My port engine sounds just like a blown engine, but I dont have a blower!

You know, it sounds like one cycle is lower than the other...

It only does this after a good run...

Any ideas?

Nick the only option I see is to slap a blower on it and call it good

You guys are a big help!

NOT!

now BEAT IT!

Timming chain mabe?.. distributor bearing? vacuum advance springs

all three of those things sound expensive...

The fun never stops for you does it. Look to see if there is something by the air intakes that would make it sound funny. Maybe a loose hose or something. Try spraying some carb cleaner or brake cleaner on the belts when it is running. if the sound goes away for a minute, tighten or change the belts. Is it running fine other wise

Insure it and sink it. Oh wait you already thought of that.

Assuming these are not efi motors, how about a partially sinking float?

Its all about ball bearings

Nick if that things sounds like a gear driven blower I would definetly check a timing chain. One of the last things you want to go on you.