2012 December 14: I-Convert breather

Updated: 2012 December 14

First entry|Previous entry|Next entry|Last entry

This entry is extracted from a series of email exchanges between myself, Charlie Mullendore of Antietam Classic Cycle and Gordon Kline of MG Cycle. Both Charlie and Gordon were very supportive and helpful.

I thought I'd run this past y'all and see if you had some thoughts.

With 3000+ miles on my rebuilt I-Convert, it is still evacuating oil out of the breather and wetting my rear tire. As a reminder:

T3 engine with nikisil cylinders (original engine destroyed when oil filter came loose, I was told).
Pistons are fit with rings from MG Cycle: MG# 13060600
Cylinder heads have been reworked (valves ground, new guides, etc)
Compression each side is 145 PSI hot (checked yesterday)
Leak down each side is 8% - 9% (checked yesterday - this is at the very bottom of my leak down tester gauge...right next to the Set section; low begins at 10%, for whatever that is worth).
Breather is a loop frame breather. Hose to atmosphere goes straight down, then across the frame, exiting at the rear transmission mount (just like on my Ambassador). The breather has only the spring loaded check valve and not the ball check valve (I've verified that).
I've got a sump extension/windage plate fitted and run 3 quarts of oil (no more):
Both plugs are a nice color and match closely.

Yesterday I rode it 200 miles up the Mogollon Rim and back down. 70 MPH most of the way with a couple of very brief excurssions up to 75 MPH. Certainly nothing excessive. My rear tire has engine oil on it, again.

Good grief, I can flog my Ambassador with the same breather and never have trouble with oil coming out of the breather. To state that I am sick of cleaning the bike of oil is a gross understatement.

I've got a catch can I can fit (oh joy). Or I can try to engineer a larger capacity breather to better handle things (oh joy).

I'm at a loss. I really enjoy riding the I-Convert but I hate the mess all that oil creates and the danger of an oil covered tire.

What am I missing?

Regards,

Gregory Bender

First entry|Previous entry|Next entry|Last entry