YS 91sr Not Starting

[p00rboi]

Any input will be welcome. I have a brand new YS 91sr with the Hatori SB19FH that started and ran for about a half of a tank and then shut off. Since then I have been unable to get it started again. I have replaced the glow plug and reset the needles to the factory recommended settings. I have checked the check valve and the diaphram; all seems well. When I removed the muffler there was a substantial amount of fuel in it. I don't know what else to try. Please help a freak complete the maiden flight with his new Trex 700.

[DavidH]

You sure your glow igniter is lighting the glow plug? I have seen others have the same problem. And come to find out there glow igniter was not lighting the plug.

David

[p00rboi]

That also crossed my mind, so I unpluged the 2-in-1 igniter lead and used a Hobbico long shot and I checked that the plug was being ignited out of the heli. I am wondering if I should use a wired glow igniter and a power panel and up the heat a little.

[JimLerch]

I don't know why this works, but it does. Assuming the glow plug points towards the nose of the heli, have a helper tilt the airframe so the nose points skyward, and re-attempt starting.

I find its best to do this on a table, with the rear of the skids working as the pivot point. Have the helper hold the tail boom and one blade grip. Make sure the helper knows to not let go under any circumstance!

When I don't have a helper handy, tilting it back about 45 degrees will usually get it done as well, but it seems much harder.

I don't need this trick very often, usually only after the Heli's been sitting for a week or longer (rare) or if I hydro locked it (also rare).

There is also the possibility that tilting the airframe back does absolutely nothing but kill time, allowing the motor to "fix" itself. I don't know, but once you see it work, its kinda spooky!! :shock:

[p00rboi]

Thank you Jim. Tilting the heli was the key; after leaning out the low end into the operating settings.

[JimLerch]

Thank you Jim. Tilting the heli was the key; after leaning out the low end into the operating settings.

Spooky, yes? :YeaBaby:

I am glad to hear you got it running again! Just be careful with it and listen for detonation (frying bacon sound). If it starts eating glow plugs, you need to either richen the mixture, or add a head shim.

Don't do what I did and keep stuffing glow plugs in it thinking it will fix itself, else you will end up with this:

http://lerch.no-ip.com/Heli/YS-91-SR/Piston-Head.jpg

[geepfreek]

hey I'm the helper, we were able to richen the heli back up after it finally started and after the second tank we didn't have to tilt it any more... but wanted to say we did richen the motor back up

[dogg5306]

Man... I'm experiencing the same thing now...:-(
The engine has gone lean last week (it shut itself down)... no more way to start it up again!
Fuel lines are OK, just as the check valve... the plug is also fine...

I'm gonna try to tilt it (90°)... and if it still doesn't start I'll be so angry at Yamadas that I'll go back to OS ones!

[dogg5306]

It worked!!!!
1st class solution... I really don't understand why but it works fine... now I can start my engine like usual i.e. the heli being on a horizontal plan!

Thanks again, Jim.