yfz rebuild

[hondadude101]

ok, so i have been having this problem with my yfz since i accidentally ran it out of antifreeze, i thought it was wiring but i took it to a guy and he asked around to a few people about the motor since it would turn over by hand some and sometimes it catches, he thought it might be the needle bearing on the bottom of the rod, i do not know if it has the oil mod done, does this make since to anyone? I guess the only thing i can do is tear it apart and see, but does this sound right? Also i was told it has a hotrod crank in it and that they are rebuildable, if it comes to that does anyone know where i can get a rebuild kit for it? i couldnt seem to find anything on that. the bike is an 05 model

[maxamillion]

its possible the crank bearing is out like you said. there may be cylinder/piston scoring since it was ran without coolant. the top end will definately need disassembled and inspected.

in order to tell if the oil mod has been done, take the oil filter out and look at the housing behind it. if the mod has been done there will be a hole drilled in the housing.

the hotrods crank is rebuildable. you can get parts for it on their website just google search hot rods cranks. it will come with a new rod, pin, and bearing. it may be more cost effective to just replace the crank by the time you have a shop rebuild the one you have. -Max

[hondadude101]

yes the cylinder has scoring on it, i was planning on replacing that and maybe stroking it 1.4mm to make it the 449cc, I was just wanting to see if this sounds liable before i tear the engine apart

[hondadude101]

does anyone know if the newer OEM cranks will fit in the 05 motor? if not what is the best way to go there? hot rod? wiseco? OEM?

[squadie]

The 06+ crank will give you a 449cc versus the 439cc of the 04/05. I've got the 06+ crank in my 05. I think a new piston is required too as I'm pretty sure the wrist pin in the 06+ is a larger diameter than the 04/05.