Udi rc arrow 5 bad prop?

[Rcjmazz21]

Hi all so I picked up an arrow 5 udi rc boat. Tested it once with the prop it came with and it ran great. Tried it the second day with An eBay prop 35mm x 1.4mm and it wouldn’t even move at full speed just spun the prop. I’m confused as to why?

 

[tntpoof]

was prop slipping on flexshaft?. did new prop not have keyway?

 

[Rcjmazz21]

was prop slipping on flexshaft?. did new prop not have keyway?

The pitch of the prop was to low. Worked great once I put the stock prop on.

 

[tntpoof]

if you have a hair dryer and some skill you can make a jig from a piece of wood and heat bad props up an re-pitch them have a glass of water close to cool down..