Avenger 85 help

[NeedSpeed]

Hello. I'm new here. I recently purchased an Avenger 85. The crank seals were eaten away in record time. After replacing them (lubed) they still leak. I drilled some small holes in the upper part of the bearing shield hoping to get more lubrication. They seem to seal with pressure but not vacuum. I have more seals on the way. Did I mess up by drilling holes in the shields? How is everyone keeping their seals lubed? Thanks for your time.

 

[mony0_3]

I had the same problem and put my top end on a YD100 bottom end and have no more problems with seal leaks! I put the YD100 top end on the Avenger bottom end but haven't run it yet.

 

[ImpulseRocket]

I run with no bearing seals/shields at all in my motors, so no the holes in those won't cause a problem.

Does the area where the crankshaft meets with the seals have any damage at all?

 

[NeedSpeed]

I had the same problem and put my top end on a YD100 bottom end and have no more problems with seal leaks! I put the YD100 top end on the Avenger bottom end but haven't run it yet.

What's the difference between the two? Case volume?

 

[NeedSpeed]

I run with no bearing seals/shields at all in my motors, so no the holes in those won't cause a problem.

Does the area where the crankshaft meets with the seals have any damage at all?

Nice! I figured it should be fine as The shields don't do much for sealing anyway. The crank looks decent with minimal machine scaring and decently trued compared to other engines I've had. I'll polish the surfaces a bit before the next seals go on. Does anyone know how much vacuum these engines should hold and for how long?

 

[GW's Motorized]

What's the difference between the two? Case volume?

Wrist pin size. Most yd100s have a 10mm wrist pin. If I right @mony0_3 lucked out and got the 12mm one

 

[NeedSpeed]

Wrist pin size. Most yd100s have a 10mm wrist pin. If I right @mony0_3 lucked out and got the 12mm one

I fail to see how this would help the crank seals.

 

[ImpulseRocket]

Vacuum leaks are more prevalent than compression leaks due to how the seals are shaped. The relief on the inside of the seal creates a pocket where compressed gasses collect and apply pressure to the seal helping it seal better. That same design allows vacuum to pull outward on the seal surface, reducing it.

If there isn't any damage present I almost wonder if your crank isn't slightly undersized.

 

[GW's Motorized]

I fail to see how this would help the crank seals.

It worked for him. I guess the yd100 had better crank seels

 

[ImpulseRocket]

It worked for him. I guess the yd100 had better crank seels

Not really better seals, but the yd/ld bottom ends use 2 wide seals instead of a wide and narrow.