

[Ranbo]

I had a similar issue with my bike a while back. It turned out to be a vacuum leak. I had a small vacuum hose with a spilt where it connected to the intake between carb and the motor. I ended up just capping it off right there. I also got rid of all my emissions junk as I don't need it to be legal.

[Rooby]

Originally Posted by katoranger

If your plug is black then it is running rich. Get a new plug to start. Weld is better at carb tuning, but it sounds like you need to make some adjustments. 3 turns on the mixture screw is alot.

Idle speed of 1000-1500 rpm is normal.

What elevation are you at? These bikes are usually jetted lean and with the carb c-clip set at a leaning setting. Moving the c-clip a notch might help with starting.

Thats what i think too, but if my mixture is too rich when i move the c-clip for more fuel it will run even richer no? My c-clip is at the middle, this was the factory setting...

I`ll try a new spark plug in this morning and see how it run with it..


And Ranbo, i have a similiar emmision reducer mounted on it, i`ve tried blocking it but didn`t make any diference at all so i let it there..

P.S: anybody knows the regular position of the mixture screw? (i`ve heard that it is around 2 turns out, but i know that it is different for bike to bike)




UPDATE: i`ve try with a new spark plug and it is no difference at all!

[katoranger]

Two turns for the mixture screw sounds about right. If it does not run well then the jetting or possible carb air leaks may need to be looked at.

You may need to move your c-clip to a leaner setting. I don't know what elevation above sea level Romania is, but that can have alot to do with how it runs.

It the spark plug original? Using a NGK or other quality plug may just fix the problem.

[Rooby]

Originally Posted by katoranger

Two turns for the mixture screw sounds about right. If it does not run well then the jetting or possible carb air leaks may need to be looked at.

You may need to move your c-clip to a leaner setting. I don't know what elevation above sea level Romania is, but that can have alot to do with how it runs.

It the spark plug original? Using a NGK or other quality plug may just fix the problem.

The spark plug is original but i`ve try in the morning with a ngk and it wasn`t no difference...
Despite the fact that the spark plug is black it seems to me that it run lean because when i accelerate quickly the motor just die...something like a little hesitation..
In Sibiu the Elevation above sea level: 401 m = 1315 ft

[katoranger]

What you describe makes it sound lean too other than the black plug. Try moving the clip once slot down. See if that helps.

[Rooby]

Originally Posted by katoranger

What you describe makes it sound lean too other than the black plug. Try moving the clip once slot down. See if that helps.

K...i`ll try that tommorow to see what happens, thank you a lot!
I want to hear more opinions so if you have something in mind that could cause that problem don`t be afraid to post it here ...

[Rooby]

Ok, I`m back with fresh info..
I`ve tried to move the clip but seems that it had no effect...

Any ideas?

[Rooby]

Nowbody? :(

[FastDoc]

Have you checked for an air leak in the induction system between the carb and the inlet tract? VERY common issue on these bikes and it would explain your symptoms.

Also, if that is not the case, good advise (Thank's, Weld :-) would be to swap the carb for a $40 Mikuni and call it victory.

[Rooby]

Originally Posted by FastDoc

Have you checked for an air leak in the induction system between the carb and the inlet tract? VERY common issue on these bikes and it would explain your symptoms.

Also, if that is not the case, good advise (Thank's, Weld :-) would be to swap the carb for a $40 Mikuni and call it victory.

Thanks`s for advice but it seems that their are no leaks....
I didn`t want to change my carb.....in fact it is brand new, I doubt that it can`t be not repair/adjusted...

I would apreciate other sugestions.

[Weldangrind]

The reason I often suggest a 30mm Mikuni, is that finding replacement jets for the PZ30 carbs can be difficult. Since you need to have your pilot mixture screw turned out three full turns, the slow jet is likely too small. It's very easy to find replacement jets for a Mikuni, but I've seen a few different styles of PZ30 that do not share jets.

This 30mm Mikuni has free shipping to Romania: http://www.ebay.com/itm/Carburetor-C...20c32b&vxp=mtr

The truth is that I've changed the PZ30 carb to a 30mm Mikuni on every China bike or ATV that I've owned or worked on. They make life easier.

[edtardo]

I agree with weld. Get the Mikuni and be done with it

[zingshoen]

hello romania! i would check the valves first. often they are too tight. when you know the valves are good, you can start with the carburettor.

after that it could be that your idle is too rich, your mid range too lean, your main jet too small, but the bike should run, maybe not perfect, but useable, with your current carbie and a standard setting. there are only a few variables on the carbie, you ll work it out.