Saluti! I mentioned in my intro post about some issues I'm having with my S4 2001 and could do with some help please. I spoke to the former owner today and he suggested some things to do, but can't work out how or why this has happened. Whilst I have experience with carbed bikes, I'm not very familiar with fuel injection but I have a basic understanding of the working principles. The problem: engine oil stinks of petrol, can't work out why or how though. My Bandit use do this but with the absence of a fuel tap and carbs, that can't be the issue here. Bike was well maintained. Oil sight glass was full, wasn't previously. Dropped the oil and it stinks of petrol BUT when I measured it out, it's 3.5L, which is the capacity (plus oil filter extra). I need to get the oil filter off and see if there's a lot more. There is still fuel in the petrol tank, probably enough for 'reserve'. I only use super unleaded. The fuel pump does prime when you start the ignition. The bike was running well, there always has been a whiff of petrol though but couldn't locate a leak and the bike ran well. I put it down to a breather tube in the filler cap. I have regularly started it up and kept the battery charged, when not in use. It didn't get ridden until July when I took it for the MOT, which it passed without issue. It ran fine but a bit boggy like when the fuel is running out. I went to take it out in August and it ran but then kept cutting out, then wouldn't run at all. Battery was fully charged, pump was working, it was cranking. When I was doing a check, I thought I'd check the oil and out of habit (it's a bandit thing), sniffed the oil cap and realised there was fuel in the engine. I have also noticed that the coolant res is under the min mark. I haven't check the rad yet. Possibilities... questions... The bike is running too rich? I need to check the sparkplugs next. Excess fuel typically gets fired out the exhaust valves.. right? It shouldn't end up in the engine unless the piston rings are worn... yeah? Could the choke be stuck open on the injectors? Is that why it's running rich? Judging on the amount of oil, I don't think that there can be that much fuel in it but enough for it to smell. If the coolant had leaked through the water jacket/head gasket, the oil would be salad cream, right? I will check the radiator for tell tale signs of blown head gasket and top up the res. When I was under the bike, I noticed that there was a leak, which wasn't there before. I think this is from where it's overfull. It looks like it's seeping from along the clutch cover gasket, I've degreased the area and will check again. Any ideas what could have caused this and how to cure it? Thanks in advance Chao!
Hi, firstly top up your coolant. - Yes, if it was a head gasket and you'd had a coolant leak then you'd see it in the oil, and your temperature would go sky high. Are you saying that the coolant was just low, or that it had gone down since you last topped it up? Without you going down a lengthy rabbit hole, when was it last serviced? - and I'm not talking about belts done, but a proper service where it was given a decent once over? Are the fuel and air filters are all good? Have you checked the pugs to see if one cylinder is more affected than the other? - it will give you a clue if one of the cylinders is misbehaving. I'd start by making sure that everything is as it should be. On the basis and assumption that perhaps one of the plugs or both looks like it's sopping in fuel, highly likely if you're seeing it in your sump, then you might want to check or get checked the CO levels, throttle bodies and the injectors int he first instance before you go down the checking sensors rabbit hole. If the CO levels on the throttle bodies are out, then it has the potential to fuel heavily and cut out if the air fuel ratio isn't right. Doing this will also give you a chance to check the state of the injectors and see if they're sticking or not, and the throttle bodies balanced up. The mechanic will also be able to check the TPS for you - something which on your bike isn't as easy as plugging in and pressing the TPS reset. Getting these out of the way and verified should then allow you to start trouble shooting other things as you know that the gas test was within spec, and your injectors are in good health and your throttle bodies are synced and tps working as it should, before going down the rabbit hole of testing and trouble shooting sensors and all that stuff. At least your bike didn't try to do that thing where it decides to jumpstart itself on the next revolution and lock up the back wheel in an attempt to spit you off, so you're winning already.
If it is massively overfueling it can wash the bores and get into the oil (petrol is far thinner than oil and will get past the rings). If the engine is run like this it causes wear quickly so needs to be avoided. As said above it needs a proper service/ investigation to determine what’s wrong. Hopefully something simple.
