Engine revs high with throttle fully closed ..

[1608]

The lead will make the float sit lower and cause rich running. It may have been put there to ensure that the tickler reaches it. I have come across differing lengths of tickler.

[clanger9]

once it's all reassembled I'll see about checking it but would like an opinion on the float (above)

Yes, the solder has been placed there in an attempt to adjust the float level - probably because a thick washer was (incorrectly) fitted to the fuel inlet union. Raising the needle land in this way would lower the fuel level in the float chamber.

Regardless, you just need to set it to the right level (either by removing the solder or changing the washer(s) under the fuel inlet union). The float level is the first thing to check on an Amal. If it's wrong, then the carb won't work properly. The fact that your float cover hasn't got a pip on it suggests the PO didn't care about setting the float level correctly...

[Mick D]

Hi

I've not seen that blob of solder before and I doubt that it's original. I'm pretty sure original carbs were not designed with fibre washers between the float seat and carb body, fitting a washer effectively raises the level in the float chamber so the blob of solder may have been a counter measure.
Replacement carbs have a washer there, (part number 14/175 - about 0.5mm thick) and I have to assume the associated components are adjusted to maintain a correct fuel level.

Moral of the above - don't assume you can mix and match old and new components

The 'pip' is located centrally fore and aft and 31mm up from the bottom of the float chamber cover.

Regards Mick

[robcurrie]

somewhere I have read about the thickness of the fibre washer under the float needle housing / fuel inlet .. the one I have is quite thick, which may account for a high fuel level??

Early monoblocs shouldn't have any washer under the needle housing, modern (meaning new ones you can now purchase) have an aluminium washer under the needle housing.

Rob C

[Taid]

Hi

..............
Replacement carbs have a washer there, (part number 14/175 - about 0.5mm thick) and I have to assume the associated components are adjusted to maintain a correct fuel level.

Moral of the above - don't assume you can mix and match old and new components

The 'pip' is located centrally fore and aft and 31mm up from the bottom of the float chamber cover.

Regards Mick

I have a new float needle which appears identical to the existing (seems to have a neoprene? point on it ,,) ....

presumably this then would require the thin washer you mention, do you think?

Ah well, I suppose it will become clear when it is back on and I check the fuel level .. but would half a mm show when checking?

[Mick D]

Hi

I'd just re-assemble without the washer and check the level, if it's too low adjust the blob.

Don't forget the small brass spacer after you fit the float

Regards Mick

[Taid]

Hi

..............

Don't forget the small brass spacer after you fit the float

Regards Mick

Being the inpert that I am, I dropped it among the detritus on the garage floor as I took the carb apart .. "Oh gawd!! thinks I .. but someone was watching over me, I moved a bit of rubbish and there it was .. floor now cleaner ......

[Duncan]

somewhere I have read about the thickness of the fibre washer under the float needle housing / fuel inlet .. the one I have is quite thick, which may account for a high fuel level??

Early monoblocs shouldn't have any washer under the needle housing, modern (meaning new ones you can now purchase) have an aluminium washer under the needle housing.

Rob C

It gets even more confusing as Amal gasket sets include a washer that is not required on the original monobloc, owners who don't know this fit it as it in the kit.

[JEAN-NOEL]

In my opinion, even if the float level is incorrect, it does not explain the problem : rich or lean, the mixture needs a rather hig amount of air to make the engine running so fast ! 40 MPH in top gear on a M16 = at least 3000 RPM or so. The pilot jet circuit is tiny, and the tick over screw is here precisely to open very sligthly the throttle slide to give a smooth tick over. In these conditions where could pass the sufficient amount of air to run so fast the engine ? Remember : previously the bike runned fine on tick over, and suddenly the problem appeared, starting the engine e few days after. So, it is not wear, or defective mixture the culprit.

[SPRIDDLER]

Hi
The 'pip' is located centrally fore and aft and 31mm up from the bottom of the float chamber cover.

AMAL pip.jpg