pw50 can't breath

[cope]

I have a PW50 2001
It has had problems in the past, but let just get to the point. the bike runs great without the airfilter on (just the open intake to the carb) the moment i put anything infront of intake it will bog down and stall. carb has been soaked for cleaning, fuel/air mixture has been adjusted to see if it would ruan any bettter, and I even checked to see if reeds are clean of any debris. The cylinder has been changed along with piston. they were both gouged from crap getting inside. when i purchased bike it had no airfilter and housing so i expect that all the damage was caused from no filter. Does anybody have any suggestions. I think it could be in the carb and jetting but not sure
oh and is it true if you take restrictor out at the connection point of exhaust and cylinder that this bike would run faster (better)
thanks
Mike

 

[nickyd]

are you are using the stock intake and airbox?

 

[cope]

yes everything that I changed is stock. Now notice if I put ANYTHING infront of the intake it will bogg down. I have placed a window screen in front and even (just about 1"close) that chocked it of air.

 

[nickyd]

the mouth of the carb yolu are saying? If I do that to most bikes, they will choke...are you saying that the bike will stall completely with the intake intact? i'm wondering if you're just now realizing the small amount of power a PW50 puts out - true with free flowing air, some bikes will run better but at the cost of frying the motor.

 

[mtk]

Does it still have the exhaust restrictor in place? It will definitely run better without it.

As I understand it, all PW50s are jetted hopelessly fat from the factory, making an already weak engine even weaker. You might want to try a smaller main jet in it.

You can also disable the oil pump and run it on premix. The oil pumps seem to put in about five times as much oil as the engine needs, which turns it into a wonderful mosquito fogger but makes it run poorly. To do this, pull the oil pump, remove the plastic gear on the end of it, and reinstall the pump. On the one I did, I also removed the oil lines and tank and plugged all the oil line ports to keep dirt out of the pump and keep from screwing up the carb. I filled it with the same 32:1 premix I use in my CR250 and the little bugger ran pretty well.

 

[cope]

nickyd
thanks
yes when i put on the stock filter and housing it will stall completey. with it off it runs great but the slightest interuption of air will bogg it down.

 

[kevinacker]

Thanks for your posting. My exact problem with one of our two PW50s. Where is the restrictor plate on the exhaust, will remove it as well. Thanks. kda

 

[Patman]

Remove the pipe from the head and there will be a "washer" that is smaller than the diameter of the pipe IF there is a restrictor in place. It might stick inside the port or inside the pipe but it will be obvious if it is there.To help diagnose things maybe remove the silencer from the end of the exhaust and see if freer breathing there helps the carb restriction issue.

 

[cope]

ok. I have burned out hte exhaust in a hot campfire and poured out alot of crap. after doing this it still ran the same.I still think that this is a jeting problem within the carb itself. keep the suggestions rolling
thanks patman for the info

 

[FruDaddy]

all PW50s are jetted hopelessly fat from the factory

This is an absolute fact.

You can also disable the oil pump and run it on premix. The oil pumps seem to put in about five times as much oil as the engine needs

You can also adjust the stroke on the oil pump with a dial gauge.
Try adjusting the mixture screw and see if it helps. You could also try a less restrictive air filter. Peeweecycle.com sells them.

 

[blackbox]

Cope are you from wichtia? I have a friend from there named Cope.