1977 Yamaha GS340 Info wanted

. Someone Just gave me a 1977 Yamaha GS340 Snowmobile.
IT had not run for Fourteen Years. I had it running in 1 hour
And runs great. And looks Mint. My questions Is there any place to Find Info like the Specifications on these Sleds
what to look out for .
the top Speed . Where they Dependable?
Thanks. For any Help

Watch out for dried up crank shaft seals .Sitting that long they could be leaking this would cause a lean condition . This would show up as a high idle. Or white spark plugs .

Thanks for the info