Hmmm...only the lid should hit the frame. I rocked a P200 engine in my rally for years without issue...but i just had your average metal lid on the carb box...like, for a super or sprint or vbb or something.
Other than that, it should fit in there fine.
*edit* wait...i remember that it was hard to get the engine swung into place if you put the front swingarm bolt in, and then tried to pivot up the back end - the carb box would block this. I typically had to kinda lower the frame down on top of the engine, and attach both bolts at the same time, rather than swinging it into place.
Some of the travel of the engine is thus limited by the frame... it never was a problem for me, besides rubbing away a bit of paint right on the inside lip of the frame where the carb box meets it.
⚠️ Last edited by Rover Eric on UTC; edited 2 times