Hi All,
I recently rebuilt a 525 (entire engine - top and bottom ends) and apart from the carburetor possibly needing some fine tuning and (my current problem) Aerated/Foamy oil, it seems to run ok.
I'm worried about the amount of air in the oil during running. I read online that this could severely impact your oil's life (degrade prematurely) and lubrication effects (engine running inefficiently and thus probably hotter than normal with more parts wear). Before a start, I check the oil. No signs of water in the oil and its clear and clean (see pic: oil-before-start). Directly after a start (immediately) the oil goes foamy/aerated (see pic: oil-during-running).
I don't want to ride with it because I don't want to bugger up the engine and I would rather find the source of the problem and fix it than run it with the aerated oil.
What I've done so far:
1. Check the head gasket for tell tail signs of it being blown (during running).
a. No bubbles in the radiator (I guess I would see that immediately)
b. Hold a tissue at the exhaust to test for moisture. Nothing!
c. I don't notice any "water usage"- levels remain as is.
2. Removed some oil from the sump (in case I overfilled it). Just at the bottom part of the oil glass.
3. Removed the engine breather pipe connected to the carburetor and let it run into the atmosphere.
4. All jets were cleaned out during the re-build and locktight and torqued to spec (as per the spec). There should be no obstruction on these jets (crank cases jets)
None of these solve the issue and I still notice significant air in the oil immediately when I start it.
Since I'm trying to fix this engine on a budget - I know of some possible issues. I'm not sure which of these may result in air in the oil...
1. The barrel has minor scrapes from the piston skirt (see pic: barrel-scrapemarks). You don't feel this other than a bit of roughness on the barrel. So nothing deep which could result in blow-by (I don't think so?)
2. The cam chain tensioner is fine, even though I had to fix the thread with a heli-coil to get it to torque to spec. I'm sure that should not have an effect on it. Even if there were some slap... its on the side of the motor. I don't think that would result in this amount of air in the oil?
3. A crack on the crank shaft was welded with a previous re-build (see pic: crank-weld). It seems to hold ok...
4. I did not open and clean out the carburetor (I guess I should have ... but I didn't want to mess with that - yet)
5. I ran out of 4T Liqi Moly and could only get 4T Motorex (around 200ml) (all 10W50) but mixed???
I just filled it with oil... do you need to "bleed" a new engine when filling with oil?
Next I plan to drain the oil and refill with one tipe of oil - 1.2 L. Other than that... I don't know...
Do the experts maybe know if this is normal? or if not, what could cause it and what is a possible solution?
Thanks all!
I recently rebuilt a 525 (entire engine - top and bottom ends) and apart from the carburetor possibly needing some fine tuning and (my current problem) Aerated/Foamy oil, it seems to run ok.
I'm worried about the amount of air in the oil during running. I read online that this could severely impact your oil's life (degrade prematurely) and lubrication effects (engine running inefficiently and thus probably hotter than normal with more parts wear). Before a start, I check the oil. No signs of water in the oil and its clear and clean (see pic: oil-before-start). Directly after a start (immediately) the oil goes foamy/aerated (see pic: oil-during-running).
I don't want to ride with it because I don't want to bugger up the engine and I would rather find the source of the problem and fix it than run it with the aerated oil.
What I've done so far:
1. Check the head gasket for tell tail signs of it being blown (during running).
a. No bubbles in the radiator (I guess I would see that immediately)
b. Hold a tissue at the exhaust to test for moisture. Nothing!
c. I don't notice any "water usage"- levels remain as is.
2. Removed some oil from the sump (in case I overfilled it). Just at the bottom part of the oil glass.
3. Removed the engine breather pipe connected to the carburetor and let it run into the atmosphere.
4. All jets were cleaned out during the re-build and locktight and torqued to spec (as per the spec). There should be no obstruction on these jets (crank cases jets)
None of these solve the issue and I still notice significant air in the oil immediately when I start it.
Since I'm trying to fix this engine on a budget - I know of some possible issues. I'm not sure which of these may result in air in the oil...
1. The barrel has minor scrapes from the piston skirt (see pic: barrel-scrapemarks). You don't feel this other than a bit of roughness on the barrel. So nothing deep which could result in blow-by (I don't think so?)
2. The cam chain tensioner is fine, even though I had to fix the thread with a heli-coil to get it to torque to spec. I'm sure that should not have an effect on it. Even if there were some slap... its on the side of the motor. I don't think that would result in this amount of air in the oil?
3. A crack on the crank shaft was welded with a previous re-build (see pic: crank-weld). It seems to hold ok...
4. I did not open and clean out the carburetor (I guess I should have ... but I didn't want to mess with that - yet)
5. I ran out of 4T Liqi Moly and could only get 4T Motorex (around 200ml) (all 10W50) but mixed???
I just filled it with oil... do you need to "bleed" a new engine when filling with oil?
Next I plan to drain the oil and refill with one tipe of oil - 1.2 L. Other than that... I don't know...
Do the experts maybe know if this is normal? or if not, what could cause it and what is a possible solution?
Thanks all!
