Stratus Trouble

[balsapro]

well if finally got my stratus up and running but i am having some vibration problems. here is my setup

OS 91 SZ cline mod
SB 18
611/9256 gyro with stepdown
9155 x 3
multigov
duralite reg and bat running 6 volt


so here is the problem everything is smooth until takeoff. a storm develops in the main tank and it starts to foam and continues much more at high rpm. I'm running the Maryland machine fan and the runnout was .002 if i remember correctly. Althought i know its high freq vibs could this just be due to a new engine breaking in??

I did the alignment adjustment to the motor in hover and this helped but did not cure the foam problem.

secondly the 611 its not really drifting, I would describe it as more of a hunting. I lowered the gain and no difference so i returned it back to where i had it previously.(611 display reads 36) it does not do it all the time. it acts good when the main tank is about half full, i reckon it may be due to the motor tunning but as it is it not sloppy rich.


one interesting thing i did notice is that there was not much back pressure from the OS 91 SZ and it acted like it was going lean at the end of the tank. on all my other helis,also setup with OS 91 SZ with cline after a good run you can relase the pressure and hear a psssss. so i think my tank may be leaking but i do not see or hear anything excessive.

any ideas.

[conrod]

Tail blades balanced?

[WillJames]

There is a problem with your motor/Cline setup if you do not have pressure you release when you finish the flight. Are you running a magnet?

Out of balance fan can cause just what you are describing,a s can a bent clutch stack. Do you see much clutch liner dust on the machine? Do the spacers between the bottom plate and the gear struts look good or do they look like they are melting?

[balsapro]

yes, I am running the fuel magnet. I don't think I see any clutch dust. plenty of oil though, some has a blackness to it but overall not bad. i ran about 5 tanks through it today in hover hoping things would just smooth out but the problem must be really bad. I lowered my gain on the gyro and that seemed to help the tail but it still kicks real bad and the tank is still stormy.


i did not see much vibration in the tail fins so I'm hoping everything back there is OK but i will double check.

not having the pressure has got my attention. i changed the check valve for a new one and still nothing seems by the time it spools down the tank has leaked it all out or there was no pressure to begin with.

guess i need to remove the engine to check things and rebalance and dial indicated the fan again

how easy is it for the clutch stack to get bent, man i hope that is not it is there a way to check??

[Laurens]

What shims did you install in your engine? And whas fuel are you using?

[rstacy]

not having the pressure has got my attention. i changed the check valve for a new one and still nothing seems by the time it spools down the tank has leaked it all out or there was no pressure to begin with.

This would get my attention as well. Pull your fuel tank and do a pressure test. Your engine may be way too lean and causing your vibration problems.
We run 3 different Cline set ups and all 3 will blow a decent amount of pressure after a flight and when I forget to relieve the pressure and pull the pick up for fueling, it will squirt fuel for at least 4 feet, usually getting the person closest to me.

guess i need to remove the engine to check things and rebalance and dial indicated the fan again

how easy is it for the clutch stack to get bent, man i hope that is not it is there a way to check??

Not a bad idea but unless you crashed it really hard. I doubt that it is bent.

[Kinger]

If I had to venture a guess, I'd say you have an air leak either in a line somewhere or in the tank itself. You DEFINITELY should have pressure in the tank with the Cline setup.