Spacer Plate Question ? Help me

[250R4EVR]

Ive got two motors, one is an 89 duncan 265 and i just picked up another motor witch is a stock 85 ATC motor, i bought it for a backup. I just bought a bigbore cylinder for it, and i was wondering what pistons can go in it as far as in 86,7,8,9. Just in general what needs to be done, im looking for is much Hp as possible

Do i need a spacer Plate, do i not need a spacer plate. What year piston ? someone help me out. Thanks Evan

[Wicksbusa]

86 piston no plate

[250R4EVR]

Ok thats what i thought.

spacer plate

87,88,89 rod
85,86 atc 86 trx piston

the 87,88,89 have a longer rod, and the piston has a higher pin height.

the 85,86 atc and 86 trx have shorter rod and lower pin height.

[250R_4_ever]

Originally posted by 250R4EVR
Ok thats what i thought.

That's right