Okay, I used to race HS way WAY back when, and I picked up a cheap basket to relive old times. I'm going to go through the motor, but in the interim, do the later right drive IT175 and 200 engines swap into this frame relatively easy? Because I see good running cheap examples all over the place. Would be an easy way to get this thing running this summer. TIA
you're better off starting with a it200. they're dirt cheap, and the suspension, power delivery, and handling is light years ahead of the 81 it175.
on the it175 the suspension is it's biggest weak point. swap in a set of yz forks/triples and check spring rate - all it175's are spring too soft unless you weigh 145lbs - and original springs are pretty beat up after 30 years..... change rear spring for a stiffer one. rebuild rear shock while you're at it (i can't remember if it175 81 is rebuildable, the earliest ones were not. but i assume it is). also check specs on the fork tube height in the triple trees - many set them back to even with the top, when they really should be at 50mm sticking out top (might be different for 1981 - i only know the j/k models)) the motor is what it is, runs good mid/top, not bad low grunt, but nothing like the it200, so maybe figure a flywheel weight, or work on squish/porting. the it175 motor shifts better than the it200, i'll give it that for sure.
What I would really like to know is whether I can swap a later right drive 175 or 200 into my 81. How similar are the mounts?