Carburettor leak - well both now, actually !

[Kenny]

OK...offside carb started to weep a little where the cork gasket of the float bowl mates with the carb body. No problem there.

At roadside removed and re-attached..no joy ! Just to make sure the petrol levels were the same in both carbs etc ..took off the nearside float bowl and nipped the bugger putting it back on

Ordered three ( always like a spare ) cork gaskets from Motorworks which came today. Replaced both sides and STILL leaking at the gasket face

Everything is clean and not warped etc..should just be a simple action of replacing the gaskets and all should be well with the world

Had to stop as had a new knee before xmas and very recently spine numbers L3 L4 L5 and S1 have gone AWOL so bit crippled at the moment to say the least

Any ideas for a repair ?

Motorworks have kindly agreed to send two replacement freebie gaskets out to me but I don't think this will be the cure as currently leaking even trying all the three new ones today. Carbs arn't flooding and floats cut off as they should ( petrol is about 5/8th of an inch from the top edge of the float bowl when I remove them - pic looks a tad wrong as I spilt a bit posing for the camera )

Bike starts/runs/cruises at 100 mph if I want the R100rs to etc etc

Few pics....

 

[PW Cymru]

I know you say it's from the bowl flange but is it possible the supply tube is leaking.

I recently had very similar.

Just walk under the carb and lookup

 

[Ogmios]

Will i do, until an adult comes along?
If this is true;

... petrol is about 5/8th of an inch from the top edge of the float bowl

how can this be true?

... leaking at the gasket face

Unless the float needle in at least one carb is sticking open, allowing both bowls to fill and spill.

Oh - sympathy on the knee and back strife . Been there / got the codeine.

 

[Fanum]

Just walk under the carb and lookup

Harsh.





But funny

 

[Rob Farmer]

Those cork gaskets from motorworks are shite and seldom fit properly. Buy some genuine ones and see if it still happens. Motorworks need shagging for selling some of the crap they do. I've all but given up on them.

 

[Kenny]

Harsh.





But funny

I'm watching you m'laddie !

Gotta watch your back around here........

 

[Kenny]

Will i do, until an adult comes along?
If this is true;
how can this be true?
Unless the float needle in at least one carb is sticking open, allowing both bowls to fill and spill.

Oh - sympathy on the knee and back strife . Been there / got the codeine.

Weird isn't it? Both float bowls are filling up normally; cleaned both needles and jets but they are virtually new ! When I dried everything off then re-fitted bowls.....I can then see the leak at the joint faces ( both on inside side of each carb ! ) once some petrol fills into the bowls. The bowl over-flow pipe ( should the float needle not seal etc ) is clear and no fuel comes out from there, so not flooding etc.
Took float bowl from another airhead and that did exactly the same on mine...so not the actual bowls warped etc.
Fecked for the day now...normal cursing will resume tomorrow

 

[Ogmios]

Weird?
definitely.
Cant wait to find out WTF is doing it now!

 

[Rob Farmer]

I'm watching you m'laddie !


Rob, Motorworks tell me they are BMW gaskets....hmmmm

Maybe they've changed then but the ones they sold me were rubbish.

 

[Smug]

Check that your float levels are not set too high.

 

[snelly]

Weird isn't it? Both float bowls are filling up normally; cleaned both needles and jets but they are virtually new ! When I dried everything off then re-fitted bowls.....I can then see the leak at the joint faces ( both on inside side of each carb ! ) once some petrol fills into the bowls. The bowl over-flow pipe ( should the float needle not seal etc ) is clear and no fuel comes out from there, so not flooding etc.
Took float bowl from another airhead and that did exactly the same on mine...so not the actual bowls warped etc.
Fecked for the day now...normal cursing will resume tomorrow

Did it leak from the same place as the original bowl, or was it a different spot.

 

[Kenny]

Check that your float levels are not set too high.

This is the route I'll take tomorrow I was well dosed up with Naproxin and Zapain ( plus cough some other medication ) earlier so I'll pull out the bike ramp and attack her tomorrow with renewed gusto before taking any meds !!


Rob, you are right re poor quality gaskets..I also bought some of them a while ago....ill fitting and wider than the standard jobbies....but these latest ones do look correct

 

[Kenny]

Same....it must be the float heights just a tad to high !

 

[DrFarkoff]

Or possibly dirt tween the float needles and the seat !

How old are they Kenny Your tips may have gone hard ?

 

[Steptoe]

How old are the floats ?. They can lose buoyancy over time.

 

[Kenny]

Thanks guys...carbs have been rebuilt and tips look fine. No idea on age of floats but it is worth considering replacing them should the following not work. I'm going to fill the float bowls as normal...remove them carefully and then measure the fuel from the bottom of the bowls 'well' to the height of the fuel. If I remember it should be 24mm. Be better on my ramp and sober

 

[Smug]

When you drop the bowl the float will drop and more fuel will pour into the float bowl. Disconnect the fuel hose first.

Sometimes the floats split and draw in fuel which will also cause flooding. Take the float off and shake it to hear if there is any fuel inside.

 

[Steptoe]

When you drop the bowl the float will drop and more fuel will pour into the float bowl. Disconnect the fuel hose first.

Sometimes the floats split and draw in fuel which will also cause flooding. Take the float off and shake it to hear if there is any fuel inside.

BMW floats aren't hollow metal. They're a solid material.

 

[Kenny]

Well all sorted now.

Put bike up on ramp - much better for quazimodo to work on !.
Replaced fuel hose ( so I wouldn't have to grovel a thankyou to PW Cymru ). They were both wet ( I thought I'd replaced the fuel hose but that was on my other airhead )
Stripped the float bowls/needles/floats etc and cleaned/set everything ( set depth of fuel in bowl at 24mm mine were showing about 27 mm ). One needle wasn't clipped onto the tang of the floats. Floats seemed all OK
Put all back together again with replacement cork gaskets and all is well with the world although not test ridden her yet but no leaks
Good advice all round, thanks all.

 

[PW Cymru]

Glad your sorted,