why is this my new problem

[rea]

In 3 days i have seized my R twice yes folks thats right TWICE.The last time it idled for about 5 min went done the road slow and easy and she bound up.I tore it all apart and it must have got real hot cause it melted the piston.Im only baffled because it showed no signs of running lean.Ive heard that if coolant gets in the cylinder it will seize could this be my problem I mean if its getting hot enough to start to melt the piston something's not good but its only the sides not the top.When i took the jug off the rings were even in there proper place the piston was just melted the length of it in about 4 places.All i know is 2 separate jugs and 2 separate pistons==same all of a sudden problem

you must have a cooling problem, be sure to use new gaskets everytime, and use the proper torquing specs on the base gasket and head gasket

[86 Quad R]

as stated, it sounds like a cooling issue for it to melt down that fast. i would start by inspecting the cooling system.

[C-LEIGH RACING]

Check this,
The radiator fluews inside for coolant flow & the outside in between the fluews for dirt or silt blocking air flow.
Water pump, the impellar can get loose & wear the end off & not pump coolant.
Cylinder bore to piston being too tight after a bore job can cause a 4 corner seize.
Old stail gas,
Water or trash in tank,
Gas tank cap vent or hose stopped up, dirt dobber bees love a little hole to build a home in.

Now this is crazy but it can happen, the drain hole in the bottom of the steering stem can get stopped up, fill with water & mud & trash & then you stick the gas cap vent tube in the stem & the gunk is sucked back into the tank, then where does that crap go, right to the bottom of the carb bowl to be sucked up by the main jet.

Neil

[rea]

Thanx for the help.I think it was a couple of things I noticed that my radiator cap wasnt sealing proper and the head gasket as well so cleaned up the cap and got some copper spray and so far so good.All thou im still being gentle.Now that its running better the other cylinder i have is ported it came with the quad in a box of parts now i need some bigger jets its at 55pilot 175 main and still a little lean I assume thats normal for a ported cylinder but am not sure

[fireburns99]

with my ported cylinder i'm running a 180 main, and a 60 pilot, with 170 lbs of compression. So it sounds like you're pretty close.