My 58cc Evolution engine seems to have developed a little free play in the crank. I can move the crank in and out with a slight click. Not more than a thousandth or two. My thought is a front bearing.

It has about 6 hours on it.

Out of warranty. Have had it on another plane and not flying it caused the warranty to expire.

Using evolution synthetic oil mixed 30:1 with Hi octane gas as recommended.

Is this something I can fix? If so, how?

Is it something I should worry about?

Thanks in advance for any help.

Bill

Did you put a dial indicator on it? That small of end play (my opinion) should not make a ckick. Does the bearing sound good and feel smooth when you hand crank the engine over? I will let the real pros give the real data. Capt,n

Cap, it's front to back not side to side. Ran fine last week. Noticed it putting it back in the car. It is more of a metallic sound as I pull on it, not necessarily a click. Poor description on my part.

Bill

look at this link, [link=http://www.rcuniverse.com/forum/m_7495471/tm.htm]Evolution 58 crankshaft movement [/link]

It depends on the prop drive. The 58 MVVS engine had two different drives. One with steel insert, that also serves tobut up against the front bearing and bear against the seal lip, the other an all aluminum prop hub with a separate pressure/sealing ring.

The former should have the drive torqued up so it locks the front bearing inner ring on the crankshaft. This torque is about 33Nm, applied with a 12.8 M8 bolt and pressure ring bearing against the central steel part only. After fitting the prop drive, final torque of the M10x1 central bolt is not to exceed 22Nm.

The latter has the distance ring loctite fitted on the shaft. Heat can cause the loctite to let go, and increased longitudinal play is the result. If play increases to 0.5mm or more, it needs to be taken care of. I do not know the torque down of this version, but it should be similar. The taper is steeper than the steel version.
You need to know what you are doing. If not, send the engine in for maintenance.

Duber, Thanks for the info. Very informative. It appears that a small (.5mm) movement in and out
is ok.

Bill

Thanks Pe, I always look forward to your responses as one of the respected engine gurus. I can count on you being accurate.

Again, Thank you.

Bill