Engine/oil flush.

[gareth]

Let me apologize in advance for asking this in the XS forum, but I figure the information might be relevant to some XS new owners too..

I picked up an FJ1100 that has been sitting for a long time. There is oil in the crankcase, but the oil level is low and the stuff is thick and black. My first instinct is to just fill the crankcase up with kerosene or something and let it sit for a while, slowly crank the bike through a high gear a couple of times, and then drain and refil with cheap oil while I ready the bike for a proper "starting".
When I go on the web and research "oil flush", there seems to be conflicting advice about any kind of solvents in the crankcase and the whole "oil flush" thing seems to have a few opponents...

What have others done to get the gunk out of old bikes before the first starting attempt?

Similar questions about hydraulic/ master cylinder fluids are bothering me too..

Any advice would be much appreciated.

Gareth.

[prometheus578]

Ideally, one could drain the oil, and then drop the oil pan and scrape out the gunk.
Chances are, it's not that bad.
Now then... as allt ehc rap is settled to the bottom, I see no need to fire the bike up and pump that stuff up into the head where it'll sit in all the little recesses.
If you want to play... I'd say drain the oil and then fill the crank with the kerosine and let it sit for a few days.
Drain everything, fill with clean, but cheap, oil and fire it up to temp.
Ride it a bit maybe and then drain and refill with good stuff.

[Bonz]

That seems like a pretty good idea.

The negatives to the "Gunk" type oil flushes are they can (and did on a 4.0L Jeep Cherokee I put it in with high miles "just to do it) make older, dry gaskets start to leak. My logic said the gasket becomes a wick for the thinned out oil and I never could get it to stop.

Don't know if kerosene has the same tendencies, or if the Gunk flush has other "ingredients" that lead to the gasket leaking.

If it's not hard to drop the pan, do it and you'll get all the stuff out and there will be no potential for old oil or the by-products of old oil that has been thinned to get where you don't want it.

Then put in the prescribed cheap oil, run it a bit (don't know why you couldn't ride it) and then drain it out and fill with good oil. Just my $.02 if I was doing it.

[HobbyMan]

Every time I get a new bike, I drain the oil and flush gasoline through the oil pan and change the filter. Then I put regualr 20w50 in it. I do not run very far on that oil. After a few hundred miles, I change the oil and its back on the regular schedual.

[prometheus578]

"HobbyMan... Nice of you to drop in!"

We know how busy you are with your school schedule, and all those demanding Merchant Marine classes....

[eroellig]

Well, when I got my bike, I didn't need to worry about adding in a special "flush". Between the gas leaking out of the carbs (before rebuilding them) and all the blaster penetrating oil I squirted in to break the rings loose, there was more than enough solvent in the oil. When I changed it (before firing it up for the first time after restoration), that s^%$ stank like nothing else I've experienced.

Eric

[Crazcnuk]

If I deem it necessary, I pull out the sparkplugs and rotate the engine until all 4 cylinders are close to level with wach other (mid stroke?)

I pour diesel fuel in the sparkplug holes until the cyclinder is full, then put the sparkplug in a few turns, just to keep crud out.

Let the bike sit at least overnight, preferably a few days, then start it, let it idle fo a few minutes (2-3) with NO load. If you have the back wheel off the groud, or off, you can go through the gears a couple times, while working the clutch.

Shut the bike (car) off, drain the oil, put in new oil and filter. Drive it for a couple of hundred kms, then change the oil as usual.

The diesel will clean most gunk, it is still a lubricant, so it won't run anything dry and putting it through the rings will often unstick any gummed up ones.

It's interesting to do a before and after compression test. I had a 1982 Midnight Maxim that went from 90psi across the board to 135-140psi doing this procedure. .

[wa407mpp]

Heads up!

In response to a question in the tech. Q&A section of the June Rider mag, Chris Sidah recommends Marvel Mystery Oil to flush dirty engines. That might be worth a try, but what ever you do, remember it might harm the clutch if you get carried away. In my experience, I've found it best to let sleeping dogs lie, and settle for a lot of oil and filter changes, because if you break a bunch of gunk loose some of it could plug some small and very important oil passages and cost you an engine.

[gareth]

Good stuff..

Thanks for all input.
I like the idea of a diesel flush and it's readily available at the corner garage now for the just-for-today price of $4.99 per gallon.
I already stuck a few ounces of Marvel Mystery in each pot. I pulled that one from the archives. I think since the bike has been sitting on the sidestand for ages, that I'll just drain the pan and pull it. I have a vision of a shallow triangular beach of black gunk, who knows how thick, settled on the left side of the pan that just won't get removed except by constant oil-change erosion.


I think I have to pull the 4-1 off anyway to get to the oil plug. Then do the fill with diesel thing suggested by Crazcnuk and go from there....
So here's hopin' the pan gasket will stay intact...

Thanks again,

Regards.

Gareth.

[Axel]

Seafoam

I use Seafoam in the oil for a 10-20minute period on the center stand . I use a fan to keep it cool . When it is down a half quart ,I add a full can of Seafoam and sit on it while running and go slowly through the gears . Then I drain it all out and add my new oil .

[TopCatGr58]

Hey Gareth,

IF the pan gasket gets torn up, you can easily make one yourself out of sheet gasket material, use a SINGLE hole punch to create the bolt holes..perfect size, and just scissors or an exacto knife to cut out the shape....just use either a rubber mallet to gently tap the pan pattern into the gasket, or others have put a thin film of oil on the pan, and then pressed it into the material, it makes a nice PRINT! Just remember, there is a section/bracket screwed into the pan that keeps it from laying flat, remove it first to make impression, then put it back in before reassembly!
T.C.

[jeffe]

I have also been using some Seafoam per directions just before each oil change. The first time I used it I was amazed at how much gunk it broke lose in the crankcase. It also seem to keep the clutch working smother. Since I have done this a few times the oil does not seem to be as dirty now when I change it. 20/50 Castrol is what I have always used.