What happened to my engine

[kevin king]

I unfortunately hit  the soft damp grass covered field and after cleaning up the engine it feels abnormally loose, and rattles when i turn the prop over. What could be wrong? Its a fox 35.  It feels like there is slop or play in it now.

[Dave_Trible]

Maybe nothing is wrong but to check,  remove the backplate.  Inspect the rod and backplate for cracks and be sure there is no pieces of broken metal loose inside.  Engines that hit hard on the nose can jam the shaft backwards and if hard enough, hit and crack the backplate and bend the rod.  I did this once as a kid hitting the concrete with enough force that Dad had to extract the crankshaft out of the fuel tank on my Firecat.  He sent the mess to Duke Fox for repair.  Duke just sent a new engine for about $5.00.  The case and backplate are simple castings that aren't bullet proof.  If all looks OK in yours put the backplate back on and mount it on your test stand for a run to see that the engine runs normally without a lot of shaking.  It will either be good to go...or find a replacement on eBay.

Dave

[kevin king]

Dave, when i took the engine apart to clean it, the backplate was fine and I did not see any metal inside. No visible cracks on the connecting rod that i coud see. Maybe I need to take another look at it. If not i will find out tomorrow at the flying field.

Kevin
 

[kevin king]

update. took the engine off the plane, removed the back plate, and decided to pop off the connecting rod from the crankshaft. Then i could not get it back on, then it got stuck. So now the hole in the connecting rod looks beat up. Unreal. I see another break from the hobby approaching.

[GERALD WIMMER]

Sorry to hear of your dilemma, should pull the liner before removing the rod from the crankshaft on most engines of the drop in liner type.
A new rod can be had from Mecoa :
https://www.mecoa.biz/shopexd.asp?id=4570

The drive/thrust washer can get stripped with a good crash and I suggest you check that it is fully engaging with the crankshaft and not slipping.

Regards Gerald

[Perry Rose]

Hobby Towne in Baton Rouge has Fox .35's for $35.00 each or 3 for  $100.00.

[kevin king]

Fortunately today i gave the engine to the friend and club member who has the parts and know how to fix it. Thank you Larry Maltman!

[Trostle]

Fortunately today i gave the engine to the friend and club member who has the parts and know how to fix it. Thank you Larry Maltman!

So, what is being fixed?  How is it going to be fixed?  Inquiring minds want to know.

Keith

[kenneth cook]

                The Fox .35 takes ground pounding quite well. I can only say if the engine was turning over very easy, I would look closely at the glow plug to insure the post didn't break out. In addition, noises can happen when the prop nut is not fully tightened or the drive washer isn't properly seated on the shaft cogs. Clicking and funny feeling like the rattles you mentioned. Many times the backside of the drive washer becomes a bit compromised from backfires and can develop burrs or oblong slightly. When the prop is installed, it's imperative to insure it's seated correctly when you tighten the prop .

[kevin king]

So, what is being fixed?  How is it going to be fixed?  Inquiring minds want to know.

Keith

Hi Keith, Not being an engine guy myself  the first problem Larry has is un jamming the connecting rod from the web of the crankshaft. The piston has also turned in the sleeve all thanks to me. Next he wants to take the conrod out and inspect it for straightness, check the wrist pins, and check for a bent shaft.

Kevin

[kevin king]

Thank you for the tips Kenneth, Gerald and Perry.

[phil c]

Hi Keith, Not being an engine guy myself  the first problem Larry has is un jamming the connecting rod from the web of the crankshaft. The piston has also turned in the sleeve all thanks to me. Next he wants to take the conrod out and inspect it for straightness, check the wrist pins, and check for a bent shaft.

Kevin

Sounds like Larry knows what he is doing.  The Fox is about as simple as they can get.  So it's pretty easy to clean up and check the parts before putting it back together.