lost power

[datonamanmike]

i was leaving my house this morning and when i started up my motor i relized i didnt turn on the tail light so i stoped
the motor poped (kind of a backfire) and stalled
now its harder to start takes longer to get up to speed
and i feel air coming from the screws on the left side of the motor
did i blow this thing up already ???
it still runs but not as good
any help is welcome and thanks in advance
by the way 2 stroke china kit from boygofast

 

[Jemma Hawtrey]

from the description it *sounds* like a gasket problem - if by screws on the side you mean on the cylinder or the side plate on the crank.

Two strokes use the crankcase as a pressurized part of the fuel system - if pressure is lost or reduced then the engine will not run as well..

I would suggest having the head and cylinder off the motor and checking the gaskets for leaks - that will show up fairly readily.

there might also be a problem with a broken ring or circlip as well, although I find it a little strange in both cases that you would have been idling when it had this problem..

hope that helped...

Jemma xx

 

[datonamanmike]

thanks for your reply Jemma

it was more like as i slowed down to stop the motor stalled as it stalled it kinda poped (like a back fire )

guess im taking off the head and cyclinder
will i have a prob getting the rings back into the cyclinder ?? will i need a ring compresser ??
thanks
the air does seem to be coming from the side plate on the crank.

 

[Jemma Hawtrey]

thanks for your reply Jemma

it was more like as i slowed down to stop the motor stalled as it stalled it kinda poped (like a back fire )

guess im taking off the head and cyclinder
will i have a prob getting the rings back into the cyclinder ?? will i need a ring compresser ??
thanks
the air does seem to be coming from the side plate on the crank.

It does sound more like a gasket problem, if you werent gentle coming of the power you might have gotten a suck back effect that would have momentarily raised compression and popped a gasket somewhere..

As far as the rings go, it doesnt sound like that is the most likely cause, unless you have been hearing odd noises since as well as the drop in performance.. if a ring has broken or unseated and slammed into one of the ports you would definately know about it sound wise..

The fantic TI bikes used to demolish rings on a regular basis in just that way - you'd hear a nice tinkling noise and bits of ring would be spat out of the exhaust - at which point the bike wouldnt manage more than 40mph. They were only a 50cc producing 6.5hp through a 6 speed transmission making 65mph so they had excuse for being sensitive - although if you used the Iron cylinder from related bikes such as the fantic GT that would solve the problem.. apparently they were one helluva moped...

Jemma xx

 

[datonamanmike]

so should i just replace the side cover gasket or should i go ahead and do the cyclinder and head gaskets too ??

no noises like rings rattling

 

[Bikeguy Joe]

First check you head nuts for tighteness, they may just be loose.
Do you see oil or residue of oil leaking from the base or between the head/cylinder?

 

[datonamanmike]

the head bolts are tite

iv had a tiny leak from the base of the cyclinder
from day one

there is a leak in the side cover and i feel air getting out at the screws in the side cover

if i take the cyclinder off will i need a ring compresser to put back together ??

and can i make new gaskets for the cyclinder and head
or should i order some from one of our fine venders ??
thanks

 

[Joshua]

I've had a small oil leak from the lower gasket from day one too. I've been curious if I needed to pull the head and make a new gasket but it seems like it isn't causing a problem. but I know it probably will some day. how hard is it to get it all back together after replacing the lower gasket. oh and my bolts are tight.

 

[misteright1_99]

You wont need a ring compressor, but just note the small alignment pins in the piston ring slots, where the ends of the piston fit...You should get or make new gaskets and not use the old ones, at least for the base gasket, too much work if it doesnt reseal correctly.

 

[Venice Motor Bikes]

If you're feeling air from the side cover screws... you might have blown a seal on the side of the crankshaft?

 

[Norman]

I agree if its leaking out of a side cover take the cover off and see if the seal is leaking which can really raise jell with the engine. somewhere on here I've posted the seal sizes you can't repair a leaking seal but you can replace a leaking seal.

 

[datonamanmike]

I agree if its leaking out of a side cover take the cover off and see if the seal is leaking which can really raise jell with the engine. somewhere on here I've posted the seal sizes you can't repair a leaking seal but you can replace a leaking seal.

where can i buy this seal ???
is it real hard to replace ???
i think this is the prob

 

[datonamanmike]

got my new crankshaft seal yesterday
installed it and it seems fine now
no more air getting out on the chain side

i think i need a new plug little sputtering
going on as it warms up

thanks venice boy you were spot on

 

[Bikeguy Joe]

Thanks for the update and resolution of the problem.