Misc: Carburettors Amal Carburettors Dripping Badly
- Thread starter danno
- Start date
The position of and angle of the float bowl is my go to number one thing.
Your looks to far forward in the wee picture.
I set up with bike on the level, get the float bowl at 90 degrees to the carb body and sitting level with the level ground.
By loosening and twisting the carb you can get it leveled up.
Moving the float bowl fore and aft you can achieve a level set up.
Adjust fuel pipe feed to suit when set.
Then fuel/float level,I set fuel level just below the air mixture screw.
No fuel leaks from the overflow hole, sorted.
Al
Your looks to far forward in the wee picture.
I set up with bike on the level, get the float bowl at 90 degrees to the carb body and sitting level with the level ground.
By loosening and twisting the carb you can get it leveled up.
Moving the float bowl fore and aft you can achieve a level set up.
Adjust fuel pipe feed to suit when set.
Then fuel/float level,I set fuel level just below the air mixture screw.
No fuel leaks from the overflow hole, sorted.
Al
Well, only thing i can say reading all this, and having them on Atwin.....
Is:
MIKUNI.
Is:
MIKUNI.
Oh yes an "A" twin would look great with Mikuni's on it........along with upside down forks and twin disc brakes........if you want that kind of perfection, then buy a modern bike in my eye's..........the older the machine the more they drip and leak.......
Does a Mikuni float chamber work satisfactorily when fitted horizontally?
No problem fitting an Amal Pre-Monobloc with reasonable downdraught, even with an "incorrect" float chamber. That 600 cc 4V Horex was put on the road 20 years ago , never cared about finding a float chamber for this orientation. Just take care for correct fuel level inside and it never drips in normal use. When parked you certainly don´t leave the fuel tap open for hours - that would not work on most carbs, even modern types, without some dripping or even filling up the engine. Incidentally that Amal on the Horex was from all the Rapide boxes I got decades ago but never planned it for the Vincents. Lapping in the float needle is all you have to get right and no troubles then. Remember, the float is weightless in operation, as - well - it floats. And another argument: I guess you will do steep hill climbs or downhills, so what will the float think about these angles ??
Vic
Vic
Vic, if you own Paul Richardson's book "VINCENT" turn to page 194 and my comment will make sense to you, if you don't posses this book I will attempt to explain, unlike the post war twins, on the Series A Rapide, due to the lack of available space, the carburettor body is fitted horizontally, not vertically, of course a standard float bowl cannot function when fitted 90 degrees off the vertical, but with a remote float this can be catered for, but that is not so simple with an integral float chamber like that of the Mikuni VM Series, it would not be just a few degrees off the vertical, not just like going up an incline as you suggest, but 90 degrees off the vertical, that is my point.
Last edited:
Peter, you are certainly right, for carb body horizontal you´d need separate float chambers, a concentric like the Mikuni would not help. And I cannot see then how Vincent Speet can put some on an A-twin with minimal space available as you pointed out.
My posting about "uncorrect" float chambers is aimed on some who believe that amount of angled float like in my photo would not work at all or drip - which it does not.
Vic
My posting about "uncorrect" float chambers is aimed on some who believe that amount of angled float like in my photo would not work at all or drip - which it does not.
Vic
On float arrangements, it obviously has some range at which it will work fine, no different to a concentric, Mikuni, Dellorto or any other under bowl design of carby.......even total down draft like on an Aermachii......however on some carb designs the float position is more critical.......On the French Godet Grey Flash we took to Goodwood last September, the 42 mm Dellorto SS1 with matching remote float bowl needed the bowl mounted to the rear........this was due to the pilot jet arrangement to the rear of the carb body.......on heavy braking, the forward momentum of the fuel would starve the pilot jet, thus when blipping the throttle on down shifts, the engine acted like the ignition was turned off.......nothing there......so by moving the bowl aft of the main carb body, this helped to overcome that issue.......That took some head scratching I can tell you........Cheers.
I have seen 90 degree float bowl adaptors for Amal Mk2 Concentrics, though I think that is for vertical, not 90 degrees horizontal.