Idiocy... ER5 motorcycle motorbike misfuelled.

OK, so this is not my finest hour- pretty embarrassing tale really- bike nearly ready for MOT I needed to wash it and fuel it and.... yes I mis-fuelled-it and added 5l diesel! All I can say is that this is surprisingly easy if your mind is elsewhere. In my case I was filling a 5l can and was concentrating on the can to make sure I got no overflow or blowback. I didn't look at all at the filler hose I was using!! 

Anyway, 5l of diesel inserted... I wasn't aware anything was wrong but the bike  wouldn't start, then did and ran like crap- missing backfiring and smoking! The motor then stopped and this was followed by an efflux of fuel from the middle of the bike- subsequently I discovered this was pouring from the air intake. Clearly something seriously wrong! 

I now know that this overflow is typical of fuel tap malfunction. It could have developed in storage quite by coincidence, or it could have been caused by the diesel. In any event cleaning the system as described here, although necessary, will not cure the problem which will recur whenever the tank is full be it with petrol or diesel! 

By this time as the truth dawned I had already tried to start the bike and presumably filled it with diesel. Unlike petrol, diesel doesn't vaporise and the carb must had delivered it like a straw to the intake manifold- this had flooded with fuel that had flowed backwards and out of the air filter. I removed the filter and cleaned the air box as best I could but clearly more will be needed. I have formulated a plan as such.

1. Strip out the carbs and clean them- I'm hoping that as the top and bottoms are detachable I can clean them without decoupling and thus breaking their throttle synchronisation.

2. I need to remove the exhaust which could also now be full of fuel.

3. Remove the plugs and spin the motor to clear diesel- add some fuel to help clear this.

4. Change oil in case diesel has contaminated this, fit new air and oil filters.

5. Drain and flush tank with petrol

Of course if there have been significant hydraulic lock effects then the piston and or conrods might be damaged, but if so the the bike will be beyond economic repair and I'd need to look at second hand motor.

OK so first step: remove the carburettors.- I removed the seat and side panels in preparation. The bike is festooned with hoses! All any decent bike needs is one(two) hose(s) from tank to carb(s) but no one told Kawasaki! The bike is crowded with air hoses, vacuum hoses, fuel hoses and coolant/heater hoses. Madness!

Side panels and seat removed.

The fuel tap was set to Run, it was stiff although it eased with penetrating oil. In order to remove the tank this must be on Run or Res NOT Pri.

Remove the two screws holding the fuel tap to its bracket

Detach the battery- you don't want sparks.

Remove the earth connection.

Detach the two Allen screws holding the fuel tap. This tap is a case in point when it comes to over-provision of hoses! There are two fuel hoses in, one fuel hoses out and a vacuum hose linking the tap to the carbs. Pull off the vacuum hose. 

Removing the vacuum hose from the fuel tap.

Disconnect the tap to carb fuel hose, one is at the front clipped to the air box, but the second is hidden towards the rear of the tap.

detaching the second fuel hose

Next, release the tank rear mounting bolt, lift the tank at the rear and detach the vent hose from the front of the tank (awkward to reach). The fuel tap and its hoses can then be finagled out and in my case once released I could drain the tank. I obtained about 6l of petrol-contaminated diesel.

Remove the rear tank mounting bolt.

... and disconnect the fuel gauge multi plug.

Disconnect the fuel sender wiring at the multiplug.

What's left is a mess of hoses! I suspect at least one of my hoses is already mis-routed, it crosses diagonally and ignores the obvious hole in the seat mounting bracket.

Under seat view- note hose running diagonally to right that should probably go through the seat bracket on rhs.

In the ER5 the seat  rear bracket has to be removed as well to get at the carbs. There are 4 bolts on the side and 2 in the rear centre

Unscrewing the tank bracket, 2 centre bolts already removed.

When all 6 are out the bracket just lifts off.

Removing the tank bracket.

The tank vent hose passes through the lhs hole in the seat bracket- I suspect the other hose should pass through the rhs hole.

The tank breathger goes through the lhs side hole in the tank bracket, I suspect the rhs hose should go through the other hole?

I had to detach the left hand carb heater hose- coolant drained out as I forgot to clamp it! However it needs to come off in order to give enough room to release the fuel tap. Ah well, I needed to check/replace coolant anyway! I think these little balloons are a visible check on coolant, formerly filled and blue they are now empty and clear. All hoses and clips look a bit suspect but swapping them is a task for another day.

lhs carb heater detached

I didn't make the same mistake on the right where I clamped the hose before disconnecting it from the carb mouth. Horses, stable doors???

Clamping the rhs carb heater hose

The double choke system slides on a sliding rack between the carbs at the front. Its hard to see  but if you slacken  the cable at the handlebar end this gives enough room at the slide to rotate the cable and slip the nipple through the groove in the slide.

Choke slide in front of carbs.

Cable detached from choke slide

Next step is to loosen the  jubilee clips holding the carbs to the manifold rubber adaptors- centre in this pic.

You can then also loosen the clips on the rear rubber mounts holding the airbox to the carbs...you could at this stage remove the carbs themselves leaving the airbox in place if you want. I need to clean the airbox out as well so I opted to remove it first.

Airbox to carbs intake rubbers

There is a fuel hose running round the side of the airbox and clipped to it... you need to unclip it; although its fiddly and I don't think the clip will be reusable.

Have to unclip this hose

I pulled the air hose connection from air box to carbs...

Detaching the air box hose (vacuum?)

..and you can then finagle the air box out of the frame- it was tricky as there was barely enough room.

Airbox out!

This leaves the carbs in position.

Air box out, oil bath breather visible below, carbs in position lower right.

Before removing the carbs loosen the throttle adjuster fully at the handlebar end and  detach the throttle cables at the carb end. I found that if the lower nut is left in position the the upper nut can be released to give enough slack to slip the cable out of the mounting bracket. Well- this worked well for the lhs cable but wasn't so successful on the right. In the end I did need to release the lower nut on the rhs but made a mental note that the adjuster on this carb is screwed practically all the way down. I labelled both cables with tape so I could tell which carb they served. The action will need to be checked for synchrony later. 

Releasing the left hand cable could be done entirely from the top but the rhs adjuster is screwed too far down for this.

Once the cables were released there was enough slack to rotate them and slip the nipples through the quadrant pulleys.
Release the two carb heater hoses one each side (I had released the LHS already) and detach the vacuum hose from each carb- again label them left and right.

RHS cable removed coolant/heater pipe on right

Finally the carbs can be eased out of the rubber manifold connectors and removed from the bike as a pair.

I removed the top and bottom covers.... Surprisingly I found no diesel  inside either. 

This was a really good sign, but given that diesel had been entering the intake system, it is possible it had passed through the cylinders and been pumped into the exhaust. This being the case I needed to remove the exhaust in order to be sure it wasn't full of diesel. In the event this proved somewhat tricky; firstly access is poor so I decided to remove the radiator and fan as well and secondly, all 4 of the exhaust securing bolts sheared off their studs when I tried to undo them. 

stud remnants left in exhaust manifold after the studs had sheared.

This caused a lot of consternation but eventually the stud remnants were removed using a combination of extractors (Irwin spiral nuts) and welding a normal nut onto the studs. I was then able to clean up around the exhaust system remove the spark plugs insert some carb cleaner into inlet manifold exhaust manifold and the cylinder and then spin the engine on the starter in order to clear any diesel from the cylinder head. 

Although access to the lhs plug isn't too bad (use a long plug spanner) access to the right plug is blocked by the radiator hose. As my coolant system was empty at this stage I simply removed the hose. Blast out any debris around the plug holes with an air line before removing them.

rhs plug access blocked by radiator top hose. Remove to make plug removal/replacement easier.

spark plug- old top and new bottom

I fitted new exhaust studs, these are stainless steel studs with an Allen key fastening in their ends.

New and old exhaust studs.

Spinning the motor was quite successful, and I did not find a large amount of diesel was expelled. In fact  it was probably simply a cloud of carb cleaner. I was then able to replace the spark plugs which clearly had seen better days before moving onto the last task which was to drain the oil.

Fitting the new plugs has to be done carefully to avoid cross threading. I used a length of tubing to support the plugs as I made sure they were threaded by hand pressure alone.

I had not expected any particular problem with the oil and my intention of draining it had simply been as a precaution. In fact, oil contamination turns out to be the single biggest consequence of the misfuelling. Anyway, I didn't yet know that, so as is my usual habit, I placed a small drainer can under the sump plug remove the sump plug and expected to catch the oil. To my amazement what piddled out was a thin, constant stream of diesel mixed with oil in very large amount. I recovered something like 6l!  

Collecting the thin watery diesel oil mix!

Obviously diesel had entered the crankcase, mixed with my oil and presumably had disastrous consequences for engine lubrication. Since the engine did not run,  I'm hoping this hasn't done any serious damage but it does mean that I will need to flush out the crank case in order to remove any remaining diesel before I run the motor with any  determination.  I decided I would remove the oil filter because that will also be full of diesel, allow both filter and crankcase to drain completely. I could then  refit the old filter before filling the motor with cheap 10/40 oil. I will then wait until the carburettors are reinstated and I can start the motor  and give it a few minutes of circulation to flush any remaining diesel. I will then carry out another oil change this time fitting a new filter.

This does of course raise the question how did the diesel get into the engine oil in the first place. There is no obvious connection between the intake system and the exhaust system and my first thought was that the diesel was being pumped past the rings in the cylinders on the compression stroke if this is the case then it must indicate the Rings are seriously damaged and probably implies that the motor has no future. However I am surprised that diesel could enter this way in such quantity. Fortunately I remembered the peculiar oil pan (whose function I do not know) situated below the air box and connected to it by a simple hose. Since I know the air box did fill with diesel this would provide a simple and less catastrophic explanation! 

Rear exhaust mounting bolt behind pillions footrest

Exhaust mid mounting below riders footrest.

Exhaust brackets fitted using new studs and nuts

Assembly is as they say the reverse of dis-assembly. I found it was tricky but most of the fastenings did seem to be self explanatory and I worked out the hoses with no real problem. Once the rad was on  I added the alloy trim chevrons and the carbs. Connecting the cables was tricky and I'm not sure how they can be adjusted since the bottom nuts can't turn in the  brackets/holders and the upper nuts can only tension against the lowers! It seems like you should use the upper nuts as locknuts, loosen these and then screw the adjusters in and out of the lower nuts to set cable tension. However the adjusters appear to be immovably crimped onto the cable body which means they can't turn unless the whole cable turns- and this is impossible! I did the best I could by removing the cables entirely, adjusting the lower nuts up or down and then refitting them. I got it close but not exact!

Once the carbs were on I could add coolant (1.5l needed of 30% mix) and use a temporary fuel tank to attempt starting- which to my surprise it did well!! I tighhtened the exhaust clamp brackets as there was a blow from the new gaskets. Once this was sorted I fitted the air box including a new air filter. Do not tighten any of the large carburettor  hose clips (ie to intake manifold and air box) until you have also fitted the tank as all these components need to move to accommodate one another and line up the tank bolt holes. The rhs carb will dribble unless the vac line to that carb is blocked (at this stage I had not fitted the fuel tap).

The motor needs to be run up to temperature before topping up the coolant but I wasn't able to do this as I am still flushing the diesel-contaminated oil so it was only a short run. I will now leave it overnight and then drain the oil once more, fit the new filter and run up to temp before checking coolant. Finally, I can reinstall the fuel tap and rinse the tank in petrol prior to refitting that.

Overall then, the most serious consequence of the misfuelling was contamination of the oil and air box. If there had been diesel in the carbs it would have flushed through with new fuel. If God forbid this ever happened again. Then I think its a case of drain and flush the tank, dry the air box and replace the air filter. Drainn the oil, flush and refill with fresh oil and a fresh filter.

So all completed and hopefully no harm done... Back to MOT I think.