Possible sign of imminent engine failure (582 blue top)

[Bluey]

Hi all:

 

I've got a blue top 582 (oil injected) motor on my edge x. I did the 25hrly today and as usual did the cyclone bearing tests. The front cylinder was 0.05mm and the rear 0.04mm. The test was repeated numerous times for each and the results are reliable. In the past they have always been around 0.035mm to 0.04mm for both front and rear. How worried should I be. I plan to go for a fly early Sunday morning and then re - test after that. I expect to do around 3 - 4 hours of flying before testing. The test will be performed once the engine has properly cooled.

 

Bluey.

 

 

[Guest Crezzi]

If it was me I'd stay overhead the airfield or you might be testing your new tundra undercarriage

 

Its been a long time since I owned a 2-stroke but the results from the bearing test would be expected to show a significant increase in play over the first few hours as the motor beds in. Then the play won't / shouldn't change for a long time. IMO once the play starts increasing again it will do so rapidly, and the crank is really running on borrowed time. But you are P1 so its your decision.

 

Out of interest how many hours has the crank done ?

 

Cheers

 

John

 

 

[Bluey]

Nearly 550 hours since its last rebuild.

 

 

[icebob]

Hi,

 

my two older motors(none oil injection) when they got the figures of 0.04 front bearing and 0.055 rear i got another 16 hours before that motor failed and the other motor did another 105 hours before it was overhauled a seal leak that had me rebuild while replaceing all the seals.. hope that sort of helps.

 

I know the book says 300 hours but if your bearing wear is unchanged and all other tests are within the specs then cautiously give it a go.

 

I will say motor one failed in flight and was byond rebuild where as motor two did not fail and was rebuilt- there is the cost thing. In hind sight it would have been cheaper to rebuild the failed motor long before it gave up the ghost, oh and less mess to clean up, if you know what i mean.

 

Bob.

 

 

[BLA82]

I know the book says 300 hours but if your bearing wear is unchanged and all other tests are within the specs then cautiously give it a go.

In all honesty Icebob that comment is a bit of a worry, I believe if the book says 300hrs than it's 300hrs no questions asked.

 

 

[icebob]

Hi BLA82,

 

Yes the book does indeed say 300 hours, if i do all the appropriate tests and that does include a total strip down and measure everything and all are well within the manufacturers specifications then i would feel confident of reusing the motor "on condition"for at least another 100 hours before retesting.

 

I know most owners would not have available the facilities i do for engine component testing and overhaul and if i did not have them i too would stick to the 300 hours for sure.

 

It has been electrical items like alternators and voltage regulators that have let me down more so than the motors. an interesting thing here, when the alternator packs it in it is usually very close to or just after the 300 hours anyway, a strange phenomenon in deed? That was on both motors too.

 

Bob.

 

 

[skeptic36]

In all honesty Icebob that comment is a bit of a worry, I believe if the book says 300hrs than it's 300hrs no questions asked.

Hi Bla,

I think there are a lot of people out there with engines well over the 300 hrs, have a look here :http://www.recreationalflying.com/forum/engines-props/26662-how-many-hours-out-your-2-stroke.html

 

If you are flying with the idea that your engine can stop at any time (within glide distance of a landing site) then there are a lot worse things that can go wrong than an engine failure. Having said that it hasn't happened to me yet, I hope I still say the same after it does i_dunno.

 

When I read of the cost to overhaul or replace these little motors:ah_oh: ( i can replace my 250 cc ag bike for less and it comes with disc brakes, suspension, stainless exhaust, wheels, gearbox, lighting system is four stroke and even has a seat) I hope mine goes well past 300 hrs or I will be grounded for some time with the economic climate the way it is.

 

And that will not be good...........

 

Regards Bill

 

 

[Bluey]

I just did a retest on the engine

 

I'm a bit perplexed, I just did a re test on the engine and this time the readings were 0.035 for the front and again 0.04 for the rear. I don't know whu this is the case. I did the tests the same way as yesterday. I repeated each measurement 5 times and the results were the same each time. It's possible the micrometer may have a little play in it when the syringe is pulled. Just maybe, if the syringe is pulled too fast then it may be possible that the inertia of the rising micrometer needle may not stop at the highest point the piston reaches???? Thats about all I can think of at this stage. Either way, I will retest again tomorrow after some flying. It is interesting that todays measurements were only different for the front cylinder. The rear cyclinder returned the same readings as yesterday. Todays retest was after a 20 minute ground run late yeasterday afternoon.

 

After the testing today, I flew for 25 minutes at last light and just to get some practice I shut down the engine from 2500 and then landed. It sure is very quiet and peaceful when you do that.

 

Bluey.

 

 

[icebob]

Hi Bluey,

 

Yes it is possible to get false readings, unfortunately it is a knack at getting it reasonably accurate and that comes with practice and time.

 

Getting someone else to do it too is no help if they have not done much of that type of testing either.

 

Check your maufacturers web site they may have stated 400 hours so it legally is 400 hours.

 

Bob