Topic: 750 oil tank flushing

[my name is nobody]

During recent tear down, to check transmission issue, I found lint like material in oil pump screen, covering about 2/3 of the screen. To be safe, I tore the engine down and cleaned everything and hopefully found
the transmission issue aswell. The lint material didn't appear to have gone past the screen thankfully.
I am now at the stage of flushing the oil tank of contaminates, if there are any, and need to know if there
are any special steps to do so. Never seen the inside construction of the tank.

 ( Lint like material believed to be
from shop towels used during previous tear down. Thought it might be clutch fibers, but saw no evidence of
it any place other than the oil pump screen, and frictions look evenly worn, but at low end of allowable spec.
Gonna try things again and watch for problems.)  thx..

[Terry in Australia]

Good job, it's amazing what you'll find in an oil tank, especially after an engine explodes. The last one I did for another guy was full of clutch fibres, and had blocked the oil lines, but another one I bought with a pile of CB750 stuff was full of 'Roo poo! Obviously someone had a problem with the owner, it's a pity you can't buy locking oil tank caps!

If you really wanted to flush it out completely, I reckon dropping it in a tub of simple green overnight would be a good start. I degreased mine on my K2 and saw a little surface rust in there too, so I put it in a bath of phosphoric acid for a few days, and it came out as clean as a whistle.

[ekpent]

 I put a cork plug in the fittings and washed my last one out with some clean old gasoline that I saved from draining a gas tank. Best to do outdoors though weather permitting.

[PeWe]

I have had thoughts about the oil tank and its oil flow direct to the pump passing NO filter at all.
Sand, rust flakes will go direct to the pump and wear the pump, going further to oil filter and hopefully stay there before it can harm anything else.
http://www.hondachopper.com/garage/oil_flow_diagram/oil_flow_diagram_lg.html

If cam bearings are out of oil the problem must be AFTER the oil filter, right? Or if the spring pressing the oil filter tight against case is forgotten. I always make sure that no sand or dirt will enter the oil filter area when replacing it. Good idea to wash engine before removal of oil filter.

I have an oil tank that has been glass beaded. It has small particles inside I need to flush out. I have another tank that need to get a vinegar treatment just for sure.

[my name is nobody]

I have had thoughts about the oil tank and its oil flow direct to the pump passing NO filter at all.
Sand, rust flakes will go direct to the pump and wear the pump, going further to oil filter and hopefully stay there before it can harm anything else.
http://www.hondachopper.com/garage/oil_flow_diagram/oil_flow_diagram_lg.html

If cam bearings are out of oil the problem must be AFTER the oil filter, right? Or if the spring pressing the oil filter tight against case is forgotten. I always make sure that no sand or dirt will enter the oil filter area when replacing it. Good idea to wash engine before removal of oil filter.

I have an oil tank that has been glass beaded. It has small particles inside I need to flush out. I have another tank that need to get a vinegar treatment just for sure.

That sounds correct. I never studied it before, but the pump looks unprotected on the tank side  if
I'm reading it right. I wish I
knew for sure what the material found in the screen was for absolute certain. I 've seen threads about it here, but no definite
answers as to what it was or what causes it. Just knew that the tank was part of the system and needed
to be clean just like the rest of the system.

[PeWe]

Mtrl I have found in screen (correct side) has been rubber parts from tensioners, sealer used for cases and parts from a broken clutch.
All dirt and metal shavings etc from head where oil splash around, gearbox, clutch will hopefully end up in oil pan and stay there ready to be follow oil at oil change or the pan removal with cleaning it and strainer. Interesting clean at around 1000km after total engine restore.
Honda specify regular cleaning of the strainer.
Maybe I'll open the pan every 10.000 km or so to see the engine status. It should be clean here.

If using too long M6 bolt when tighten the engine side covers, the alu bottom will plop really easy and hopefully be flushed to the pan really quick. I was happy to find one bottom without cracking gear inside..I have not noticed any harder parts.

[my name is nobody]

Good job, it's amazing what you'll find in an oil tank, especially after an engine explodes. The last one I did for another guy was full of clutch fibres, and had blocked the oil lines, but another one I bought with a pile of CB750 stuff was full of 'Roo poo! Obviously someone had a problem with the owner, it's a pity you can't buy locking oil tank caps!

If you really wanted to flush it out completely, I reckon dropping it in a tub of simple green overnight would be a good start. I degreased mine on my K2 and saw a little surface rust in there too, so I put it in a bath of phosphoric acid for a few days, and it came out as clean as a whistle.

Thanks Terry, I think I'll go with that. It's the most practical for my situation as far as cleaning stuff goes.
Can't do anything outside, as its 5 degrees F., and simple green can be used indoors and covered while
soaking. I guess there's nothing inside the tank that requires special attention(?)

Mtrl I have found in screen (correct side) has been rubber parts from tensioners, sealer used for cases and parts from a broken clutch.
All dirt and metal shavings etc from head where oil splash around, gearbox, clutch will hopefully end up in oil pan and stay there ready to be follow oil at oil change or the pan removal with cleaning it and strainer. Interesting clean at around 1000km after total engine restore.
Honda specify regular cleaning of the strainer.
Maybe I'll open the pan every 10.000 km or so to see the engine status. It should be clean here.

If using too long M6 bolt when tighten the engine side covers, the alu bottom will plop really easy and hopefully be flushed to the pan really quick. I was happy to find one bottom without cracking gear inside..I have not noticed any harder parts.

Good to know, thanks PeWe

[Terry in Australia]

Good job, it's amazing what you'll find in an oil tank, especially after an engine explodes. The last one I did for another guy was full of clutch fibres, and had blocked the oil lines, but another one I bought with a pile of CB750 stuff was full of 'Roo poo! Obviously someone had a problem with the owner, it's a pity you can't buy locking oil tank caps!

If you really wanted to flush it out completely, I reckon dropping it in a tub of simple green overnight would be a good start. I degreased mine on my K2 and saw a little surface rust in there too, so I put it in a bath of phosphoric acid for a few days, and it came out as clean as a whistle.

Thanks Terry, I think I'll go with that. It's the most practical for my situation as far as cleaning stuff goes.
Can't do anything outside, as its 5 degrees F., and simple green can be used indoors and covered while
soaking. I guess there's nothing inside the tank that requires special attention(?)

Mtrl I have found in screen (correct side) has been rubber parts from tensioners, sealer used for cases and parts from a broken clutch.
All dirt and metal shavings etc from head where oil splash around, gearbox, clutch will hopefully end up in oil pan and stay there ready to be follow oil at oil change or the pan removal with cleaning it and strainer. Interesting clean at around 1000km after total engine restore.
Honda specify regular cleaning of the strainer.
Maybe I'll open the pan every 10.000 km or so to see the engine status. It should be clean here.

If using too long M6 bolt when tighten the engine side covers, the alu bottom will plop really easy and hopefully be flushed to the pan really quick. I was happy to find one bottom without cracking gear inside..I have not noticed any harder parts.

Good to know, thanks PeWe

No worries mate, the Simple Green is just concentrated detergent, so won't harm anything in your oil tank, just give it a good flushing with clean water, and considering your current weather, poke a hair dryer or heat gun inside to dry it out completely before use. Cheers, Terry.

[disco]

The inside of the oil tank has a short pipe that elevates the oil draw off point approximately 1/2” or so.
Have a probe around with a welding rod or piece of wire in this area. I found on one of my 750’s there was a lot of crud accumulated in the bottom of the tank that never gets drained off during an oil change.
I removed the oil tank & using the rod, busted up the crud and then flushed it out.

[Don R]

 I've used brakeclean and a shop vac with a piece of copper tube for a nozzle. Mythbusters proved the vac won't turn into a jet engine or blow up.