Hi Forum,

Merry Christmas!

I left my nc30 stand for a year with the fuel tap on with fuel containing alcohol. Upon starting it today it started leaking fuel heavily. I'm planning on removing the carbs in the morning to see if I can fix it.

What parts could have been damages causing the leak?

Br,
Kris

Leaking all over the engine, or leaking into the cylinders? If fuel is leaking into the cylinders, the the main float valves in the carbs can be gummed up and sticky. If it was leaking over the top of the engine, it may be in the fuel tap. I had a problem with bad diaphrams inside the fuel tap which caused fuel leaks all over the top of the engine on an NC21.

If the carbs are leaking over the top of the engine, maybe the o-rings on the fuel tubes between the carbs have failed. I haven't had that specific issue, but it could happen.

Leaking on the ground. Checked the fuel tap it'S fine but now I can't start it. I think I need a new set of plugs...

as a precaution would drain the oil and change the oil and filter before attempting restarting if its been flooding.

Whats the alcohol for to stabilise the fuel ?
dry the plugs out in oven or blowtorch and get some fresh fuel .

The alcohol is because some of us live in countries where ethanol is added to perfectly good gasoline for various reasons. Among those reasons are emissions, increasing octane ratings, or to make corn growers happy. USA is certainly one of those countries, and apparently other places share this stupidity.

Leaking on the ground doesn't help - try to figure out where it is leaking from (I'm sure you realize that). I wonder if it is coming from an overflow hose somewhere.

You may want to check that the fuel system is compatible with ethanol/alcohol added fuels. Some rubber/plastic parts can be adversely affected by these additives.

Also alcohol is hydroscopic and thus any fuel with alcohol as a component can be problematic when left for an extended period in an unsealed container, it will attract water.

Got you now re the alcohol/ethanol Horrid stuff had a plastic fuel can left in shed for hedgetrimmer with fuel in it for a few months can swelled out of shape and that was a thick heavy duty can.
As magg said its hygroscopic as well creating water/condensation in fuel systems .