Modern Vespa

Hi first time on here so be gentle with me,

I have a problem with my ET4 the rear tyre keeps going flat when I'm riding it, I've been to the garage and had the tyre and rim checked for leaks and nothing, I live about 15 miles away from city and by the time I'm about 3-4 miles in its completely flat and impossible to ride safely!

Any ideas?

Thank you!

Replace the valves. The stems could be porous. (Is that the right word?)

First of all, clean everything up. The rim, tire and all that mess. Like squeaky clean so you can see if there is any defects or problems.

Then, inflate the tire to 30-40psi and spray some soapy water on the bead, rim and valve stem.

Look for bubbles. Rotate the rim and tire as necessary.

Find the culprit and replace as necessary.

I'm gonna put my money on a valve stem or a dirty rim not allowing the bead to seat.

-g

ESPECIALLY the valve stem and the pin inside. I've had two incidents exactly as you described and each time it was a poorly seated / defective valve stem assembly.

Oh, BTW, shalom and welcome from Israel!

also could be the valve stem needle inside is loose and just needs a little tightening.

Aloha and welcome to the forum from Hawaii. What the guys said and when your get it fixed throw some Ride On in there. I and the rest of the gang over here use it in all our tires. Good luck

Welcome to MV from the Great White North!

Sounsd like the gang has you covered.

Given the age of your bike, it could be that the rim has corroded to the point it won't bead anymore. In which case, you have to either get a new rim or put a tube in, which is good until it goes flat, because they do that fast.
What's been said so far is good advice. Clean the rim and tire where they meet. You can then coat the bead area of the tire with a light coating of dish soap and Inflate it to 50-60 lbs to seat the bead, make sure the bead is seated evenly around the tire, make sure the valve is tight in the stem, and then spray it down with soapy water. You will find out where the leak is. If you don't, spray the rim down too, and look for air bubbles. It's rare, but I've seen rims break down to the point air was leaking through them.

I don't really have any better advice than what's been given, but