what prop is best to use on a 91fx on a razor yak.i have 3 apc props from a 14x4x,15x4w,and a 16x4w,test flew it with a 15x4w and it was pretty good,need a bigger tank than what comes with the arf as it only gives 3 to 4 min af flight time.was gonna try the 16x4w but figured i would ask as i think it might be too big for the engine i know the 14x4w will work

Stick with the 15X4W that you have.

thanks,the 15x4 works better than the 14x4.

anyone take the cone baffle out of the stock muffler on their 91fx?thinking on taking it out of mine but am unsure if it will hurt the engine

Yes, you can take the baffle out. I'm not really sure it makes much difference though. I've run the engine both ways. And yes, the 15-4W is the best prop for the 91FX.

what are you guys using in the fuse where the bolts that hold the engine on to keep the washers from crushing the wood?

I use the tetherite engine offset plates we sell. Made of the same glass filled nylon the gear is made of. I cut 3/8" wide pieces with my band saw and put these on both the engine side and left side under the nylon-insert lock nut.

go to your local hardware store and pick up some fender washers that fits your bolts. They are bigger, therefore spreading the load over a larger area. You may have to trim the washers if they interfere with the bottom of the engine, if it stick out past the fuse. No big deal, hold 'em with some pliers and cut off with a Dremel cutoff tool.

just ordered a 15x4 xoar prop for the 91 now will this prop be like the 13x4 i got for the 55ax,with the 55 spool up is by far faster and it pulls way harder than it did with the apc,i figured with one on the 91fx with faster spool up it will aid in the hovering as it does not soppl up that fast and i have it running perfect

why is this engine such a slug i am running a 15x4w and it seems like it has no pull out power gonna try a 14x4 as the 15x4 seems to be to large for this engine any suggestions would be appreciated

anyone run a 4s plug in a 2s,what are the advantages in doing it

Might be worth asking that question in the engine forums. Personally I pretty mush stick with the OS8, K&B or whatever my LHS tells me to buy! LOL

i am looking at getting a macs one piece muffler for my 91.can someone tell me what one i need to get as i do not want a tuned pipe is it the one tower has for $62

http://www3.towerhobbies.com/cgi-bin...?&I=LXNUP4&P=Z