21cc weedeater motor help

[trs]

Hello everybody, I need some help with a few things. I have a 21cc "Weedeater" brand motor that I matched (fabricated) up with a 40" Prather Deep Vee hule. It runs and handles suprisingly well considering I really did't know what I was doing when I started the project. The problem is I guessed when it came to the prop? I have tried a Octura X665 (bronze) and a Prather 275 (ss). Are these too big?? Also, I am trying to get a little more performance out of this engine. Can this be done with a different carb? Is there a pipe that will work with this or do I have to custom fab one (being that it being held by spring tension)? Any help would be greatly appreciated!

[Doubledog]

Uh Oh... We've got a fabricator amongst us.:D Cool, might need some ideas from you later.

Never turn down a chance to try a different prop.:)

Without seeing anything its a guess. What engine?
21cc & a 75mm prop seem too big. the Octura X665 (65mm) might be ok. Which prop is moving it the fastest? My guess would be the smaller. Is it surface drive? That can play a little with props too. What size shaft? 1/4 or 3/16.

Other than that, a 'guess' suggestion would be to look at either a Prather 260, 265 , octura X460, x465. They're basic 3/16" props that you can get used for around $10 unworked.

Talk about shooting from the hip:D