burning oil

[rcmatt007]

My M3W has a S&S x-wedge 124 CI engine. S&S no longer makes nor supports the x-wdge. Anyway I now burn about 1 qt of oil per 200 miles. Worse when doing a lot of mountain driving (I live in the mountains) and using compression (actually vacum) on slowing down.
So here is what I have checked:
1: compression 80 PSI (normal as the engine has a lower compression on start up)
2: leak down test 100/94 left cylinder 100/95 on right (the talk morgan guys say it is normal)
3: checked the crankcase vent system and no oil coming out the vent into the intake

So I am wondering if this may be the valve guide seals as it clearly is the engine sucking oil under the deceleration vacum?

Any thoughts? Talk morgan has not been much help from here

[dontwantapickle]

Guide seals are a very strong possibility/probability.
124's are notorious for consuming a lot of oil.

[rcmatt007]

Mine did not consum any until about 15k plus. It also was about the same time the "dry" sump would slowly fill with oil when parked. The last vehicle I had that burnt that much oil was a 65 chevy belaire 6.

[dontwantapickle]

It's kind of a known issue with large air cooled engines.
They don't cool as efficently as liquid cooled and need to be built with greater tolerances
due to the expansion and contraction rates of the different types of metals in the engine.

Greater piston to wall clearances cause the ring to not seal as well when hot, causing oil to get past
them and be burned in the cylinder.

We use to only get around 30K out of the british air cooled twins (Tri, Norton, BSA) before they were
wore enough to be an issue. Let it go on long enough and and piston slap will become noticable.

Airplane engines have the same oil burning issue,
usually worse than motorcycle engines do, but your oil consumption rate is approaching airplane numbers.

The bigger to bore, the bigger the issue. 124 is a pretty big air cooled engine.
Knowlegable HD guys that I know say that 110 is about as big as safe before heat starts to really start causing problems.

Wet sumping indicates the oil pump isn't sealing like it once did and we all kow that too much oil in the bottom
isn't good for engine performance.

[rcmatt007]

thanks... sort of what I expected... just got a lot of smoke (pardon the phrase from talk morgan).. sort of a let us see if we can fix the oil pump (replace),,, or sell it as a "special collecter M3W)... Love the trike, but I also can move on

[Whiskerfish]

thanks... sort of what I expected... just got a lot of smoke (pardon the phrase from talk morgan).. sort of a let us see if we can fix the oil pump (replace),,, or sell it as a "special collecter M3W)... Love the trike, but I also can move on

You are much better than most of us (me especially) at adapting your life to a new program. Me, I detest change and fight it at every turn.

[Oldewing]

Valve seals are looking like the "smoking gun" Doc.....

[rcmatt007]

Valve seals are looking like the "smoking gun" Doc.....

And needs a new oil pupm. Looks like a trip to Morgan of new England as I do not want to do all that (and can I get the parts). While there, the rubber bushings for the CENTA drive (the compensator from the engine to the transmission) should be replaced. It means pulling the whole engine off.

Anyway, thanks for all the input.... more help than I got on talkmorgan