MVVS 45 Bearing / Oil Seal Issue?  
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All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Manufacturers Direct Support Forum >> MVVS Support >> MVVS 45 Bearing / Oil Seal Issue?
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MVVS 45 Bearing / Oil Seal Issue? - 7/2/2007 6:22:34 PM   
thappy


 

Posts: 2
Joined: 6/16/2004
From: Paradise, NL, CANADA
Status: offline 		I have a low run time MVVS 45 that I am running with an MVVS canister, Xoar 20x10 3 blade prop and mixed 3% with Bel-Ray H1R synthetic 2-stroke racing oil. I have been more than satisfied with the performance. I had accumulated a couple of dozen flights without issue when I experienced my first problem; after flying for several minutes, engine RPM dropped significantly so I reduced my throttle and landed the aircraft. Following the landing I verified the ignition supply batteries and did a visible inspection of the engine for all the SNAFU's that can happen while at the field.
There was an audible squeak (not metal on metal, more like rubber on metal) from the engine front. There was also a loss of smoothness in the bearing(s) without a significant increase in radial or axial play. I decided to remove and dismantle the engine for inspection, suspecting front bearing failure. The following is what I found:

The crank case housing and rear bearing were discovered to be clean and well lubricated. Forward of the rear bearing was contaminated with what looked like carbon. This contamination continued into the front bearing and in fact had blocked lubrication from reaching the front bearing race and cage. The front bearing is an open 6002/C3 deep groove ball bearing with a separate rubber oil seal mounted in front of the bearing. The oil seal does not contact the engine shaft but a steel bushing over the shaft. I removed the front bearing and seal for detailed inspection. The bearing was dry, completely contaminated with the black residue, rotated roughly and squeaked. I flushed and lubricated the bearing and was surprised to see there was little or no visible damage to the bearing. I inspected the oil seal and compared it to a new seal. There was significant wear in the lip of the oil seal that is in contact with the steel bushing. This oil seal lip is inside and directly in line with the inner race of the open front bearing. The carbon like residue seen forward of the rear bearing was coming from the front seal and contaminated the front bearing including lubricant access.

I am replacing the front bearing since it was starved of lubricant and subjected to a significant amount of heat as a result. I am inquiring about the suitability of using a shielded bearing (using just one shield facing the seal) instead of the standard open bearing. Or, any other solution someone might offer.

Oh yes, and for those who might be searching for bearing data, the rear bearing is a 6203/C3 open bearing...

Thanks in advance,

Todd Hapgood
       Post #: 1

RE: MVVS 45 Bearing / Oil Seal Issue? - 7/2/2007 8:59:25 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		Put in a 6202-2rsr (double rubber seal) bearing and be done. In my engine I lubricate the seal with a drop of oil every now and then. No problems so far. A ball bearing does not need much oil, but black goo from the seal is not to it's liking. The seal being rubber, and in contact with the rotating ring does like some oil though. Lack of seal lubrication makes itself noticed by not running quite freely.
Current MVVS engines have two 6002-2rsr deep groove double seal bearings, and do not rely on oil to get past the shaft anymore.

_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to thappy)
       Post #: 2

RE: MVVS 45 Bearing / Oil Seal Issue? - 7/3/2007 10:58:30 AM   
thappy


 

Posts: 2
Joined: 6/16/2004
From: Paradise, NL, CANADA
Status: offline 		Thanks for your very quick reply Pe.

I assume you meant one 6002-2RS for the replacement front bearing. I was wondering why the discrepency between the Evolution and MVVS operators manual exploded views but now understand. Do you know what facilitated the change to two bearings? Also, do you feel one standard sealed bearing is sufficient?

Thanks again,

Todd Hapgood

(in reply to pe reivers)
       Post #: 3

RE: MVVS 45 Bearing / Oil Seal Issue? - 7/11/2007 7:25:54 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		The first engines had a single bearing and a separate rubber seal.There also was some extra play that allowed the engine to run with more power. This was not received well by customers, who kept sending their engines back for repair. (This seal likes a drop of oil every now and then).
So they changed the design, and now there are two double seal 6202 RSR bearings up front, that can take all the abuse that a prop can impart on them. The bearings are grease filled, and should last the life of the engine if the user cools the engine like he should.

_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to thappy)
       Post #: 4

RE: MVVS 45 Bearing / Oil Seal Issue? - 3/22/2008 12:29:56 AM   
negy1


 

Posts: 75
Joined: 4/30/2003
From: cobar, AE, AUSTRALIA
Status: offline 		can i fit the two new front bearings and still use the prop drive or have they bean changed ie redisigned both my front and rear bearings wear stuffed only had about 3 gallons of fuel through it motor performance is great but for a motor that is 30% higher in price of a da 50cc should not have bearing problems i am realy dissapointed in thi 58cc motor i have a 35cc mvvs and it a gem thanks

(in reply to pe reivers)
       Post #: 5

RE: MVVS 45 Bearing / Oil Seal Issue? - 3/22/2008 1:54:25 AM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		I think your loong sentence should read like this?

Can i fit the two new front bearings and still use the prop drive, or have they (bean) changed ie redisigned both my front and rear bearings?
wear stuffed only (I do not understand this!)
Had about 3 gallons of fuel through it. Motor performance is great but for a motor that is 30% higher in price of a da 50cc should not have bearing problems. I am realy dissapointed in thi 58cc motor. I have a 35cc mvvs and it a gem. Thanks

Use a double seal front bearing, and use the original spacer ring, if fitted. That will do fine and seals well.
A drop of oil on the seal every now and then to keep it lubricated works as well. A little care goes a long way.



_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to negy1)
       Post #: 6

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All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Manufacturers Direct Support Forum >> MVVS Support >> MVVS 45 Bearing / Oil Seal Issue?
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