What prop should I be useing ???? 19 or 21

[Grew 194]

I have a grew 194 with merc 165 and pre alpha 1 leg I know this maybe off the wall:facepalm: but I have 2 props and want the best performace one for my boat so is it the 19 or the 21. thanks for your help

 

[steelespike]

Re: What prop should I be useing ???? 19 or 21

If you read the stickys at the top of the page it will help you understand prop selrection better.
Your best prop would depend on your typical load and activities,and whether you try for most top speed or low to mid range performance.The motor needs to operate near the top of its wide open throttle rpm.rating.(4300)Very basically the 19 should give better hole shot with slightly better low to mid range control.The 21 could have slower hole shot but better top end.
This is assuming the props are similar material manufacturer and design.
The best way is to test both and get us the info in the stickys.