Fuel in crankcase how much damage?

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?

Failure to use an aftermarket inline fuel filter will allow grit and crud in the incoming fuel to instantly contaminate the carb internals, including the float needle/seat interface, regardless of how perfectly clean the carb was beforehand.

Where did the fuel on the ground come from?

Do these carbs have overflow tubes routed to exit underneath the bike?

Sometimes there's a drain tube from bottom of airbox.
But in this case don't know yet whether dealing with pods or air box.

Perhaps there's a clogged overflow on the same carb where excess fuel is getting into the floatbowl. Without an inline fuel filter, the dirty incoming fuel can also clog an overflow circuit.

It only takes one faulty carb to allow situation where fuel may enter the crankcase.

Good Luck!

For five minutes of running time, I vote probably no severe damage (of course, my vote and a dollar will almost get a cup of coffee :laugh: ). Mixing gas or solvent into the oil doesn't instantly turn into no oil at all, it makes it really thin oil which is still way better than no oil. I mix solvent into motor oil all the time to make thin cutting oil for sharpening knives or stoning metal parts.

To be safe (if it was mine): buy four quarts of medium cheap decent oil. drain and refill the bike engine. Run it up to full temp and dump the oil and filter. I would take the spark plugs out and use the kick starter to pump the engine oil dry to get all the crappy oil out. Then refill with good oil and install new filter, pump the clean oil up into the engine with the kick starter and you are good to fly.

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?

There's a trick to getting the needles to seat:

Put the needle in a hand drill (tapered end out) and polish the tapered surface with 600 paper and oil until it is glass smooth.

Put the brass seats in the drill (protect the brass threads with masking tape) and spin it slow and polish the inside surfaces with Q-tip and chrome polish.

If you get a good seal on the tapered needle face with the brass seat, they will NOT leak, even if you forget and leave the petcock on. This is a service you have to do every 6 - 12 months to keep tight seal. Brass will oxidize and gradually the seal loosens up over time.

Big +1 on inline filters. If you don't have them (and keep them clean) you will spend the rest of your life fiddling with carburetors..... gravity is a real beeatch, and water is heavier than gas.

The bike is an 1981 totally standard including airbox and mufflers its almost identical to the one in my gallery pic.
Thanks for all the help and advice I have replaced the tap with a new one and pulled the carbs off and they are spotless and no leaks from the seats on a bench test,so I don't know why maybe like you say a bit of crap got in one of the seats ???.It also has a new inline filter and I dumped the perfectly clean oil and filter and put new in.i pulled the old filter apart in a bowl of fuel and not a single shiney particle and nothing in the oil either.
I have done everything I can other than compression test it and have a peak at the cams so it's in the lap of the kawasaki gods now.

There are lots of engines,(mitary, airplanes,and etc.)that have been modified for cold weather use. At the end of the day, the engine is flooded with fuel so that it will be easier to start the next morning. After the engine is warmed up, the fuel evaporates and you do it again the next time the engine is run.

bountyhunter wrote:

I mix solvent into motor oil all the time to make thin cutting oil for sharpening knives or stoning metal parts.

Hmm... thats a good idea... me likes!

:laugh:

With bike transmission in neutral, engine idling, bike on sidestand --- watching fuel escape to floor ---

Sometimes it helps to rap smartly against the float bowls with a plastic hammer (or similar tool) as this will often restore full closure to the float needle/seat interface.

Good Luck!

bountyhunter wrote:

gravity is a real beeatch, and water is heavier than gas.

This is exactly why i use water in my hanging reserve tank setup I use for carb setups. Water passes by seals that gas seems to be more easily retained by, thus if your seats can hold back water fine, your good to go!

I also like to use "blue magic" polish for this job. It seems to not cut as hard as mothers and the like, and makes for fantastic fast seal.

Cheers.

Highspeed. What's done is done.roller cranks are amazingly resiliant. Plane bearings less-so. correct your' probs' and ride. probs w roller crank will develop knock at low rpm under load, plane bearings, the same and lower oil presure. damage due to oil contamination is rare but possible. luck g