leaking carburettor

[bootlid]

carburettor has at last come off for examination,found cork seal broken at three places,this seal was recently replaced new,what could have damaged it so??.

[MarkyB]

Overtightening?

[Neil MG]

Overtightening?

That would be my guess too!

[bootlid]

That means the petrol leak will still be evident again even after fitting new cork seal just as before,i tightened up the large nut below the body of the carb which only made the leak worse,may have to scrap carb. and purchase another h1 type as everything has been tried but the leak always persists.

[bmcecosse]

Use something better than 'cork'! May be able to modify a fibre washer for the job?

[mike.perry]

You may have to soak the cork in oil or something?
The choke lever on my H1 is damp but not actually dripping, not enough to risk taking it apart.

[bootlid]

worth a try,i,m waiting on report back from person stripping carb.

[bootlid]

carb. now stripped and report is not good,butterfly is excessively worn allowing air to enter carb,. the upper jet bearing appears to be of a less circumferance than it should be ,this allows petrol to leak down to the brass adjusting nut below carb body,what do the experts think?? maybe be better to look out for a better carb if i could locate one.

[bmcecosse]

I wouldn't worry unduly about the 'butterfly' (in fact - it will be the shaft, not the throttle plate, and the holes in the carb body that may be slightly worn) -this is easily compensated out at idling. Or bush them and make a new shaft - ideal job for a model maker! I seriously doubt the 'upper jet bearing' is worn - why would it be - it hardly ever has any movement against it - only when the choke is pulled. Any other H1 you find these days will likely be equally worn. Just find something better than 'cork' to make the seal.....

[bootlid]

Thanks for reply,i,m hopeless at making anything,my modeling is restriked to basic stuff,i,m not in possession of my carb. at the moment but my friend says the upper bearing in his mg has no spaces around in which for petrol to escape and is a tight fit where mine is a loose fit,what do you suggest instead of a cork seal??.

[DAVIDMCCULLOUGH]

The one that was fitted to my sidevalve was very worn at the butterfly and you could set it up to run nicely, then when you went to drive it it wouldnt tick over and would stall. Really crap especailly if your still running the old carb with the float beside the exhaust ....... A carb rebuild kit can be bought that includes bushes for the butterfly and all replaceable bits, I got one from ESM but then got a different carb off ebay that was like new and made the car so much more pleasant to drive. Still slow like!! Anyway a series 11 carb will fit a sidevalve and should be more easily found.

[mike.perry]

You will have to swap the float chambers as the Series 2 carb is semi downdraught.

[bmcecosse]

Your MG friend is comparing your carb with a newer model - different construction. You can if need be rebush the throttle shaft - and probably get a new shaft from Burlen - even if it's a different model... but this is not your main problem so don't worry about it for now..... Fibre or rubber seals instead of cork ?

[bootlid]

Thanks for all replies,i will keep in mind all suggestings,i received my carb. back today and fitted it to my mm,so far no leak,what was fitted was a replacement cork seal,i thought that the series 11 803 engine carb had horizontal manifold stud fitting.