Fuel in crankcase how much damage?

I ran my kz1100 with a lot of fuel mixed with the oil,I did not realize the fuel tap had failed and dumped 2 litres of fuel in there until it stopped running after about 5 minutes or so.It had sooted up the plugs I guess from the oil being to thin to seal the cylinders.Have fixed the fuel tap with a new one and changed the oil.It all runs fine again but wondering about the possible damage done?

When straight fuel gets in the cylinders, eats the oil off of the cylinder wall. When the bike is run with a persistance condition, it can ead to excesive ring/cylinder wear, thus compression loss.

If the concentration is high enough, it will turn the lubricating properties of your oil to spit, and all metal-on-metal contacts will suffer excessive wear.

There may have been some serious damage done, or not. A compression check, and valve train inspection should be done at the least.
Its a good thing it only ran 5 mins, you probly got away with it.

Good luck.

i doubt it how long did it run?
if anything it would have nicely cleaned all the crud out when you drained it all out,

did you change the oil filter too?

kano wrote:

i doubt it how long did it run?
if anything it would have nicely cleaned all the crud out when you drained it all out,

did you change the oil filter too?

No just drained the old oil out of the cavity as it had done about 200ks on filter and oil change.I will change the oil and filter again on the weekend.The bike seems to run as normal but I think I will give it a compression test on the weekend.Very pissed off as the bikes mint and now every noise leads me to believe I damaged it.Which may not be the case.

Thanks for help.

the noises you here are normal bro.
ive owned the same bike almost 20 yrs :blush:

been apart so many times its crazy, :blink:

when you know your bike you now how it sounds
and every little noise makes you think "did i tighten that bolt :laugh:

kano wrote:

i doubt it how long did it run?
if anything it would have nicely cleaned all the crud out when you drained it all out,

did you change the oil filter too?

No just drained the old oil out of the cavity as it had done about 200ks on filter and oil change.I will change the oil and filter again on the weekend.The bike seems to run as normal but I think I will give it a compression test on the weekend.Very pissed off as the bikes mint and now every noise leads me to believe I damaged it.Which may not be the case.

Thanks for help.

highspeedjelly wrote:

No, just drained the old oil out of the cavity as it had done about 200ks on filter and oil change. I will change the oil and filter again on the weekend... and now every noise leads me to believe I damaged it...

highspeedjelly ,

If it were my bike I would assume the worse and say that the filter was full of raw gas and the new oil is again contaminated. I would warm up the bike, drain the oil, change the filter again, add fresh cheap oil, warm up the bike, drain the cheap oil, add a premium non-anti-friction motorcycle oil, warm up the bike and do an engine compression test.

If I had Vacuum Gauges (which I do), I would immediately do a dynamic Carb sync to eliminate those supposedly trademark KZ engine sounds.

If all results were good, then I would have a good (comfort food) supper, have a glass of (add your favourite beverage here) and sleep the sleep of the peaceful, safe in the knowledge that I would have done all I could and that the rest was out of my hands.

Best of success.
Bill

PS
Could you add your year, model and location to your signature to get the best feedback... and yes, it's considered real friendly too.
Bill

Am thinking lower ends with needle bearings, such as the large fours, are more tolerant of this situation than are the higher oil pressure engines with insert type lower ends.

Anyhow, imo, simply changing the oil and filter and correcting the petcock is not enough. Because the condition may recur while riding, when the petcock is flowing fuel.

Excess fuel is entering the float bowl for whatever reason, and failing to escape through the overflow circuit (if these particular carbs have an overflow circuit).

Would not again run the engine until the issue is fully resolved. Problem likely relates to improper function of float valves or the float, for which the overflow is a failsafe and should also be operational.

With engine off and vacuum petcock in PRI (or manual petcock ON), fuel should not get past the float valves after rising to correct level inside the bowl. And even if it does, should escape through the overflow circuit (if so equipped).

Good Luck!

Are carbs fitted with pods, or drawing from airbox?

If airbox, is crankcase vent routed to inside the airbox (often via an S-shaped rubber hose)?

Good Luck!

don't sweat it buddy i've seen crankcases so full that the gas oil mixture was pouring out of the exhaust i drained it changed the filter and fixed the needles and seat put a fresh load in it drained out the exhaust put a fresh lod of oil in it and away we go.it happens alot some years you would have to be a complete twat to hurt one of these motors from this happening that is one of the beautiful things about these motors tough as nails. make sure you repair the needles and seats thou because this will be the main cause of your problems.

Thanks for advice.I will strip the carbs on the weekend.The needles and seats were replaced only 2 years ago but not genuine kawasaki?I don't understand why fuel did not end up on the ground as it did before I did the needles and seats?

highspeedjelly wrote:

Thanks for advice.I will strip the carbs on the weekend.The needles and seats were replaced only 2 years ago but not genuine kawasaki?I don't understand why fuel did not end up on the ground as it did before I did the needles and seats?

What year and model KZ1100 is it?

Good Luck!