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cliff600 · 02-09-2012, 02:55 PM

I just got a Raptor 90 with an OS .91 SZ and got it all programmed up and test flew it today. I have the gov. set at 1800 in normal mode, after running it, it seemed really high. It has a 611 gyro on it and the tail is ever so slightlty drifting to the right (heli yawing left). I was getting a ton of smoke, but the engine seemed to be warm to me. What kind of temp should I get and where should I check it, I can't put my finger in the bottom of the engine because of the pump.

Any help would be appreciated.

KeithT · 02-15-2012, 04:02 AM

I can't really help with the temperature issue - mine has access to the base-plate (no pump), but even then, that has ridges on it which make it difficult to test. I would guess tuning will have to be 'by the basics' - hover test, climb-out, smoke trail, return to idle etc etc.
What governor are you using? What setting for the gyro? Give us some more info

ticedoff8 · 02-21-2012, 12:20 PM

Raptor 90? Which version? (G4, SE - ??).

1800 is the right head speed - I use 1750 & 1850 on my 2 Raptor 90SE.
But, check your gear ratio & the setting on the gov.
I use an OS 91HZ-PS & the YS 91SR-3DS.
The OS likes 15,000 engine RPM and I use an 11 tooth pinion & a 91 tooth main (the white main gear). That is 8.27:1 and at 1800 head speed, then engine is turning at 14,890 - close to the sweet spot.

The YS likes to be closer to 16,000. So I use a 11 tooth pinion & 95 tooth main. That's a 8.63:1 ratio - at 1800 head speed, thats 15,500 - again, pretty close to the sweet spot.

Check your gov setting to the proper gear ratio - that is important.
Then, try to check your head speed when the gov engages - this can be done with a partner using a Skytach or a "peak hold" optical tach (like the Align Multi Tester) strapped to the side while flying.

As for temps - if you place your finger on the backplate after running and it is warm but not HOT, you are in the ballpark for needle settings. Use an IR thermometer pointed at the head - near the glow plug - and if you are less than 200F, you are good.

cliff600 · 02-22-2012, 05:24 PM

Thank you. I had the wrong gear ratio in the gov. I did fix that, but I have not gotten to fly it since.....been too cold. Thanks for the rpm help too.

02-09-2012, 02:55 PM	#1 (permalink)
cliff600 Registered Users Join Date: Nov 2005	I need a little help I just got a Raptor 90 with an OS .91 SZ and got it all programmed up and test flew it today. I have the gov. set at 1800 in normal mode, after running it, it seemed really high. It has a 611 gyro on it and the tail is ever so slightlty drifting to the right (heli yawing left). I was getting a ton of smoke, but the engine seemed to be warm to me. What kind of temp should I get and where should I check it, I can't put my finger in the bottom of the engine because of the pump. Any help would be appreciated. __________________ Where does the white go when the snow melts?

02-15-2012, 04:02 AM	#2 (permalink)
KeithT Registered Users Join Date: Nov 2008	I can't really help with the temperature issue - mine has access to the base-plate (no pump), but even then, that has ridges on it which make it difficult to test. I would guess tuning will have to be 'by the basics' - hover test, climb-out, smoke trail, return to idle etc etc. What governor are you using? What setting for the gyro? Give us some more info __________________ Raptor 50 TitanSE - AR7200BX + RJX head Raptor 550E with a flybar!! Align 500 pro with Speed fuselage mCPX V2

02-22-2012, 05:24 PM	#4 (permalink)
cliff600 Registered Users Thread Starter Join Date: Nov 2005	Thank you. I had the wrong gear ratio in the gov. I did fix that, but I have not gotten to fly it since.....been too cold. Thanks for the rpm help too. __________________ Where does the white go when the snow melts?

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02-21-2012, 12:20 PM	#3 (permalink)
ticedoff8 Registered Users Join Date: Jan 2010	Raptor 90? Which version? (G4, SE - ??). 1800 is the right head speed - I use 1750 & 1850 on my 2 Raptor 90SE. But, check your gear ratio & the setting on the gov. I use an OS 91HZ-PS & the YS 91SR-3DS. The OS likes 15,000 engine RPM and I use an 11 tooth pinion & a 91 tooth main (the white main gear). That is 8.27:1 and at 1800 head speed, then engine is turning at 14,890 - close to the sweet spot. The YS likes to be closer to 16,000. So I use a 11 tooth pinion & 95 tooth main. That's a 8.63:1 ratio - at 1800 head speed, thats 15,500 - again, pretty close to the sweet spot. Check your gov setting to the proper gear ratio - that is important. Then, try to check your head speed when the gov engages - this can be done with a partner using a Skytach or a "peak hold" optical tach (like the Align Multi Tester) strapped to the side while flying. As for temps - if you place your finger on the backplate after running and it is warm but not HOT, you are in the ballpark for needle settings. Use an IR thermometer pointed at the head - near the glow plug - and if you are less than 200F, you are good.

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