Fuel leak seen on carb body

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markv
Posts: 31
Joined: Fri May 29, 2015 6:12 pm

Fuel leak seen on carb body

Post by markv »

Hi

Background: So my 410K is in Sweden, and I really need to get it back to the UK without spending too much time at it's storage location, where it's been sitting and mostly not driven for two or more years. I bought it a year ago, I'm a pinz noob, and can't leave it there for much longer.

While I was in Sweden recently I took the vehicle out for a drive around and found clutch cylinder problems now being fixed by a local garage. While discovering those problems I had the engine cover off to get to the clutch bleed valve to do a bleed. At that stage I saw dampness on a carb body, no doubt a fuel leak.

I had other stuff to do, so didn't think to try to track the leak down then.

In fact, the fuel leak didn't seem bad to me, it was just some dampness, but now I am feeling a little nervous about this, eg maybe loads of fuel was just evaporating off.... And now I'm wondering both about my fuel consumption on the way back and if the leak is indicative of a larger problem that causes the pinz to breakdown on the way back.

The carbs are setup fine as far as I can tell, they were tuned and balanced by a pinz and unimog guy maybe two years ago, the engine starts easily and the vehicle drives around just fine.

Im wondering what I can do if I had half a day or less to spend on this.

One thought is that I should, just in case it's needed, have some new fuel line with me, does anyone know the internal diameter and length needed please? But I doubt that fuel line is anything to do with the problem.

The distance I need to drive is about 250 miles / 450 km.

Any advice would be most appreciated please folks.

Thanks
Mark

I have read all posts here that seem relevant, and spotted but not read yet these

http://www.goatwerks.com/carbarticle.htm
https://porsche356registry.org/article/30
https://porsche356registry.org/article/46

However, as I said, I don't want to spend too long in Sweden, certainly not long enough to rebuild the carbs
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audiocontr
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Re: Fuel leak seen on carb body

Post by audiocontr »

Condensation builds on carbs. Perfectly normal. Make sure it's fuel before worrying too much. Then determine where the leak is occurring from.

I'd have more concerns if you see fuel drip within the carb after shut off. Even then, it's not a destruction scenario. Just adjustment.
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
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Jimm391730
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Re: Fuel leak seen on carb body

Post by Jimm391730 »

And check to ensure that the carb screws are snug; the top screws are easy, but there are four screws UNDERNEATH the carbs, you need to remove the carb from the manifold to get to them. Often these can be determined to be loose if you try to move the top of the carb while still attached to the manifold; you should not see any movement between carb sections with good hand pressure.
Jim M.
712W and 710M
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4x4Pinz
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Re: Fuel leak seen on carb body

Post by 4x4Pinz »

Jimm391730 wrote:And check to ensure that the carb screws are snug; the top screws are easy, but there are four screws UNDERNEATH the carbs, you need to remove the carb from the manifold to get to them. Often these can be determined to be loose if you try to move the top of the carb while still attached to the manifold; you should not see any movement between carb sections with good hand pressure.

but you must remove the air intake assembly. Too many times I have asked owners if the carbs are loose and they say no. Upon inspection of the truck after removing the air intake the carbs move all over the place.
markv
Posts: 31
Joined: Fri May 29, 2015 6:12 pm

Re: Fuel leak seen on carb body

Post by markv »

Brilliant, thanks so much 4x4Pinz, Jimm391730, and audiocontr.

Does anyone know the other part of my question please, the internal diameter of the fuel supply piping? And perhaps how much of it there is in a 710? I'll buy some in the UK and take it over to Sweden with me, just in case I need it. This kind of thing should do me I think:

https://www.advancedfluidsolutions.co.u ... -610-p.asp
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pcolette
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Re: Fuel leak seen on carb body

Post by pcolette »

The 2 sizes of fuel hose are 7mm from tank to gas filter and 5mm for gas filter to pump to carbs. About 4 feet of each should do it along with some good quality hose clamps.
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
markv
Posts: 31
Joined: Fri May 29, 2015 6:12 pm

Re: Fuel leak seen on carb body

Post by markv »

Thanks Paul.

My life is complete (well, for now, at least regarding information :lol: ).
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