Oil loss after rebuild???

[Ecarta]

Ok after the rebuild my 2004 KDX200 runs like a champ, quick, responsive it's great!
But one problem. I'm losing oil, about 2 ounces per ride. Enough where it goes from top to bottom of sight glass after 1 ride. How can it be worse after a rebuild?? I have no visible leaks, no puddles, no oil spray anywhere. The oil looks creamy black after 1 ride.

The main reason I did the rebuild was I wanted to change the crank seals/bearings and water pump seal. What are the chances they are bad already? Installed wrong?

Can anything else cause this? Plus my oil turns black very quickly. And yes it does seem to smoke more than it should. Im running 32 to 1 Maxima semi synthetic 2 stroke oil and Valvoline 10W40 Full Synthetic transmission oil....Please Help!!

[Slick_Nick]

Was it doing this before? How badly was the crank grooved around where the seals sit? If it was really worn, new seals won't be able to seal up. The easiest way to figure it out is to do a leakdown test.

[Slick_Nick]

How's your coolant?

[Ecarta]

Was it doing this before? How badly was the crank grooved around where the seals sit? If it was really worn, new seals won't be able to seal up. The easiest way to figure it out is to do a leakdown test.

I do admit it always did smoke a bit, But im thinking that was more of a water pump seal leak. My transmission oil hardly if ever went down before.
I did not notice any groves on crankshaft seems like above average condition to me!

[Ecarta]

How's your coolant?

So far coolant is holding true, no appearance of leaks, overflow bottle is the same

[pumpguy]

I wonder if you're building up pressure in the transmission due to heat build up and a clogged vent line? If the vent line isn't open to atmosphere, the pressure build up will force oil out through the path of least resistance.

[Ecarta]

I wonder if you're building up pressure in the transmission due to heat build up and a clogged vent line? If the vent line isn't open to atmosphere, the pressure build up will force oil out through the path of least resistance.

What vent line are you speaking of? That hose that goes from behind kickstarter to the airbox?

[pumpguy]

Yeah, I think thats the gearbox vent hose.

[KDXGarage]

How quickly after riding are you checking the oil?

Is the bike horizontal?

How much oil are you putting in there?

[Ecarta]

Oil was checked about an hour after a modest ride..

Yes bike was horizontal. I put 750ccs in but only 650 came out.

[Ecarta]

Yeah, I think thats the gearbox vent hose.

The airbox is completely clean that breather hose did not spew anything.

[doakley]

Not sure I would be concerned over a loss of 100cc of trans oil upon draining. A fair amount is held up in the clutch and clings to gears, dead spots in the cases, etc. FWIW and slightly off topic, I generally overfill mine anyway, helps it run just a tad cooler.

[SS109]

Not sure I would be concerned over a loss of 100cc of trans oil upon draining. A fair amount is held up in the clutch and clings to gears, dead spots in the cases, etc. FWIW and slightly off topic, I generally overfill mine anyway, helps it run just a tad cooler.

Completely agree and I also overfill with one full quart (946cc).

[bufftester]

Yeah, I always run a full quart as well, mostly because I hated ending up with 6 or 7 nearly empty bottles of oil sitting around lol