I hope some of you Ski-Doo guys can help me out here.

I got a call from a friend of mine tonight who just picked up an 88 Formula Plus. I don't know
which engine it has but he said it has 2 non-standard carbs on it. Does anyone know where I can
find info for him on what was stock? I've poked around a bit tonight but haven't come up with an
answer.

Thanks in advance!

Yamaholic

The 88 plus came with a 521cc engine with 40mm carbs and was a pretty quick little sled.It got detuned and had smaller carbs in 89.

ya in 89 they went to 34s

the 88 was a giant killer with it 40s

They went to 34s because it was killing the 89 Mach 1 583

1988 Formula Plus engine Type 537 (521cc) Mikuni Vm 40-30 (MAG) and Vm 40-29 (PTO)