Hi, looking for help regarding a non starting S4 Monster. Quick backstory.... I purchased the bike in August 2018 aware that it wouldn’t start due to a flat battery. It’s sat in my garage until the lockdown started so I finally took the opportunity of getting it back on the road. To date I have fitted a new battery, new cambelts, Fitted the exactfit starter motor cables and earth cable. New fuel tank petrol filter and all fluids and oil filter replaced. Iridium spark plugs fitted and gap increased as advised and there’s a nice big fat spark on both plugs. The engine turns over well and it attempts to fire with the occasional Pop and bang but refuses to run. Both exhaust headers get warm. I have noticed that the tacho needle does not move when the engine is being turned over and the code light does not flash when the ignition is turned off and black key removed. I have tried the second black key as well as the red key. Just wondering if it’s the immobiliser ? Thoughts/comments/advice greatly appreciated.
I don't know S4 quirks intimately but have you tried opening throttle a tiny crack/5 degrees while cranking?
If it was an immobiliser issue the engine wouldn't fire at all. More likely, as Chris suggests, an air/fuel ratio issue. Too much or too little throttle opening.
Is fuel getting in? I had an issue when my S4R would not start because the main fuel filter had never been replaced and was blocked. With no plug in and a few goes on the starter on full choke it should reek of petrol.
Hi Chris, I have tried using the throttle whilst cranking the engine and opening it when it fires but I will certainly give your suggestion a try in the morning
Hi Derek, I’ll take a look at the injectors tomorrow and will try various throttle positions whilst cranking the engine over. I was thinking immobiliser because the key code light does not flash in the tacho
Hi, it is getting fuel because it does attempt to fire and run and the plugs are wet when I remove and check them. It could be a partial blockage in the injectors due to lack of use so something to check tomorrow.
I’ll check the coils tomorrow morning but they are not something I have messed with since buying the bike, that’s not to say that they may have been altered in the past
I had an S4 Monster. The only problem I ever had was the horizontal coil breaking down. Having never needed to work on mine other than servicing I can't remember where items are located. I would find the coil/injector relay and change that.
Hi, thanks for your comments and I will check all of the connectors today. I checked and cleaned the crank position sensor connector and side stand switch connector yesterday, both had surface corrosion on the pins so cleaned them and used dielectric grease when reassembling. I’ll do the same with the other connectors today and hopefully upload a video of the starting problem later.
Does the S4 have a cold start lever? I used to have an ST4s and for the first few days of ownership I difficulty getting it to fire up from cold until I found that position of the cold start lever was critical. It wouldn't fire on a closed throttle, it wouldn't fire if the throttle was too far open or might fire but I couldn't catch it to keep it running. It wouldn't fire with cold start lever fully forward but if I left the throttle closed and just pushed the cold start lever forward by about 1/4 of its travel the bike fired up right away every time. It might be worth trying with the cold start lever in different positions to see if there is an improvement. The optimum position of the lever will vary from bike to bike, depending on how it has been set up at the throttle bodies.
Hi Derek, yes there is a lever by the LH switchgear, it’s more a fast idle adjuster but could be termed a “choke lever” by some. I’ll try that this morning and will leave the throttle closed.
As fitted to my monster also and required for easy starting. Saying that I know of many with monsters that don’t touch it. Monster 1000 (2004) but I’m sure the S2R1000 which shares the same engine is servo assisted on the throttle bodies.
This indicates you have fuel and spark and the fuel is, eventually, being ignited in order for the exhaust header to get warm, yet the engine won't start and run so it seems to me there's an issue with the timing of the fuel/spark mix. I'm guessing the fuel eventually ignites as there's so much of it unburnt in the cylinder. You must have disconnected the spark plugs when replacing them and doing the service are you sure you didn't put the H on the V by mistake? I'm not familiar with where the coils and leads are positioned on that bike and this may not even be possible and I know I suggested the coils above but just make sure the right spark is going to the right cylinder at the right time.
