Bought a bike from someone who said they just put a new wiseco piston and rings in. I broke it in very easily and ran fine for a few rides but did sound a little tingy. I've never had a smaller bike, always 500cc bikes. Now it won't go 50 ft before it bogs out as if running out of fuel. Black oil comes out of pipe and I pulled off cover just above where pipe comes out of cylinder(power valve-not sure what it's called) and lots of blackish(seems too thick and dark to be just fuel) came out of there also. Saw scarring on piston when I looked through the exhaust port. Did I break it into quickly? Was I lied to and the piston was never replaced? Is there some kind of seal that could have went bad letting transmission oil into cylinder? Can I take some kind of compression test to determine if it's the rings before I take it apart?

Wiseco motorcycle piston ring end gap

if its a 4 stroke then the timing sproket cudda loosend and piston bent the valves--send issue to [email protected] hes a master

Yes, the problem is linked to compression getting past the rings. The pressure goes to the gearbox then some oil gets carried out of the box along with the compression. Too much oil in the gearbox makes the problem even worse. You shouldn't need pistons. Chances are the rings are just stuck in the piston ring grooves. Sometimes they can be freed up by the mechanic manipulating them. Often they break when manipulated. It all depends on how badly they are stuck. If a piston is badly scored it needs to be replaced. The scoring can stop the rings from sealing the cylinder. Do this; drain the oil then fill the box to the proper level. Wash the bike to rid it of previous oil spills. Now see if the problem returns after the washing. If the rings are stuck , the bike should be smoking as you start and ride it. Chances are that only the rings will need to be replaced. Any chance you can be there as the mechanic takes the cylinder off? A dishonest shop could bring you a badly scored piston and rings and say they came from your bike when in reality they came from another bike. They free up your rings and charge for new pistons and new rings as if they actually put them in.

Yes. You need a new top end. Being very hard to start, and having no power, sounds like you have no compression left. You need a new Piston Kit. Wiseco make one for your model.
This is a very high reving little bike, the piston and rings in them dont last very long.

you probably have time 180 degrees out....4 steps....(1)piston top dead center...(2) camshaft aligned with marks...(3) dist set for #1 cyl to fire ...and (4) timing marks on damper pulley aligned with marker on the cover or eng block...good luck

hi, will the shift lever shift up when the bike is being pushed along, is it stuck in neutral, if its in neutral then push it down make sure it goes into 1st gear then can u get someone to push u whilst holding the clutch in then release the clutch and see if you can jump start the bike that way.

when you push the kick start down is it turning the engine over properly and if so if the compression is really to low then the chances are the piston ring has broke and scored the side of the cylinder if this is the case then you need to get new piston and rings and a new cylinder.

The problem with moto x bikes is they are high power and work at really high temp so parts need changing more often the piston rings need changing every 25 to 35 hours of riding time you need to do this as they ware and brake if used any longer.

you also need to make sure you get the petrol and oil mixture spot on as if its not getting enough oil it will blow the piston and rings so you need to measure exactly the correct mixture.

these bike are expensive to maintain and need new parts on a regular basis so remember this the next time you get the bike running

yea, for most bikes they only come in .020 increments now. if your looking to freshen up the top end, then youll have to go to a 56.00mm piston. there will be almost no change in displacement or jetting from 55 to 56mm. if your replacing the piston, its best to have your cylinder bored anyways. since the worn cylinder walls may have adverse effects on the new piston rings, and they may wear a bit prematurely. a bore only costs about 30-40 bucks most places, and its cheap insurance. plus you will have the peace of mind knowing that your bore is matched specifically for your piston. I would definitely recommend a fresh bore.

take off the 4 bolts on the head after you unplug the spark plug. then take out the c clips that are on the side of the piston where it connects to the crank oh ya if the cylinder wall is scarred then you will need to repair or replace it, but if not then keep following after you take out the clips the piston should come off im assuming you bought a rebuild kit now take the new piston and place the ring(s) on it then put the piston on the rod then slide the shaft inside the piston then put the new c clips on each side then place the cylinder on top of the piston (you will have to clamp the rings together with a special tool but if you dont have it your fingers will work fine then after you get the cylinder on you can put the bolts back in place then the spark plug wire and remember to break in the new top end by driving in first gear for a few hours.

Pull the carburetor and clean it for staters.Be sure to change oil any little bit of moisture in the crankcase will let it smoke white by seeping by the valves and piston rings.Also put a little small amount of dry gas in the gas tank to rid all of the water that may have been left in the tank. I some of this will help you.

well i had the same problem with my old ttr 90 it smoked realy bad so i took off the top end an looked at the piston rings an they were fried so i bought a new piston rebuild kit an put it in an changed the oil an it ran like a champ an didnt smoke so thats what i think ur problem is