Modern Vespa

My MP3 400 loses air in the front tires. I purchased the scooter new 600 milies ago (about a month) and have had significant loss of air pressure in both tires (i.e. air pressure readings of 5 -10 PSI). The leak(s?) are slow at first but, apparently, when the air pressure falls to a certain level, the pressure loss accelerates. I told the mechanic abount the problem when I had the bike serviced at the 600 mile interval. The mechanic said he could find no leaks or other issues with the front tires. Has anyone else experienced such losses of tire air pressure and, if so, what was the fix??

Use the soap/bubble test for the whole tire, including the valve stem -- which is often over-looked.
Good luck!

After running through the winter, my mechanic found rust between the tire rim and the tire which was allowing a slow air leak. FIx was clean/polish/tire grease and has to be redone occasionally due to salt corrosion...

You shouldn't have any corrosion between the tyre and rim, it is a powder coated suface just like the rest of the wheel. And is not something you should have treat repeatedly. Demand a new set of wheels under warranty, if the shop you bought it from is not helping try a different dealer.

I recently had a similar issue, but mine was due to the shop scratching through the coating whilst fitting new tyres, after complaining they came good and supplied me with 2 brand new wheels

Next, they were promptly installed on the rear of your MP3 along with the invisible Tow Pac kit.

ay.

when i first got mine my right front leaked a bit. very slow like you described. they couldn't find the leak so they just took off the tire, cleaned everything up and remounted it...problem solved

I hada front tire leak took it in they said it was a bar code paper on the the tire that was causing the leak , it was just enough of a gap to cause the leak.

Check valve stem valves first, make sure they are tight. Then have them remount tires and clean both surfaces really good if nothing is wrong with the valve stem.

Thanks for the suggestions. It helps to know that others have dealt with the same problem. I am going to take my MP3 back to the dealership and have them take off the tires and clean the rims, replace the stems and remount the tires. I should have had the dealer do that in the day I bought the scooter as I noticed the tires were low (almost completely flat) on the dealership floor. Live and learn. I love riding my MP3 and I hope I can get this tire issue resolved with a lot of hassle.

have you used a spray bottle of soap and water to try and determine where your leaking at yet?