Oil pressure light on/ milky oil after rebuild

F

first time rebuild

Registered
Hello all, long time reader first time poster. need some advise on what to do about my oil pressure and a possible coolant leak
I'm rebuilding a 01 busa, replaced the cracked head after the bike sat for 2 years. this has been the order of operations. among other things, this is the shortened version

-took motor into a shop to have new head installed
-Installed motor back into bike, added 4 quarts of oil
-bike turned over and i let it idle for about 5 mins
-the oil was then very milky
-drained bad oil and added another 3.5 of fresh oil
this time the bike ran for about 5 mins before the oil pressure light came on and i shut it down.
now the oil looks less milky (pics attached)

I've read about condensation, and just needing to burn that off, but how do i know if I'm gunna wreck it or not by running it? I don't know how to diagnose it without possibly blowing up the motor.
this is my first time rebuilding a motor so its a steep learning curve. I appreciate any advise yall have.

20240804_175204.jpg
 
You’d have to have a pint of condensation for oil to turn that color. Are you changing filters too? They catch a lot of stuff and in this case I’d use 2-3 oil filters to catch and clean the impurities in the crankcase. Why did the oil light come on? ‘Oil’ too thin? It didn’t come on the first time when most of the water mix was present.

However, a head gasket may be blown or the new head has a crack or the block may be cracked. Could be the wrong head gasket? I’ve never taken an engine into a shop for a new head so I don’t know what your instructions to them were. A compression test or a leak down test should be next. Good luck.
 
WuzzaCBXRider said:
You’d have to have a pint of condensation for oil to turn that color. Are you changing filters too? They catch a lot of stuff and in this case I’d use 2-3 oil filters to catch and clean the impurities in the crankcase. Why did the oil light come on? ‘Oil’ too thin? It didn’t come on the first time when most of the water mix was present.

However, a head gasket may be blown or the new head has a crack or the block may be cracked. Could be the wrong head gasket? I’ve never taken an engine into a shop for a new head so I don’t know what your instructions to them were. A compression test or a leak down test should be next. Good luck.
Click to expand...
Appreciate the advise!
I'm not sure why the oil light is on now and not before. I'm using 10w-40 mobile motorcycle oil. they didn't have any filters in stock so needing to order one, ill have to add another 1 or 2 to the order.
this might be a dumb question, but if coolant was leaking into the engine, wouldn't I see the coolant levels drop? as is the reservoir has stayed the same level,
I'm dreading the thought of taking the motor back out after 3 months of putting it back in and getting it running lol
 
Yes but not very much. Unless it’s overheating or really warm the overflow tank’s capacity would pretty much stay level. Another problem with this is that your fiber clutch plates will absorb the coolant. May make them sticky. How much will it effect the clutch operation is?
 
WuzzaCBXRider said:
Yes but not very much. Unless it’s overheating or really warm the overflow tank’s capacity would pretty much stay level. Another problem with this is that your fiber clutch plates will absorb the coolant. May make them sticky. How much will it effect the clutch operation is?
Click to expand...
the clutch is in-operable. which is probably related to this issue. when i pull the clutch lever and put the bike into first while on a stand, the tire rolls. when releasing the clutch i can hear the engine bog down as if its fully in gear, but pulling the clutch does not release it. I bought the bike for 3k and am really trying to not go deep underwater with this build, id like to break even at least, but perhaps i was a little hopeful and naive with this project.
 
first time rebuild said:
the clutch is in-operable. which is probably related to this issue. when i pull the clutch lever and put the bike into first while on a stand, the tire rolls. when releasing the clutch i can hear the engine bog down as if its fully in gear, but pulling the clutch does not release it. I bought the bike for 3k and am really trying to not go deep underwater with this build, id like to break even at least, but perhaps i was a little hopeful and naive with this project.
Click to expand...

Sometimes the rear wheel will spin in neutral. Not a real indicator of somethings that’s wrong. A leak down or compression test should locate any gasket or sealing issue.
 
Stop running it, you DO have a bad head gasket/not sealed correctly, or cracked head or block.
Coolant is mixing into the oil.
That is Not condensation.
That coolant is washing the oil/lubrication off of everything, and causing excessive wear, you don't want to keep running the engine.
The clucth not working has nothing to do with it either, that is a seperate issue, and could have several causes.
The rear wheel slowly turning with the bike on a rear stand with the engine running is normal.
The clutch is pretty simple to correct, but not worth worrying about at this point, as you need to fix the engine first.
That engine has to come out and back apart.
If the shop put the head on, hopefully they torqued it to spec, and in the right sequence(which would not make it seal correctly if they did not).
But, a head almost always cracks from overheating, and I would suspect the block as well.
Other than incorrect assembly(torque and torque sequence) I would say the block was damaged originally as well, either cracked, or the deck/top surface warped(extreme heat).
It could have no visible damage either, as you will not see that coolant is coming between a cylinder sleeve and the block, or that there is a crack in a water jacket into an oil passage.
Regardless, out and apart it comes, there is no other way to fix that.

welcome to the org
 
Looks like Ethylene Glycol coolant in your oil window.

At this stage, best thing to do is take the entire motor apart, inspect, and rebuild it as necessary. Not something to do by yourself, should you not be proficient in a trade, with a lot of automotive aspects tied to it. With respect.

Either have a competent source do that for you, or perhaps find an ebay motor as a replacement. With the latter, you never know what you get.
 
sixpack577 said:
Stop running it, you DO have a bad head gasket/not sealed correctly, or cracked head or block.
Coolant is mixing into the oil.
That is Not condensation.
That coolant is washing the oil/lubrication off of everything, and causing excessive wear, you don't want to keep running the engine.
The clucth not working has nothing to do with it either, that is a seperate issue, and could have several causes.
The rear wheel slowly turning with the bike on a rear stand with the engine running is normal.
The clutch is pretty simple to correct, but not worth worrying about at this point, as you need to fix the engine first.
That engine has to come out and back apart.
If the shop put the head on, hopefully they torqued it to spec, and in the right sequence(which would not make it seal correctly if they did not).
But, a head almost always cracks from overheating, and I would suspect the block as well.
Other than incorrect assembly(torque and torque sequence) I would say the block was damaged originally as well, either cracked, or the deck/top surface warped(extreme heat).
It could have no visible damage either, as you will not see that coolant is coming between a cylinder sleeve and the block, or that there is a crack in a water jacket into an oil passage.
Regardless, out and apart it comes, there is no other way to fix that.

welcome to the org
Click to expand...
As well does the head you installed have a straight surface.
Where are you located?
 
338WM said:
Looks like Ethylene Glycol coolant in your oil window.

At this stage, best thing to do is take the entire motor apart, inspect, and rebuild it as necessary. Not something to do by yourself, should you not be proficient in a trade, with a lot of automotive aspects tied to it. With respect.

Either have a competent source do that for you, or perhaps find an ebay motor as a replacement. With the latter, you never know what you get.
Click to expand...
Appreciate the advise,
I believe that's what is is as well, I have pretty minimal experience with dismantling engines so that's definitely a concern of mine. not to mention all the tools required to do the job correctly. just trying to keep cost down, i don't think the bike is worth much more than 5k running.
 
first time rebuild said:
Im in MN, I bought a used head on ebay and took it to a shop to mill down the 2 mating surfaces and install the head. Im geussing they did shotty work on it.
Click to expand...

Not nesacerily that they did bad work.
The head may or may not have been installed correctly, and/or you may just have had a bad block since the original head went bad.
 
first time rebuild said:
Im in MN, I bought a used head on ebay and took it to a shop to mill down the 2 mating surfaces and install the head. Im geussing they did shotty work on it.
Click to expand...
If the machine shop surfacing machine produces a more coarse finish on the gasket surface then those coarse finishes do not work well with MLS (multi layer steel) head gaskets. The coarse finish will work fine with a composite type gasket. MLS Gaskets require a very smooth finish or coolant with seep past the coarse finish.

Older machines that have a slow turning head with multiple carbide cutters usually do not leave a smooth enough surface finish for MLS gaskets, although some get lucky. An MLS Gasket requires an almost mirror like finish usually done with a single cutter spinning fast.

MLS gaskets can handle a lot of cylinder pressure from power adders, but Composite gaskets are very forgiving of less than perfect surface finishes. I don’t know if a composite gasket is available for your application as I am not a motorcycle mechanic. Good luck!
 
60+ Busa Rider said:
If the machine shop surfacing machine produces a more coarse finish on the gasket surface then those coarse finishes do not work well with MLS (multi layer steel) head gaskets. The coarse finish will work fine with a composite type gasket. MLS Gaskets require a very smooth finish or coolant with seep past the coarse finish.

Older machines that have a slow turning head with multiple carbide cutters usually do not leave a smooth enough surface finish for MLS gaskets, although some get lucky. An MLS Gasket requires an almost mirror like finish usually done with a single cutter spinning fast.

MLS gaskets can handle a lot of cylinder pressure from power adders, but Composite gaskets are very forgiving of less than perfect surface finishes. I don’t know if a composite gasket is available for your application as I am not a motorcycle mechanic. Good luck!
Click to expand...

Maybe not a motorcycle mechanic, but might have worked in a machine shop for a little while...
lol
 
sixpack577 said:
Maybe not a motorcycle mechanic, but might have worked in a machine shop for a little while...
lol
Click to expand...
Lol… I actually own one the older machines, mines a Storm Vulcan Head Master with 16 carbide cutter tips, it makes a very nice cut but just not quite smooth enough for MLS.
 
Every toolbox ought to have (assuming you have access to an air compressor) a set of these! you can learn just about everything you need to know about the state of the top end of an engine without a tear down. You can diagnose bad head gaskets, valves, rings, cracked head etc, you can even change valves springs and seals with the head on if you are careful, and all you have to do is listen at the appropriate opening. Set the cylinder to TDC, pressurize and listen to the adjacent cylinders, intake, exhaust, rad cap, breather etc. to know where the Air is going. Another Variant.
 
Just regarding the oil pressure light on . . first thing to do is check the wire connection to the oil pressure switch is secure and tight, if so, then check the oil pressure switch itself is working correctly.
Alternatively, test the oil pressure with a gauge and hose screwed into the oil gallery after removing the gallery plug and fitting the gauge hose into it.
The other obvious problem of coolant in the oil has already been discussed in the posts above . . my approach would be to pressurize the cooling system to 15psi and see if the pressure falls away. A warmed up engine is best, but if you are weary about running the engine, a cold test is ok.
Also, a leak down test would be a good idea, open the radiator cap and look for pressure bubbles coming up to the top.
 
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