Aux engine flat 4 cylinder gas/magneto ignition starter ??

[fireman]

We acquired a mil flat 4 cyl. gas engine (looks like Lycoming culinders) that we are going to use as a water pump engine. On trying to start the engine the starter engages but continues to run after the switch is turned off. The starter when removed operates normally (disengages when switch is turned off). When reinstalled it continued to run again. We tested the attached solenoid with battery removed from the starter and the solenoid seems to engage & disengage normally even when mounted to the engine. We are mystified why the starter stays engaged & running with no power to the solenoid switch side!

Any ideas? Oh yes, this engine was new in the box when we got it. I have no id # for it but will attach pictures tomorrow. Thanks

 

[tlm47201]

Have been pondering the same setup. Sounds like the starter drive needs oiled good, or starter is needing shimmed away from the crank. Try loosening the starter mounting slightly and try it. If it spins out correct, it needs repositioned.

 

[Boatdocter]

Do you have any pics of the engine and or of the pump project?

 

[fireman]

I will get pictures today.
We did grease the bendix gear and it was of no help. The starter has been removed & installed 3 times, so its clearances have changed some each time I am sure.

What makes no sense to me is HOW does the starter MOTOR keep running after the solenoid is de-energized (switch turned off)_?? Is there some internal contacts that stay in contact until the bendix throws out (therefore supplying 24v to the starter even though the solenoid actuator is released?)? It is not as though the bendix is staying engaged when the starter stops.... it does not, but the starter motor never stops as long as the battery cable is hooked to the battery lug on the solenoid....????

 

[fireman]

The tag identifiys it as a:
Engine, Military Standard
4 cyl
25hp
Model# 4A084-4
Manuf- Teledyne

This engine is also used with Gensets per another tag.
These pictures did not come out to well (fuzzy). I will try again friday for better ones.
All help is appreciated!!

 

[fireman]

Another one....

 

[fireman]

One last one of front of engine...(pull start)

 

[BobM]

Isn't teledyne continental?
Anyway, does the starter still run with the cable off? If so, then it almost has to be catching on the flywheel teeth. You could check by hooking jumper cables up as your power lead and quickly removing the power upon startup. If there is no electrical power then the starter has to be carried along by the teeth hanging.
Just my opinion.

 

[fireman]

I'm sorry!!! I guess I did not make myself clear. This was an initial test of the engine hookup and it has no fuel at this point, so the engine cannot start. The starter is not hanging on a running engine. This happens when you just touch power to the switch lead on the solenoid... the engine continues to crank (without starting of course) with no power applied to the solenoid switch contact. Battery is only applied at the solenoid battery lug at this point. When the battery is disconnected the starter then stops.... & that is the ONLY way to get it to stop!
Help!

 

[BobM]

Then this almost has to be a bad solenoid IMHO. The solenoid is supposed to pass on the electrical power and STOP that power.

 

[randyscycle]

Not sure of the exact starter design, but if the drive is hanging and shares the same engagement arm as the one that closes the contacts to send power to the motor, then it would make sense that if the drive is staying engaged to the flywheel then the solenoid contacts are also still closed.


Is there a chance the flywheel ring gear is on it backward? The teeth in most ring gears are cut so that they sort of throw the starter drive out of engagment when the engine is either started or the starter button is released.

 

[fireman]

We disaqssembled the solenoid today. All the parts seem good.... EXCEPT the plunger slug & sleeve were corroded thru the anodizing on the sleeve. There was no residue however it is slightly rough. We are going to try polishing the sleeve & slug with some 800 grit emery & see what happens. If it still sticks, we may put gas in it & see what happens when it starts.... I just hope the starter does not stay running then... no telling what might happen!

 

[49willys]

GPU engine....

Hi,
Neat engine..

Be very carefull what oil you use in that engine..very carefull.

Alot of GPU's (Ground Power Units) back in the day used Continental aircraft engines.

They used aircraft oil as well, be sure you find out for sure what oil to use. If you put
volkswagon oil in you may do ok, if you put vehicle engine oil in you may ruin it and will certainly ruin it if it is supposed to use aircraft oil.

Just a word of caution as i have limited experience with GPU's.

Aircraft air cooled engine oil for Cessnas, Pipers etc...is available at your nearest
small airport as well as parts..

I have some folks i can ask if you have any more questions or can provide clear pictures and more info..

Tom....

 

[CCATLETT1984]

RE: GPU engine....

that is the 4A084 engine used on the 10kw gensets.

 

[fireman]

After polishing the soleoid sleeve & piston, it works... sometimes! Now I need to find a new soleoid &/or starter assembly.
See new post. Thanks

 

[Boatdocter]

Saturn surplus should have the parts or maybe a rebuilt starter but not any nos.

 

[fireman]

Thank you.... i will check with them.