Hi! My family has a 1976 X-18 that we got last summer. It's a great ride and a neat addition to what we already had (Sweet 16).
Problem #1:

About two days ago the throttle/shifter started to become "finicky" and every once in a while it would get stuck in neutral and just rev before clicking into gear. It wasn't major and it didn't slow us down from using it heavily skiing and running it hard, it would only happen a few times. But today when coming off plane at the gas dock it wouldn't shift into neutral and suddenly made a grinding noise and being stuck in forward gear. The Sixteen pulled it in and we put it on the trailer this afternoon. Could it be something to do with the gearing or something else?

Problem #2 (about the same boat):

The boat just came back from the shop exactly a week ago as it got a new MSD distributor put in. It was running great except that you had to be gentle with the throttle when getting on plane, it wasn't running normally as you had to slowly give it gas or else the boat would backfire, probably through the carburetor. This would make it especially hard when skiing behind the boat because it got out of the whole EXTREMELY slowly. Once on plane though it had no effect with performance from than on and didn't lack any top end speed. This is somewhat of an issue because last year (our first summer with this boat) the boat pretty much leaped out of the whole and still had plenty of top end.

Thanks so much in advance! Any ideas as to what these two issues could be are appreciated!
Jamie

Also: The engine is a 1990 Chevy 350 w/ 270 or so HP

Lake Champlain, VT