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Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 12:01
by johnfevs
I have got an air cooled 2000cc engine. The problem is that there is a strong smell of petrol in the engine compartment. This smell comes through into the cab when driving. Can anyone out there point me in the right direction, as I do not know much about engines, but willing to learn.
I am going to have a good look around the compartment today and see if there are any fuel leaks or obvious problems.
Also the near side heat exchanger has a hole where it joins to the exhaust pipe which I have sealed for now but it is also blowing at the other end as well so assume a new one is required.
I bought the van expecting to have to spend a few quid on it so not a major problem hopefully as I want to go away in it next weekend
Thanks in advance
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 13:10
by jason k
do not drive it! id change all fuel lines starting at the tank outlet to the carb via the pump. then start looking at tank breather pipes too.
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 14:30
by johnfevs
The smell seems to be coming from the right hand side carb. When I feel around the carb the is a strong smell of petrol on my fingers.
The fuel lines look ok and some have been obviously replaced fairly recently within the engine compartment.
I will make sure everything is tight as my next step
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 14:37
by Mocki
Either the float is stuck in that carb, or the seals are gone round the float chamber
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 15:11
by johnfevs
I have tightened the screws on the top of the carb, slightly loose and gasket seems wet with fuel.
Tightened the fuel line at the top of the carb, gave it a twist to make sure it was tight and the brass spigot that goes into the carb came loose. I have tapped it back in and seems tight. Checked the left hand carb and this is tight. Does this brass spigot (not sure if correct term) just fit in there ?? It doesn't look like anythings broken off.
I'm going to refit everything and start him up and see if I can see anything.
As a note, directly under the carb is a inverted v shaped pipe which has a clean spot where it looks like something might be dripping onto it which Is below where the fuel line enters the carb.
Thanks in advance for everyone's help
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 15:26
by CovKid
Some leaks are not evident without hatch up and engine running:
https://club8090.co.uk/forum/viewtopic.php?f=37&t=123828" onclick="window.open(this.href);return false;
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 15:34
by johnfevs
It looks like it maybe the top hose to the carb or this brass spigot. I will run it up and see if I can see anything
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 16:13
by johnfevs
Ok, here's where I'm at. Cut back top fuel line to carb and re tightened . Let it run for 10 mins or so and rechecked for any fuel residue around the carb. All looks ok. Smell of petrol no where near as bad as earlier, but it's hard to tell as I've been sniffing petrol all afternoon. I'm going to put everything back together wash up and take him for a drive, hopefully my head maybe clear of fumes by then and I can recheck.
Whatch this space
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 16:45
by BOXY
The spigot was probably an interference fit when new. It would have been pressed in to hot carb body to make a fuel tight joint. If you've only pushed it back in, it'll probably vibrate loose again. I'd get some stud lock and seal it back in permanently. A fuel leak from a twin carb is right above the hottest part of the engine.

Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 17:59
by johnfevs
Just came back from a 20 mile round trip. Smell in side not noticeable. No fuel residue around the carb. What I have noticed is the air supply pipe from the air filter, the bit that sits on top of the carb with the 2 pipes coming off of it is oval where it sits on the carb, and not making a vey good seal, I will try and order a new part for this, where is best for these parts.?
Also going to reseat around the engine compartment as this seal looks pretty useless and won't we helping
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 19:01
by kevtherev
If the fuel lines haven't been replaced, please change them anyway as a matter of course.
Re: Strong smell of petrol in engine compartment
Posted: 06 Oct 2013, 20:59
by johnfevs
I am trying to find a replacement for the twin pipe that fits on top of the carb and goes to the air filter, but can not seem to find one anywhere. Any ideas ????? Also should the bit that fits on top of the carb have a retaining clip, the picture in the Haynes manual looks like there should be one but mine doesn't have one??? Maybe this is why it's not sealing ????
Re: Strong smell of petrol in engine compartment
Posted: 07 Oct 2013, 16:33
by BOXY
Mine doesn't have any clips, it just pushes onto the top of the carb. If yours is oval you could try heating it in boiling water to soften it. Then push it on to the carb and see if it re-forms less oval as it cools down. You can adjust the clips on the two pipes to make sure it sits centrally on the carb to stop it getting pushed out of shape again.
Re: Strong smell of petrol in engine compartment
Posted: 07 Oct 2013, 18:49
by Kent Joker
I wouldn't go as far as to say its common but it DOES HAPPEN I'm glad your keen to learn but this may not be the best thing to learn on once you realise it's I light it will be to late to put it out!

Re: Strong smell of petrol in engine compartment
Posted: 07 Oct 2013, 18:51
by johnfevs
I went to TPS today to see if they could get a new end piece pipe, they had a part number but then came back and said it was obsolete. The chap did let me have a copy of the exploded view and the part numbers. On the drawing it shows a clip where the pipe sits on top of the carb so I'm going to try and fit one.
Checked the carb tonight prior to fitting the clip and noticed that the gasket around the top section of the carb is wet with petrol, not a lot but enough to see it on my finger. Could this be that the gasket is u/s or could this be fuel coming from the top of the carb where the pipe doesn't sit correctly?
I will fit the clip tonight and recheck the gasket tomorrow. Where can I get a gasket or is it best to make my own, if so what material and thickness do i need.