Misfire -> Power Gone -> Kaput

Which bike model & year'

 

Rectifier?

 

Blocked fuel filter
Plug breaking down
Ignition pick up failing
If belt slipped that may put timing out?

 

It will start normally and idle on two cylinders fairly normally*? As already said, could be rectifier but would probably have shown up with poor starting by now, make sure you check connectors/wiring leading away from rectifier as a matter of urgency though. Could be fuel filter as said, and could be fuel hose split and breaking down inside tank. Last one is quite a favourite and would fit symptoms* best. Loose battery leads is another possibility, also two (?) relays worth checking but can’t remember location.

 

Failing crank sensor is another possibility.

 

Loose alternator/timing rotor?

 

Ar, ran out of fuel....I’d pull the filter and wash/replace and see how that goes. Likely it’s a bit clogged, so works ok under no load but can’t get fuel thru when needing power

 

1) rectifier
Connect a meter across the battery. With engine running at a fast idle you should see around 14V at the battery

2) fuel filter
By the time you have got into the tank you might as well replace it anyway.

3) plug breaking down (I assume spark plug?
Could be a coil breaking down. If you can identify which cylinder is misfiring. Swap the coils over and see if the misfire transfers to the other cylinder.

4) How can I check ignition pickup or crankcase sensors?
Replacement is easiest. Same as 1.2 Fiat Punto. Across the pins should read 860Ω ± 10%. If the are failing the cylindrical part of the body is often swollen. A faulty CPS will affect both cylinders or it won't run at all.

5) Can the belt slip?
Normally, no. It would have to be helluva slack and you would certainly notice.

6) it did appear to start normally and idle normally but I will recheck. I think partially blocked fuel source may be a contender. Is it easy to check inside tank for the internal pipes etc? I had strange issue few weeks ago where fuel empty light came on much later than usual (around 220k...normally around 180k) and I ran out of petrol.... since reverted back to around the 180k mark but more recently at 150k....could the internal tank gauge be failing and block the fuel?
Fuel sender can't block the fuel flow, it probably just got stuck. The fuel lines in the tank can split though, drastically reducing fuel pressure so that the engine will run very poorly or stop all together. It may maintain enough pressure for idle though.

7) Also, there was a bad rain storm and I am wondering if any water managed to get into fuel/connections anywhere
Possible but unlikely. Most likely to be affected would be the plug connectors / HT leads.

8) I will check battery connections
Always worth checking

 

with your symptoms I would head for the tank split line or fuel filter blocked with tank crud would be where I would focus

 

re:- split fuel hose within tank (question 6) - bike will idle as normal and throttle will even 'blip' fairly normally at low revs, it's only when you go to put a load on the engine that it will stall/will need coaxing - this from many vehicles going back to Lancia Integrale. Depending on how much is in the tank, there will always be fuel available for supplying injectors, just not under the right pressure. It's difficult to say for sure from visible symptoms but I remember one case where I could definitely notice more turbulence within fuel in tank when engine revved 'highly'. As you ran out of fuel there's a strong possibility that this is linked to the problem so (as said already) a strip of fuel pump unit will at least cross the above plus filter off the list. The removal sequence is described on this and many Forums, careful attention needed for 'quick-release' inlet and outlet connector removal/reconnection and re-inserting the whole unit back in the tank as regards large 'O' ring.

As you mention exposure to a storm then there are several items that could have been affected enough to cause your symptoms, some mentioned already. Was bike static during storm or did you ride during? Are you happy that bike will start, warm up and idle happily on both cylinders? (you can check both exhausts on cylinder head exit for temperature being careful not to get burnt)
Hopefully others can help shed more light on the problem as you possibly come across other symptoms.

 

@Chris, the S4R uses the IAW59 ECU which hasn't got a big grommet and the air pressure sensor is integrated into the ECU.

However, this bike does use stick coils and these are well known to be affected but water getting into the plughole area.

 

Sorry - got threads mixed up! - was bound to happen eventually - will amend as necessary. So front stick coil renowned for breaking down first but I guess it could be either depending on how severe rain/storm was.

 

When my old monster s4 did this it was a split fuel hose in tank.
When my 998s did this it was a data tool alarm causing an ignition earth at speed.
Fixed that problem then the fuel connector came off the bottom
Of tank and spilled fuel over exhaust. It caught fire and that was the end of my trip to thruxton bsb lol and my bike

 

It looks as though it still didn’t put you off getting another one though?

 

Nope not all! Couldn't wait to get another but it wasn't an s.
Made sure I checked the connectors as well

 

OP did mention sooty plugs so unlikely to be lean or lack of fuel?

 

Agreed. More likely sooty due to misfiring.