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Mk2 amal flooding

john998

Well Known and Active Forum Website User
VOC Member
When I fitted the Mk2s to the solo the front one constantly flooded. After much head scratching the problem was fixed by cutting the ears of the float bowl gasket. These had been trapping the float spindle which was tight in the nylon float. To be on the safe side I reamed the pivot holes in the float as well.
5 years later the rear started to flood, so off with its ears too, it still floods, so change float bowl, float needle, and float, it still floods. Has any one any helpful hints? I see that there is something call a stay up float available any thoughts on that? John
 

dommy2

Active Forum Website User
VOC Member
Hi,
I run these on a couple of bikes & often get the same symptons.
I find to that a couple of taps with a piece of wood usually reseats the float needle.
I beleive this is caused by the DUFF petrol they sell on the forecourts.
 

john998

Well Known and Active Forum Website User
VOC Member
Hello, Just to say that I am using Viton tipped needles, and my first reaction was to tap the float bowl. The flooding was so bad that the motor was noticeably off song at low speed. Any one with experience of the stay up floats that Amal now sell?
Just fitted new 28mm Mikuni carbs on the outfit, one of which flooded on first attempt. Had to change the float needle and seat to fix prob. There was nothing obviously wrong with the parts removed, and the Mikunis have steel float needles. John.
 

Peter. C

Active Forum Website User
Non-VOC Member
I have been using Mikunis for four years on the Viscount and changed to Viton tip needles very early on, the rear carb is always the one to flood and on dismantling there is usually a bit of black petrol pipe inner on the seat. I have changed pipes to braided stainless type which causes less problems. To rectify the trouble I leave carb on bike, disconnect pipe, remove bottom plug to drain and give a gentle blow with air line down the feed pipe, this has always worked and saves a lot of time and
effort.
Peter.C
 

passenger0_0

Well Known and Active Forum Website User
VOC Member
The mk2 amals I run also tended to flood occasionally and at random intervals. The best remedy to date has been to use 2 bowl gaskets to give clearance between the upper face of the float and the underneath face of the body around the pilot circuit. Yes this theoretically will lower the fuel level by the thickness of the additional gasket but I measure mine with an external clear plastic pipe and could not detect any difference in fuel height. Tempering this is the fact that in my application I've got to use a fuel pump regulatated to 1.5 metres methanol pressure head but it might be worth checking that clearance exists between these two elements. Isn't half the fun of owning a classic the experience of traditional behaviour traits?
 

john998

Well Known and Active Forum Website User
VOC Member
Hello, It is the rear Mk2 that is flooding, but the front one was the first to play games.
Yesterday I warmed the float bowl and tapped the float valve seat inward 1mm, like using two gaskets this will
affect the fuel level marginal. So far it looks good, but the machine has not been road tested yet.
If this fixes it, the problem must be in the relationship between the needle length and the float movement.
Perhaps the fork on the float has bent slightly so not allowing the needle to seat, time will tell.
John.
 

norvin998

Well Known and Active Forum Website User
VOC Member
I had a similar problem with chronic flooding of the rear Mk 2 on my Rapide. After much dismantling and cleaning, only for the problem to return, i put a fuel filter in the line serving the rear carb only. This cured the problem completely. The rear carb, being the lower gets any silt thats in the fuel system. I couldn't see any silt in the float bowl during the stripdowns but it must have been there for the filter to cure it, the gauze filter on the petrol tap was obviously too coarse to catch it. For what these paper filters cost, I would suggest that you try this first before any more involved cures.
Good luck.
Les
 

Newbs1

Forum Website User
Non-VOC Member
Hi John,
I am a new member with a C series rapide fitted with two front heads and having two 2900 series Mrk2 carbs fitted on the left hand side of the bike. I had the same problem with flooding. I purchased the Amal "Stay Up" float kits part number AM/622/069A from my local Enfield dealer. You could purchase from Amal direct at Burlen Fuel Systems Ltd, Spitfire House, Castle Road, Salisbury, Wiltshire, SP1 3SA. Tel 00 44 (0) 1722 412500. email: info@burlen.co.uk web:www.burlen.co.uk. The kits come with full instructions and float height adjustment. My carbs had the earlier white plastic (Nylon) floats which could not be adjusted. The new floats have a stainless steel tang which can be bent to alter the fuel level. Adjustments to carbs were made may 1972, April 1974 and May 1986 (The final change). If you follow the Amal instructions it is easy to work out. Unless the float height is correct the valve will not close. I already had viton tips however for about £10.00 each float kit this cured my problem. Hope this helps.
Regards, Geoff


Hello, Just to say that I am using Viton tipped needles, and my first reaction was to tap the float bowl. The flooding was so bad that the motor was noticeably off song at low speed. Any one with experience of the stay up floats that Amal now sell?
Just fitted new 28mm Mikuni carbs on the outfit, one of which flooded on first attempt. Had to change the float needle and seat to fix prob. There was nothing obviously wrong with the parts removed, and the Mikunis have steel float needles. John.
 
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