Tick

Tanks a lot, i really appreciate your help! I still havent received my cilinder from the local company so i decided to try to fit TDR cylinder. How will i see if it fits or not? Will be the resault seen after the first engine start? What is the worse thing that can happen? Thanks.

I really need piston to the next friday. I dont know where should i buy it. Does anyone know one good online shop where i could buy piston (doesnt mater what kind just that it will fit) and that they have it on stock so the piston could be deliver to the next friday. Thanks. Tick

Thanks a lot. I have to buy new piston. What are the differences between cast pistons and forged pistons? Forged are better right? And their size is up to 61mm. Mitaka size is max 58.4mm. What are the differences between mitaka, prox and vertex pistons? Tick

Ok, now i find out why has this happened. It is not because of too small main jet. Well may be also because if this. But the main cause is, i think, about 2mm deep groove inside of cylinder made by axle which hold together piston and conrod. This ting went out of its normal position go to the right side and it was rubbing against cylinder. But i am very confused because this axle is not damaged at all. i cant believe that i was driving with so much damage on cylinder for about 200km per day. I also dont know why is so big hole on the top on cylinder and why is spark plug completly destroyed and why are scratches all around the cylinder. I hope i will get answers because i am really confused and sad because of all that shit which is going on whit my yamaha for about 1 month now. All i want is to ride my bike safely without worries that it will brake down again. I dont know if i will be able to trust my bike again and if i will have enough courage to drive with full throttle. Thanks for help.

My motor was running great until it broke down. I suppose it brakes down because it has sport exhaust system (gianelli) and sport air filter but the main yet was the same. There was not enough petrol and oil and i think that it stopped working because of that. Do you have any idea what could went wrong? Here are some photos (sorry for bad quality, i dont have digital camera so i take pictures with my mobile phone): I dont have cylinder at home at the moment so i couldnt take a photo of it. Thanks, Tick.

I opend my engine today and my old piston is on the top completely black. What colour should it be? Silver? And cylinder has a lot of scratches but i cant feel it. So i dont know if it needs to be repaired.

Well, dont attack me, i just wrote what i had heard. So you think that mitaka is good quality. Yes, I can take it back and get a refund, but i will have to take back piston kit as well (i bought it with cylinder fo 100€). So you think i should buy mitaka piston and repair original cylinder? Tick

Ok, thanks. Yes, this cylinder has nickasil, so it has to be removed and replaced with new layer of nickasil. For this piston i heard that they are really low quality and that i should buy org piston or (better) vertex piston. Tnx

i am not sure if everyone independent motorcycle shop can repair my cylinder, actually i know just this guy (who repairs it for 140€). Well, I am very cynical about this repairing for 35€. What is cylinder re-sleeving? That costs around 130€. Actualy i will probably sell the TDR cylinder and piston back to previous owner. He said that if i dont want it anymore he will buy it back It is cheaper for me to buy a new piston kit. What is the difference between this piston kit here which cost just 70€ (http://www.pjme.co.uk/acatalog/Yamaha_DT125R_Engine_Parts_Top_End.html#a400) and between original yamaha piston. I buy original yamaha piston kit and gasket set for 140€ including shipping costs about one month ago. This piston kit is much cheaper i think. Tick

Thanks a lot, i understand everything . Repaired costs for cylinder are around 140€, and he said if you can feel any scratch it has to be repaired. Probably i will drive to official service for yamaha and ask there, but i think it must fit. At the moment i don't have a lot of money for repaired costs on official service because they are pretty expensive. I think i could put it together by myself but i don't think i have enough courage to do that . I have never do that, i was just once watching, when my friend replaced old piston with new one. Tick

Well, forst of all thanks for answer. I come from Slovenia and last year i bought used yamaha DT125X 2006. It has gianelli and sport air filter. But i didn't know that the main yet is still the same as in original carburator so after few thousand kilometers it brake down (i dont know what is the world in English, but i think you know what i mean). Piston is completly damaged (it has a hole on the top) and the cylinder is also damaged. Oh, my mistake, my cylinder has 3MB00 part number. It is damaged and it was already once restore. But i had good opportunity and i bought almost new piston with new rings and cylinder (it has to be re-bore) from TDR 1998 for 100€. Now i want to put this parts in my DTX. I don't know how badly is may cylinder damaged but i don't know if it can be re-bore again. Well, maybe it could be because my friend who helped me to make my motor work again temporarily (i am not an expert in this things, i just have basic knowledge) put in my motor the first piston (when my motor broke down there was the second piston in it whit just 1000km) and damaged cylinder but the motor has little compression. Thanks. (P.S. Sorry for my bad english)

I would ask something here if you don't mind. I have damaged cylinder on my yamaha DT125x 2006 and now i bought an used cylinder of yamaha TDR. On my cilinder on right side is written 4MB00 but on bought cylinder is written 4FU00. What are the differences? What does this numbers mean? Can i put cylinder of TDR125 on my DT? Thank you.