Filthy engine
 

Hi,

Got a new (well, 2nd hand '99) engine transplanted into my SV just before Christmas (with help from YC). It's been running OKish (still need to get around to balancing the carbs) but I think it's fair to say that the inside of the engine could probably be in a bit of a better state.

Took the first lot of new oil out after 200-300 miles and it was as black as sin (the bad kind of sin, not the good kind :D). Slapped new stuff in and 200-300 miles later it's black, gooey and just about as sinful. Even with my poor level of mechanical knowledge, I know that's not a good thing. There's a few tiny bits of rust/metal in there too - which isn't good.

The engine seems to be running ok regardless though (except for chugging a little trying to turn itself in a dark, thick, goopy oil soup), so I'm kinda hoping that a few oil changes down the line I'll be just fine and it's just the matter of running in an old, disused-for-some-time engine.

Has anyone experienced this before, and either way, has anyone any suggestions as to ways to get the insides cleaned out other than pouring gallons and gallons of new oil into the thing every couple of hundred miles?

Adrian

Re: Filthy engine
 

Any engine - with the possible exception of an absolutely brand spanking new one - will turn the oil black as soon as you fire it up after doing an oil change.
This is completely normal, engine oil is wedged full of detergents cleaning agents, and is intended to hold in suspension the sort of stuff that causes the oil to turn black, this is a good thing - when you change the oil that stuff comes out. It's mostly carbon products of incomplete combustion that gets into the engine's bottom end as a result of ring blow-by.
Pouring gallons of oil through your motor won't stop it happening as you can never get all the oil out, (well, you could strip and thoroughly clean the engine internals I suppose...), because there are some nooks and crannies inside the engine that will always hold some of the old oil, and this will colour the new oil as soon as you start the engine.

I very much doubt there's anything wrong, with the obvious exception of your letting that spanner monkey Chris loose on your bike - that's something to worry about :D

Re: Filthy engine
 

[QUOTE=Vindaloo;2229546]Hi,

chugging a little
Not running rich is it?
That wouldn't help.

Re: Filthy engine
 

Hmm. I know it's going to inevitably be darker once it's in the engine, but I don't remember it ever showing up this dark in the sight glass - or seeing the old oil being as dark as the stuff I removed last time (can show a pic, but it's probably a little subjective on camera). The tiny bits of metal in the old oil is probably the biggest warning sign for me.

As for the chugging, well I think that's part-due to the carbs needing balancing. It's actually running a little lean, if anything.

I'll give it another oil change now and see what happens, I suppose. Just wondered if there were any products anyone could recommend to give the insides a clean out.

Cheers guys,

Adrian

Re: Filthy engine
 

You can flush the engine clean wth engine oil :D Use something a little cheaper, but still decent, like halfords motorcycle oil. Fill up as per normal, got for a ride (maybe 10 miles or 30 mins) then when you get back, drain the halfords oil, refill with something proper good (maybe change the oil filter too actually) like castrol or motul.

Oil that looks dirty shows that its doing its job, its suspending dirt and keeping it from clogging up oil galleys etc etc. So long as there arn't metal shards or whatever in the oil, then thats pretty much ok

Re: Filthy engine
 

Make doubly sure the chokes aren't sticking, this will produce loads of carbon (ref Sid's post) and will turn the oil black very quickly. Also you might well notice a smell of fuel in the oil if this is the case.

Re: Filthy engine
 

that dont sound good :S

Re: Filthy engine
 

I'll throw some cheap oil and a new filter at it tonight if I get time then and see how things go over the next 1-200 miles.

Adrian

Re: Filthy engine
 

I've stuck cans of oil flush treatment through hundreds of car engines before. I assume they'll be ok in a bike, may help clearing some stuff out.

Re: Filthy engine
 

The bits of metal don't sound good.

I've got a can of engine flush here that's yours if you want to give it a go.