K,


we picked up a 2001 yamaha blaster 200cc today,


With known issues. cylinder and head off, was blown engine, piston shot.


So, Know I need to have it bored out and new piston and rings.


I dont have a manual yet, just ordered one.


But My question is, when looking at the rod. it looked fine, but had side to side play.

I did not use a feeler gauge or mic it . but was wondering if anyone new the tolerance or if this is common.

I have dealt more with 4 stroke than 2 stroke engines. and I felt the side to side play was best guess around .15 to.20 thousands, again until I actually get a reading. best guess.


So, does anyone know the min and max, side to side play on the rod / crankshaft. ?

Its like in totally really nice shape, exsept for the engine issue. story goes, 19 year old kid bought it new 2001. had it les than 1 year, was out playing in the snow with it and it locked up,. it sat for about 2 years, then was sold to the guy I bought it from today, was was gonna fix it, but never got around to it.

The head, looks so darn clean, when I removed it off the cylinder, no pits, no build up, just nice overall.

So the guy said, that the likely issue was not rejetting it for winter riding. I find this hard to believe, Any one heard of this before ?


I know my old 2cycle snowmobile, I drove that in winter and for kicks around the yard in the summer.


I was thinking, either he was out doing do-nuts and over reved and over spun the engine and it locked up.

Thats my take, unless anyone has heard of a blaster, having to have jets changed for winter riding ??

Or to cold, the oil flowed slower.

The crank turns nice and smooth and clean, no slop, Just seems like some slop , side to side on the rod to the crank, but it rotates and flows really smooth.



Thanks

 

I'm not sure what the side to side tolarances are, but usually some side-to-side play is OK, it's the up and down play that should be tight.

Colder weather will lean an engine out more, so you have to be more careful when riding when it's cold, don't over-rev the engine for long periods. Here in NC the weather can go from 100 degrees in summer down to 10 degrees in winter, and I (or anybody that I ride with) never re-jetted for temperature or had a problem with jetting, but on colder night rides I would notice the exhaust pipe will glow red at the engine, a sign of a lean-running engine. When you get it running, just don't be as hard on it in the winter as you would in the summertime!