Petrol in exhaust on KZ1100!

KZ been a bit rough starting in garage over winter so treated to new plugs and took for a wee run. Clearly not firing on 4 cylinders I stopped and put on side stand. Petrol then came from exhaust joint !!!!

No1 exhaust cold! Checked plug and sparking away. Drained carb and tried to clear petrol but quickly built up again.

So can anyone help? Would a stuck open float valve do this or is it engine internals I should look at and if so what?


Cheers fergie

A stuck float will certainly cause that problem. It might just be a bit of trash. A careful cleaning with a cotton swab and a new fuel (petrol) filter may be all you need. If you lived in a place that sells gasoline rather than petrol I'd also suspect that.

Aye, stuck float valves, or even floats, can contribute to what you're describing. As TexasKZ said, a new fuel filter would be a great start, and then cleaning the carbs. You can try running some seafoam through your fuel system, I'd recommend doing it straight, and overnight, to really clean out anything. It also might be a good idea to make sure your fuel is turned off when you park your bike, just in case things get stuck in the open position.

Would examine the crankcase oil for possible fuel contamination.

Good Fortune!

Cheers for that. Will take carbs off and give them a strip down clean. Fuel is always off as the vaccum tap works fine otherwise I suspect I would have a puddle of fuel!!!

Suppose will also need to do an oil change when sorted as no doubt petrol sitting in piston will have seeped down!

I hope it's a straight forward fix as I have a very busy 6 months coming up and just want to do some miles rather than be in workshop when free and as much fun and practical my piaggio 2 stroke scooter is its only for in town.

Carbs stripped cleaned and rebuilt and still fuel in the exhaust!

Did a compression test and no1 is about 60% of no4 so best guess now would be a stuck valve? Unless anyone else has great pearls of wisdom?

Did you happen to check that cylinder (and the others) valve clearances?

Not got time to take cam cover off yet so no chance to check clearances yet. Going to be a head off job unless I am missing something? :dry:

Wha?

No - clearances is just a valve cover off job. Check those first.

fergieuk wrote: ...still fuel in the exhaust!....

Suspect leaking float valve.
Combined with inoperative overflow circuit (if so fitted).

Good Fortune!

Patton wrote:

fergieuk wrote: ...still fuel in the exhaust!....

Suspect leaking float valve.
Combined with inoperative overflow circuit (if so fitted).

Good Fortune!

Likely, but 60% compression isn't from a leaky float valve.

DoubleDub wrote: Wha?

No - clearances is just a valve cover off job. Check those first.

ah yes, separate valve covers unlike my Yam XS11!