The front tire tubes has a molded rubber core inside the tube.
Is this flat free with some air. There is a valve stem on tube GTM4-5 is on tube. Can't find on internet. Will regular tube hold up?
http://www.allwalkerparts.com/product-p/4968.htm
View attachment 352795

http://www.allwalkerparts.com/product-p/4968.htm
View attachment 352795