2.0 air cooled white smoke and strong petrol smell

[Taggy]

Hello all.
I came to start the t25 today and it ran really lumpy and had no power with lots of white? Smoke and a really strong smell of petrol. I've just changed plugs and it ran well until I drove it a short distance. I will as thinking a shot spark plug and unburnt fuel into the exhaust. Causing smoke and smell. Do you think I'm on the right lines as it ran no problem before I put it away. Or am I way off? Really not sure at all!
Thanks guys

[Taggy]

Forgot to add the engine was rebuilt by l.pettit around 1500miles ago. I've also has another look and seem to have some leakage around the carb base.it seems oily thick one one side and petrolly on the back side? I'm not sure what any of that means! I have ordered a gasket set anyway. Just annoying as it ran sweet as before laying up. It does have an oil leak but I can't see how that would result in smoke from the exhaust! Arrrrghhh!!!!!
Cheers

[ghost123uk]

Rich over fuelling smoke from a petrol engine is black in colour. White smoke from a petrol engine is normally associated with water, but yours is air cooled. However, on cold days, when you first start up a petrol engined vehicle, and while the silencer is still cold, it is normal for white steam to be seen. Easy to tell if it is steam (not smoke) as steam quickly disappears after it has come out of the tailpipe, whereas smoke would hang about until the wind dispersed it.

I am going to guess that the white stuff is pretty normal steam, and you have a choke problem causing it to run rich (and smell of petrol). Sadly I know little about air-cooled carb set ups.

E D I T = spelling !

[ghost123uk]

p.s. Steam / water vapour is a normal by-product of a petrol engine and the over rich mixture would produce more steam than normal.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Aside = To the pedants out there = Yes I know the stuff you can actually see is water vapour as steam is actually invisible, but everyone calls it "steam" don't they

[marlinowner]

Accidently put diesel in?

[Taggy]

There was petrol being blown out the exhaust which is why I suspected the plug not working. It's def not got any diesel in it. I did think bad petrol but now I'm suspecting a carb problem. I guess I'll wait for the gasket kit then get the carbs apart and look for a stuck needle or wear I guess could be the culprit!
I'm pretty sure it was smoke though. I'll have to check!
Thanks all for the replies!

[ghost123uk]

There was petrol being blown out the exhaust

Are you sure it's petrol (not smelly water). To actually chuck neat petrol out of the exhaust it must be pouring into the engine. remember the petrol going into the engine is normally a gas, not a liquid (that is what the carb does). I have never seen actual liquid petrol in an exhaust. You do get droplets of water when it's cold, which of course smell of petrol.

[Taggy]

It felt slick if that makes sense. More than just water but I Guess it could be water and vapour petrol that's maybe condensed in cold exhaust? It's entirely possible it was mainly water! I'm going to check the airbox for water as we've had high winds and rain here lately. I was tempted to leave it running and see if if cleared but I was scared of damaging something! I hope it's just that As it ran sweetly before leaving over winter. Two of the plugs were very sooty so I think carbs aren't helping fuel mixture at the same time! (Gaskets due Wednesday!) Though for a supposed rebuild the plugs looked aged!
Sorry for lengthy replies! can you tell I'm new to Aircooled!
Thanks once again!

[ghost123uk]

Replies aren’t too lengthy, we need the info to help.

Re the two sooty plugs, assuming they are on the same side, then I suspect either a sticking / faulty choke mechanism or the float chamber flooding due to a faulty / worn out needle valve. That needs checking as simply cleaning and fitting gaskets is unlikely to effect a cure.

[Taggy]

Cheers. I know gaskets won't sort the problem, I just wanted them before I took things apart! I've done bike carbs before.
However I got a chance to leave work early today and......took the airbox off to find the left ( as you look at it from rear) carb butterfly well and truly wedged solid shut! It took a solid tap with a wooden dowel to move it. It was bent slightly so it'll be replaced I just need to reprime the fuel system as I've run it down trying stuff out. It is turning over well and I've got oil pressure so hopefully it'll run ok again. Though how it got into that position in the first place is a mystery!
So does anyone know if you can still get bits for the solex carbs? I'd love to put a better one on just can't afford it at the minute! I'll double check needles etc when I get them off!

Thanks again guys!

[BOXY]

carb butterfly well and truly wedged solid shut! It took a solid tap with a wooden dowel to move it.

The choke flap is only held shut by mechanism in the auto choke. Pushing the throttle forwards should "un-lock" it. If you've used a hammer it might be worth taking the cover off the choke and making sure you haven't bent anything inside. This photo shows the inside.


The lug arrowed is what the choke spring latches onto.

[sarran1955]

Hello,

This might help..

https://www.youtube.com/watch?v=najLc9GlLJ0" onclick="window.open(this.href);return false;

Cordialement..

[Taggy]

Thanks for that. Really appreciate the help!
It was really wedged into the actual body of the carb. One I popped it down it all seemed to react the same as the other side. I will def get it apart now I've got the rebuild kit. I think the auto choke may have stuck on though as there was a lot of blue smoke when I started it and took it for a short run. Turned it off to move other car. Restarted and no smoke at all! At least it ran!
Now to rebuild and tune it up!

[Taggy]

Well it now appears I have fuel In the oil. Could worn carbs leak fuel into open valves if its parked nose down? I thinl its more likely nose up? I suspect its fuel pump diaphragm can't think of any other way for it to?? ....oh well at least I'm going to get to know the motor well!
If anyone has any suggestions.....or knows the best place to get a rebuild kit from?
Cheers!

[ghost123uk]

Well it now appears I have fuel In the oil. Could worn carbs leak fuel into open valves if its parked nose down? I thinl its more likely nose up?

Unlikely. It could have got into the oil via the rings whilst running very rich (stuck choke) though. depends on how much fuel is in the oil. Normally via that route it would not be too bad.

However, a duff fuel pump diaphragm can certainly dump lots of fuel into the oil

I am sure you know this = after you fix the problem you must change the oil straight away