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!
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.
Hiya, thanks for taking the time to reply. I bought the bike last April and it had just been fully serviced, including the cam belt. I rode it May til November and then it was put away, it probably hasn't done more than 1000 miles since I got it. This year it's done 20 miles but was regularly started. I hadn't checked the coolant tbh, it just needs a top up. Looks like a right awkward thing to get to but it's on my To Do list. I can't afford to take it to a garage, so I have to do the work myself. I did a level 3 bike mechanics at college so I'm confident enough to dive into tasks, I lack the testing equipment though. I've not really worked on fuel injected bikes before or this type of engine (other than at college but that was 3 years ago), so any pointers are definitely appreciated. I need to get the tank off and learn this bikes components and locations, thankfully I have the s4 manual now and found the owners booklet. So my job today is to take the spark plugs out and check those, I fully expect them to be wet. Mentally, I'm going through a checklist of how this can happen. Just checking the mot history online, it was 10,229 in March 2023 and 10,874 in July 2024 - well that's embarrassing! Has to be rectified asap. I have a strong suspicion that it's the piston rings either worn or not correctly aligned, I'd really like to be wrong about that. I have a lot to work through. Cheers for your help.
Update: I can't believe it was October, not sure how 6 months blasted by, but there you go. I couldn't get the oil filter off. Tried everything, lots of different tools, it was seized on. Yesterday, I finally got it on the skylift (another saga) and was able to get the band tool back on it and give it some serious effort. It was a Ducati one, I've replaced it with a K&N racing one to stop that f*ckery occurring again. Today, with assistance, I finally got the fuel tank off. The hoses were really short and there was very little room to get in there. I've replaced the bleed hoses as they were perished. It looks like the filler cap o-ring has been glued on, so not sure how to get that off without taking the paint with it. We decided to investigate the fuel injectors. There was a lot of swearing. Then some more. Who decided to have that many bolts, in that many places for the air box base? Huh! I take it the injectors have a special tool to lift them out? I've watched some YT vids and they pop off.. mine don't. I have removed the wire clip and bracket. They turn, but they will not come out and I don't want to damage the tops with pliers. I wanted to clean the injectors and test them. I don't want to sound stupid, but wtf are the spark plugs located on these lumps? The owners manual mentions maintenance but no pictures. The Haynes manual is pants. I've googled it, searched YT for how-to vids and actual S4 manuals. I've always managed to find information on the bikes I've worked on but this is sparse. I'm going to dive back into this forum and see what I can find but if there's any particular threads/links you can suggest, please please please let me know. I have also found a connector off the ecu, that I don't know where it goes. There's a 2nd earth cable from the crank case but there's already one connected to the battery. It looks clean and it doesn't look like it was connected anywhere (L bracket) - any ideas? Whilst I have an IMI3 in bike mechanics, and built my own bikes in the past, I've not had this kind of bike before or fuel injected, so your help is greatly appreciated - thanks.
OK There are waaaaay better spanner folks here than I am -or ever going to be- and I'm sure they will be along soon. Re your spark plugs, this vid should hopefully sort that out for you. I find that taking pics of the problem can sometimes help others to tell me what I need to do. I imagine a pic, showing the wire that is not connected to the ECU could help resolve that? You are in the right place to get help, and with forum knowledge and your confidence I expect (with a little more swearing) and some luck you will be back on the road soon.
Cheers for that. The S4 has a 916 engine in, so looks different to this one BUT it gives me a place to start looking. I was looking for coils, forgot about those types. I've mainly worked on Suzuki carbed bikes, so getting my head out of inline 4 mode and into these, is taking some learning. I have the haynes for the 916 but the pics are rubbish and I'm the sort that needs to see it properly in relation to the rest of the bike, for it to sink in, so vids are great. I'm currently going through parts fiches to see what parts are what. The cable and connector is off the ecu, I'm about to go hunting for a wiring diagram to see what it does, it's not listed on the parts fiche seperately.
https://oem-bike-parts.com/en/parts/ducati/2002/s4/wiring-harness-wiring-harness It's the connector above no.15 edit: I think it's a diagnostic port....
Not watched the YT clip but title says S4, they are a 916 motor as standard aren’t they? Or are some a 996? I have the RS and it’s a 998
The later models had bigger engines apparently. Mine doesn't have that lower cooler. Wish mine had the belly pan and side panel... *must not side quest* basically it's this one https://www.autoevolution.com/moto/ducati-monster-s4-2000.html#aeng_ducati-monster-s4-2000-916
So plugs etc should all be same place and stuff. It’s same engine just less displacement. And I’d expect most parts (all parts outside engine internals) to be interchangeable
I had an S4 till ii wrote it off. The coils are the spark plug caps I have a 916 sp that was massively overfuelling. Without going through everything it turned out to be the last sensor I changed. The air temperature sensor. When I tested it had a very high resistance. (The colder the air the higher the resistance) the ecu thought i was riding round the Arctic so pumped fuel to suit i was emptying the tank in 60 miles. The air temp sensor should you need one is Magnetti marelli 219244250500. They were fitted to many cars of the same era and are readily available ( cheaper than 2nd hand ones from e Bay seller) .
If it were mine, I’d change the oil, fill to the correct level. Change the coolant, fill to the correct level. Fit new spark plugs of the correct grade. check the condition of the belts and their tension. check the condition of the air filter, replace if needs be. check someone hasn’t stupidly routed the fuel overflow pipe into the air box. Fill with fresh fuel and ride it. You never know what went on whilst it was in the hands of previous owners. Never accept as gospel what you’ve been told. Give it a service and at least you have a known base point to work from. Keep an eye on things from there on.
Thanks y'all That's the plan. Belts are good, inspected them yesterday. When I can find the coils/sparks, I'll measure and replace if they need it. Got fresh oil ready to go in and new filter fitted. Air filter is good, no wrong pipes into air box. Changed 2 of the sensors (square ones next to ecu) under advisement. Seen that trick about getting the injectors out, so once I do, will clean/test them too. Gives me a good chance to learn more about the bike and I need a hoon so bad, it's killing me hearing everyone out. It's a 24 year old bike now, she needs some tlc. Love this site but I'm blocked on it now, going on their fb page, this has been an issue for 2 years now. I think it's folded. I have the physical 916 haynes manual and the s4 owners booklet but if anyone has a s4/monster haynes/workshop one, I'd really appreciate that. Awesome, looking into that now. It has stunk of fuel for ages, thought it might be a vent issue but as it ran well, didn't look into it further. I think it's been overfuelling enough to stink up the oil but not enough to fill the engine with fuel.
Those sound suspiciously like relays to me rather than sensors. Message me your email address and I’ll transfer the workshop manual via WeTransfer or Dropbox. The plugs are under the coil sticks in each head. The coil sticks can be a bugger to get out as they stick to the plug and the wall of the well they are inserted into, plus a vacuum builds up. If a PO greased them they’ll come out relatively easily if not prepare for a battle. The correct plugs are NGK DCR9EIX (NGK code 6650). They have a 16mm hex nut and you’ll need a thin wall spark plug spanner to get down to them.
The amount of fuel injected is determined by the TPS opening and engine revs modified by the air temperature and coolant temperature sensors. Most likely one of these sensors is faulty but it would do no harm to do a TPS reset first. This is a mechanical procedure on these models not a software reset. TPS set up here . Melcodiag should help diagnose any sensor issues.
Cheers. My bad, I meant relays, it had been a long day. I can't believe I forgot about stick coils, I'm so used to the old sort with leads. I have located, removed them (without any issues) and the spark plugs. The plugs were wet with fuel and the electrodes were very thin and the gap way out of range - so needs a new set. How come you can only get iridium ones for this bike? Curious. I'm more determined than ever to get those injectors off, I'm hoping that they just need a clean. I'm not sure as a noob that I can message you yet but a proper workshop manual would be fab, the 916 manual isn't very helpful and the owners one is no use either. ([email protected] I can always edit this after.) Cheers. That's really helpful. I've had a look around the bike today and noted where the sender intake air sensor (Magnetti marelli 219244250500) is and need to identify the others and locations. Is the throttle body going to have to come off for this? I watched it being done, not looking forward to that. I'll check out those links now. Thanks everyone x
Had a read. Had a Google for parts.. it's a mine field out there. Does anyone have a trusted retailer please? Thanks x
