question about power. HELP!

[harrismblax]

iv got a question. non model specific.

i have a 125, and i just changed out my rear tire from a wayyy worn down 100/90 maxxis to a 120/90 dunlop something..

now my bike bogs easier, and it feels like im losing power. is this because of the tire, or does my top end need to be rebuilt, or what?

how much would it cost to get the top end rebuilt?

[jo-hn1777]

i did it myself for about $60! but i got a really good deal on a piston kit from fleabay id say if you do it yourself it should be around $100

[lilyamaharacer9]

iv got a question. non model specific.

i have a 125, and i just changed out my rear tire from a wayyy worn down 100/90 maxxis to a 120/90 dunlop something..

now my bike bogs easier, and it feels like im losing power. is this because of the tire, or does my top end need to be rebuilt, or what?

how much would it cost to get the top end rebuilt?

A top end on a 125 can be done for around 100-120 with gaskets. And its because of the tire that your losing all of your power, even youll notice a 450 not run as strong with such a wide tire, you need to go back down to a 100/90.A 110 even will rob a good bit on a 125.

[Justin 314]

The wider tire is robbing power. Somewhat OT, but o-ring chains do it as well.

[Slinkyman16]

where in cali are u from.. buy the parts.. can have the pistion swapped, and motor runnin in a hour...

[jjesneck]

The bigger new tire = more rubber = less power. The new larger tire weighs more than the old one, and takes more power from the engine to rotate it. That 120 tire is a 250/450 tire. The new tire is also getting much more traction which is also making the bike act differently, compared to a "wayyy worn down" tire.

[harrismblax]

okay, so im spot on then. my friend gave me this tire, and its already a little used, so i figured i would try it out. i have a D.I.D. O-ring chain as well. i leave for college in a couple days anyways, and so my bike will be in the shed till winter, and i think ill be getting new tires and some other stuff when i come back. if i can budget my savings well enough. wheelset and clutch are also on the list.

how can i tell when its time to rebuild the top end? does it start getting harder to start? or anything of that sort?

i live in a little town called mendocino, in mendocino county. its west of ukiah, and about 3 hours away from SF and the bay area. world class singletrack riding around here. we have thousands of acres of redwood forrest to ride in. and hundreds of miles of trails connected by old logging roads to ride. its a pretty great place.