Fury Expert almost Extreme YS80ST to YS90

[Bruce H]

Hello guys and gals,
I have a Fury with a YS 80ST in it and it is set up with 8.45 to 1 gears. I am considering installing a YS 90 in it and am wondering if I can use the same mounts and gear ratio with the YS 90?

The 80 is doing fine and has plenty of power it's just the want for more POWER and is really not necessary for my level of flying but if it will be just a drop in then I might consider doing it.

Also, what is the ideal head-speed for these setups both the YS 80 and YS 90 with the 8.45 to 1 ratio? I have been running 1750 head speed on the 80 and that should put the engine rpm at 14,787rpm. Does this sound correct?

Thanks in advance for any input,
Bruce

[DavidH]

Yes you can use 8.45 with the YS 91. The motors should swap out with no changes.
The cases on the YS 80 and YS 91 are the same foot print. Yes you can run the YS 91 mid 14K rpms' to mid 15K rpms.

David

[Bruce H]

Thank you David.

Bruce

[G MAN]

I'm running my YS 80 with 8.18 ratio and 1950 headspeed and works good. I was running it with 8.45 and 1850 which worked good also.DOUG

[WayneBrown]

I've gotten a few mods worked out for the 80's that mimic the power of the 91's, and some mods for the 91's that make them run like an scalded dog..
A few more trials and I might have to do 'em for money.. :)