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Amal Monobloc float valve


Well Known and Active Forum Website User
Non-VOC Member
When I originally fitted new monoblocs to my D during the rebuild, they had a washer under the float valve seating. After running for a while , I made up a perspex cover for the float chamber to check the level and found it about 1/8th high. Spoke to Amal about this who said that the level wasn't critical but that they did have shims to replace the washers or that the washers could be removed so that the level could be lowered. I ran the bike with the gaskets for the last 18 months with no carb issues. Last week I decided to check the sync on the carbs and whilst doing so decided to see what effect removing the washers had. I checked the front carb level with no gasket using the perspex cover. It was lower but about 1/16th high so I went ahead and removed the rear washer too without checking the level.
Started the bike , tick over rough with occasional 8 stroking which it had never done before and it would not respond to adjustment of the air screws. I packed in for the day.
The next day the garage smelled of petrol and the was a puddle under the bike from the rear carb. the fuel was dripping from the throttle stop screw. I thought the float might have stuck as they sometimes do, so tickled the front carb to start the bike and was rewarded with two fountains of fuel from the tickler which would not stop with the tap open ( my taps do drip slightly but don't leak externally).
When had checked the levels, I had only finger tightened the float seat, when refitting the fuel hose banjo, I used a spanner on the float seat and banjo bolt. This was sufficient for the float seat to move futher into the chamber so that the float got stuck on it.
The advice about the washers not being necessary on the new carbs appears on other forums and I have seen it here somewhere but can't remeber where. I my case it was bad advice.

Moral if it ain't broke don't fix it
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