14 replies to this topic

[Hegnirst]

Im trying to figure what this leak is coming from? or why its happening, does any body know?
or familiar with this?
You can see where its coming from as its stripped the paint

thanks guys!

[KernowCooper]

Look like the choke cover leaking, there is a blanking plate conversion if you dont use it here http://www.dellorto....artsectionID=57

[Hegnirst]

Look like the choke cover leaking, there is a blanking plate conversion if you dont use it here http://www.dellorto....artsectionID=57

Look like the choke cover leaking, there is a blanking plate conversion if you dont use it here http://www.dellorto....artsectionID=57

The cover has a gauze filter at the bottom of it, there shouldn't be any petrol behind the cover. the problems a bit deeper than that.........But the blanking plate is the easiest solution......

Looks like it could be coming through the gauze filter (air filter) on the bottom of the cold starting mechanism cover (thats the bit just above where the paints missing, the gauze is at the bottom, remove the 2 screws and it'll come off........

i did think the choke mechanism, but i dont get why its coming out of there? thats the bit i dont under stand, whats this gauze thing?

thanks

[KernowCooper]

Fuel leaking out of the cold start (choke) mechanism on Weber DCOE carburettors is a well known problem, particularly when carbs are inclined like they are on the Mini-manifold.

I would check the float height which is set by the brass tabs in the middle of the float assembly. The height is measured with the floats held up with the needle and seat just touching, by using a steel rule from the underside of the top cover down to the top of the float should be 8mm.

The Droop when hanging down should be set at 15mm.

Fuel pressure should be 1.5 to 2.5psi

Depending on how worn the needle jet is is it possibly leaking, as this may over richen the idle.

The breather hole is in the airfilter next to the ram pipe and is about 1/2" dia, but if the carb is at an angle towards the engine it may still leak at the front (manifold) if the fuel level is high.

To check the float, knock out the small brass pin and shake the bass floats to see if there is any fuel inside them. You can check how worn the needle valve is at the same time.

Once your happy the float height is correct and the needle valve is not causing the overflow from the air circuit of the Choke mechanism, then thats pretty much all you can do

There's no cure on a inclined install like the Mini, but the mechanism, which is open in the bottom, where it sucks in air, can be replaced with blanks, which will improve the situation and close off the Choke open and stop any fuel coming out.

[Hegnirst]

Fuel leaking out of the cold start (choke) mechanism on Weber DCOE carburettors is a well known problem, particularly when carbs are inclined like they are on the Mini-manifold.

I would check the float height which is set by the brass tabs in the middle of the float assembly. The height is measured with the floats held up with the needle and seat just touching, by using a steel rule from the underside of the top cover down to the top of the float should be 8mm.

The Droop when hanging down should be set at 15mm.

Fuel pressure should be 1.5 to 2.5psi

Depending on how worn the needle jet is is it possibly leaking, as this may over richen the idle.

The breather hole is in the airfilter next to the ram pipe and is about 1/2" dia, but if the carb is at an angle towards the engine it may still leak at the front (manifold) if the fuel level is high.

To check the float, knock out the small brass pin and shake the bass floats to see if there is any fuel inside them. You can check how worn the needle valve is at the same time.

Once your happy the float height is correct and the needle valve is not causing the overflow from the air circuit of the Choke mechanism, then thats pretty much all you can do

There's no cure on a inclined install like the Mini, but the mechanism, which is open in the bottom, where it sucks in air, can be replaced with blanks, which will improve the situation and close off the Choke open and stop any fuel coming out.

should there be a gasket behind the choke mechanism?

[KernowCooper]

Just double checked the parts diagram and theres not one shown,but the sealing plate should have

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[Hegnirst]

Just double checked the parts diagram and theres not one shown,but the sealing plate should have

Look like the choke cover leaking, there is a blanking plate conversion if you dont use it here http://www.dellorto....artsectionID=57

The cover has a gauze filter at the bottom of it, there shouldn't be any petrol behind the cover. the problems a bit deeper than that.........But the blanking plate is the easiest solution......

well all i did was take the cover off, put some gasket sealant on then put back and no leak no smell weird!!!

[KernowCooper]

Interesting what sort of sealant ? petrol resistant otherwise it could come back again

[Hegnirst]

Interesting what sort of sealant ? petrol resistant otherwise it could come back again

its come back LOL but It was working really well, so i might just order that blanking plate, the thing i dont get is that why is it coming out because surely the 'air filter' which is there is just for air? this is making me really tempted to sell it

[KernowCooper]

It due to the inclined manifold mounting and common see my text above just get the blanking plate and your sorted.

Its because air is drawn in the choke via the air filter in that housing taking with it fuel with it from the float chamber, its crude really.

Edited by KernowCooper, 11 April 2013 - 05:40 PM.

[Hegnirst]

It due to the inclined manifold mounting and common see my text above just get the blanking plate and your sorted.

Its because air is drawn in the choke via the air filter in that housing taking with it fuel with it from the float chamber, its crude really.

lolololol will order one now :) thanks dude, the other thing is why do you think ithe engine would bog a lot when cornering?

[KernowCooper]

Maybe someones had the problem before and tried lowering the float lever to try and cure the choke leak?

[Hegnirst]

Maybe someones had the problem before and tried lowering the float lever to try and cure the choke leak?

possible chance
why do you think the engine would bog a lot when cornering?

[KernowCooper]

Fuel Starvation. Low float level ?

Edited by KernowCooper, 11 April 2013 - 11:19 PM.

[Dusky]

Thread revival

So just fitting that blanking plate is enugh to cut off the cold start mechanism?

Tempted to fit one as I'm not going to use it, and I have a pin hole in one of the 'cold start pistons'

 

cheers