Thanks for the reply. Had me wondering if the prior owner had mistakenly put the wrong piston in , causing the meltdown. Especialy after I just ordered $263.00 worth of parts. Also while I'm here,does anyone know what fuel pressure it would take to feed this engine. I'm guessing 1lb or less. Since the engine sets higher than the fuel tank in a kart, and after the meltdown I'm reluctant to trust a vacuum diaphram pump.Considering a low pressure mini electric. Thanks Again!

 

you should share this sheet with the top speeds....

 

I don't follow what you mean, who what when where are these top speeds?

 

if you read the first post... guess i should have quoted it

 

1973-1980 CR250 were air cooled .. 1981 was first liquid CR250 ..

 

My last post was refering to ATC250R ... The 81-84 are air cooled .. 85 was first liquid cooled ..

1973-1980 CR250 were air cooled .. 1981 was first liquid CR250 ..

 

the 81-82,83-84 both have the same stroke and bore size 64mm(stroke)x70mm(bore) but the 83-84 has a bigger carb (30mm vs 28mm)...the 85-86 have a smaller bore but bigger stroke 66mm(bore)x72mm(stroke) and the carb is bigger (34mm) than the 1st and 2nd gen 250R's ... the insides of the 81-84 motors are pretty much the same ... you get your speed difference from sprocket,carb and tire sizes...i run a stock 85 carb on my 83 with a stock pipe ,sprockets and reeds and it ran strong till i ate the piston... try "www.airfoolers.com" its a sight thats all about the air cooled R's good bunch of people there

 

the guy you bought the trike from most likely put those parts on