Modern Vespa

I have a 74 rally 200 and it has started making a high pitch squeel at low speeds. once I open it up and get moving I cant hear it anymore. any reason why it might do that?

There are a number of places a squeal can come from - easiest is maybe the flywheel rubbing on the fan shroud. Where is the noise coming from? Does it increase with revs? Decrease? stay the same? Is it the same in all the gears?

An airleak at the head can cause a very high-pitched squeal.

it is coming from engine area. it increases with revs,but can still hear it a little when at idle. it sounds kinda like the squeel sound a car makes when it has a loose fan belt. Know what I mean?

Probably a crank bearing going out

would that be the easiest thing to start with? I've never wrenched on it before nor do I really know how also what would be a good reference other then this web site like a book?

Easiest thing is to check your head is leaking air. If your head is warped or if one of the bolts is loose it will leak and cause a high-pitched squeal very similar to a worn fan belt in a car. It is much easier to remove and inspect the head and cylinder than to replace the crank-bearing, which requires opening the engine cases.

maybe she is just happy to see you? happens to me all the time...

i hope so! I'm looking up some books right now. I was able to find a owners manual on scooterhelp.com and another reference they had was the Haines manual I'm gonna check out. so i can find all the parts on it. It seems to be running great other then the noise. to tell ya the truth im a little xcited ( and nervous) to try to figure things out on it for the first time.

To test for the head leak without having to do much:

Remove the cowl cover, exposing the head. Start the scooter. Get some good carb cleaner in a spray bottle with the nozzle attached. Where the head meets the cylinder? Spray carb cleaner there while the motor is running - if it revs higher on its own (or even bogs out and dies completely) then there is your leak.

Dare I ask if there is oil in the cases?

+1 i dare

so, yes there was oil in the gear box. now my question is what kind of oil should I use? the manual says SAE 30 (+) is this the best to use? and I am going to get the carb cleaner to check for leaks. Thanks for all of everybody's help!

SAE 30

Not 10 w30, not 5 w30, just plain old 30.

Non-detergent (check for that)

Not synthetic.

Plain old 30 dinosaur oil.

WOW!!!!! I think that worked I changed the oil (which was filthy!). might I add that is a hell of a small hole to get the oil in. I used the SAE 30 from the local auto store and sprayed the carb cleaner where carb meets head and no leak. so I think maybe it was just dirty old oil? anyhow its not making the noise any more so thank you. maybe it will come back it is still there a little but not as apparent. Thanks again for all your help.