Topic: How Blocked Up Was Your Oil Pump ?

[jaytee-nz]

Been stripping the engine on a CB500 "parts bike" and it sure isn't pretty inside. I don't think it has ever had an oil change as everything is coated in a thick oily sludge, including the oil pump !

[Tracksnblades1]

Probably a Non-Detergent oil engine..?  Non Detergent oils were used in old splash lubricated and/ or no oil filter engines. It was important that the contaminants immediately sank to the bottom and remained there as sludge to prevent being recirculated over and over because of no filter to trap them..

Then came full pressurized (oil pump) and filtered lubrication. High detergent oils were /are used to keep contaminants in a suspension while they travel to the oil filter to be removed..High Detergent oils have anti foaming additives that control foaming better than non-detergent oils..

Look what Honda recommended and what they warned you not to use…😇

[jaytee-nz]

No way to tell anything about the oil that was used as there was no oil in it - just thick sludge in the oil pan and other places in the bottom of the engine.
The camshaft is absolute toast, but the rest of the engine doesn't look too bad at a first glance. Need to properly check it though.

[Tracksnblades1]

No way to tell anything about the oil that was used as there was no oil in it - just thick sludge in the oil pan and other places in the bottom of the engine.
The camshaft is absolute toast, but the rest of the engine doesn't look too bad at a first glance. Need to properly check it though.

Camshaft was toast too..? 🤔

Are you thinking oil wasn’t up to the task..?
Or was it ran with no oil..?

[jaytee-nz]

I'd say low oil and / or no oil to the top end, because the bottom doesn't look oil starved.

[Don R]

 It looks like it got some water in it or maybe someone packed the pump with Vaseline trying to get oil pressure.

[jaytee-nz]

No water in it Don. The shine of the oil / sludge makes it look brown in the photo but it's jet black.

[HondaMan]

It looks like it got some water in it or maybe someone packed the pump with Vaseline trying to get oil pressure.

But, missed the pump gears?

I haven't seen one that bad before.

[Oddjob]

Don’t forget to remove and check the pressure relief valve as well. I did a test once on the pressure relief valve in the filter bolt. Out of 6 filter bolts tested only one worked, the rest were jammed in position. Out of 3 oil pump relief valves tested 2 were sticking in operation, most people fail to test they work and that can be fatal for an engine.

On aftermarket filter bolts some were manufactured with the relief valve wrongly fitted. Upside down iirc.

[Don R]

 Whatever the explanation is, that's one gnarly looking pump. yuk.

[jaytee-nz]

Yep, the oil pump is representative of the whole engine really. The reason I stripped it was to assess if it was worth re-building after I freed the seized pistons, so I will need go through and check / measure everything before making a decision on it.
Just cleaning the sludge off the cases will take many days of work.