Thorp Air Command - T18.net

Well...went out to fire up the Sky Machine and the starter is making a terrible grinding noise ? [:0] This would have been about the 6th start on a "new engine" and starter. Sky Tec 149-12LSX starter. First thing I did was go to the Sky Tec online trouble shooting section. The prelim inspection trouble shooting section (smell, heat, smoke and "grinding noise") would suggest it is the starter...only the grinding noise, no smoke, smell, heat, etc. I did proceed further with the trouble shooting and even took out the battery (PC-680) and charged it and went to 2 battery stores and had them check it ( 2 stops to verify ). Both indicated a charged battery with about 13+ volts and a good load check. Put the battery back in and checked all the connections (including the grounds). Still mucho grinding noise. To check the starter solenoid, I jumped directly to the starter...same grinding noise. Starter wants to engage (spin prop), but only for a split second, then starts the grinding noise (prop does not spin). Pretty sure it is the starter. Anyone have similar problems with this model starter ? Maybe I am missing something ? The starter is covered under the Aero Sport Power Engine warranty (3 years parts and labor from the first flight). Before I possibly send off a good starter for replacement and embarrass my good name anyone have any imput ?

RB (Sparky)
NX115RX

You don't by chance have a 122 tooth ring gear?
Other thought is , do you have a jumper from the battery lug to the starter solenoid.
Is the solenoid coming all the way engaged? Its a Ford starter with a different moount.

Not sure about the 122 teeth ? The engine and starter came right from the Aero Sport Power test stand to me. I have not changed anything from what was sent to me from Aero Sport. First 4-5 starts on my A/C went just fine. About 2 spins on the prop, fired right up. This "grinding" just happened on my last attempt ? I suspect it may be the solenoid on the Sky Tec starter ? Checked all the attach bolts and connections on the starter...all tight. It sounds like the drive is not fully engaging the ring gear. Unless someone in the group has any more info on this pickle, I'll call Aero Sport Monday.

Sparky

Lets go the other direction, solenoid is not releasing, starter drive staying engaged.
Is the starter an open face or enclosed?

Bill: Doing some research on the Vans site, I found out some interesting info about the Sky Tec starter. I have 149 teeth on the ring. The Sky Tec starter is a 149-12LSX. The 149 indicates the number of teeth, so I am pretty sure the stater and ring are a match. The Vans site does mention the Sky Tec light weight starter has had problems with the starter mounted solenoid. The stater wants to engage the ring gear, but it appears to not make full contact. When I inspect the starter the drive appears to be fully retracted...start switch off. I plan to call Aero Sport Monday morning. I will report back with info.

RB

There is two ways to wire the starter.
Most wire the battery cable from the start solenoid to the starter solenoid with a jumper from the battery lug to the starter solenoid.
the , belive it the preferred way, is to run the battery cable straight to the starter solenoid and wire from the start solenoid to the start solenoid. This lets the firewall solenoid act as a switch. I know to many solenoids in this subject.
Sounds like the starter solenoid is not totally relaxing.

A little confused trying to picture your wiring diagram. [:(] I don't think it is a case of my incorrect wiring as it has worked OK from the first start. The starter hook-up was done in accordance with the NL's, Tony Benglis and as I reviewed the Sky Tec site (jumper 101), my starter set up was wired according to their "typical certified A/C wiring diagram." The starter came installed from Aero Sport with a jumper wire on the starter to allow a "one wire" hook up to the firewall starter solenoid...4ga wire, via a master solenoid/master switch/start switch. Having reviewed the Vans site, I am convinced it is the solenoid on the starter (or the drive, not sure what type it is...no "Bendix drive" installed on this LS series starter). I tried to down load the Sky Tec site (with their diagrams), but as usually I can't do it.

BTW...I did run a jumper wire directly from the positive terminal on the battery directly (by passing the firewall starter solenoid) to the starter, the result was the same "grinding noise" from the starter and a lack of engagement to the ring. [:p]

RB

Rich,

This phenomenon is not new to this series of SkyTec starters. I had one come apart (the bolts just let loose.) SkyTec made good on it even though it was a couple years old. You should try another starter, if you can, to confirm the starter is the issue. My local starter guy has replaced the solenoid for me, on occassion, as these are really car units with a different nose piece. In the case of your new one, let SkyTec have a shot at it.

By the way, I have found the use of a cylinder base wrench to really speed the removal and installation of starters on Lycoming engines.

_________________
Bob Highley
N711SH
SN 835
KLAL

Roger that Bob. I suspect it is the starter. Calling Aero Sport Power today to see what they have to say.

RB