i have a .91 on a yak 54 with a 14-8 prop but it comes in fast at landing what size prop do i need to run

Get the idle as low as you can, it will help some. I am running a 15X4 prop on my .91 Fs.


Buzz.

do you think that will slow it up or do i need a smaller prop thanks

Bigger diameter, smaller pitch. That will slow down your model on landing, but will also reduce your top speed. If you don't want to reduce the top end, practice slowing it down at altitude. If you can get it to descend at idle just above stall then you can slow it for landing, and you just need more practice on that plane. If it just cruzes around at idle not descending then your only good option is to change the prop.

thanks for all your help the plane flys ok but a bit up and down but it looks like it is flying on the most part good some guy where i fly said to move the cg up a 1/2 from what the book as said what is your cg

Moving the CG can improve the flight characteristics, but if it is moved too much it can cause catastrophe. I would recommend getting some help from someone with a lot of experience with aerobatic flying.

ok i will thanks again

2 stroke or 4? If it's a 2 stroke a 15x4W from APC is a good choice.

CG location is mostly a matter of personal taste, as some like it a bit nose heavy while most hot shot pilots prefer a more rearward CG position. Fly the model with help and experiment with the CG positioning until you are happy with how the model flies.

Karol