Hi guys, I need the float height settings for a DMTL, its the 32/34. I messed it up whilst removing the top cover... I have searched and have found that the gap should be 7mm between the float and body inc gasket BUT what is the droop setting (which you adjust with the tab by the pivot) I need the car to get to an exam in the morning, so as quick replies as possible would be ace. Cheers Rich
Not sure about droop but heres how I did it, it's ben running very well ever since, plugs just the right colour etc; First familiarize yourself with the tab/valve mechanism. hold the top of the carb with the floats swinging free and rotate until the tab touches the ball on the valve, if you turn it further first the cylindrical body holding the ball will move in, when this reaches its stop further rotation will move the ball into the body, this is simulating the effect of petrol moving the floats. The correct position is, as far as I know, when the body has moved in and reached its stop but before the ball has started moving in. I set my DMTL up by getting a 7mm drill between the top of the float and the body & gasket, then bent the tab/float arms until the valve was in the correct position. You'll need to sit down and fiddle with it for a while as its a bit tricky to get both floats in the 7mm position as well as the valve as described. Hope that helps and good luck with the exam, I've got one tomorrow as well.. maths god knows why I'm even on here, should be revising really!
Thanks That certainly helps a lot for the top setting, when the cylinder moves in, and setting it to 7mm in that position... But when letting the floats drop down to their lowest position (as if there is no fuel) what should the distance be in relation to the valve (maybe so that its at the bottom of travel?) or in relation to the float to top cover (for example its 25mm on twin 40's) So that i can adjust the tab by the pivot (not the one connected to the valve) to not let them drop any further. I'm pretty bad at describing what i mean, hopefully you can see what i'm on about...?
I'm not sure about that, I didn't pay any attention to the other tab when I did mine, not sure how important it is since you seldom have no fuel in there, if you look how fast the mechanical fuel pump delivers fuel I doubt the float would ever get particularly low during normal operation?
When the float is set at 7mm, it should be letting fuel through the needle valve, if the fuel rises (and reduces the float gap) the fuel should stop coming through the needle valve. So you need the float tag just touching the needle valve ball bearing when the float gap is 7mm. The other tag should just allow enough movement for floats to drop slightly, but not enough for them to droop into the bowls. If you bend it enough to allow a large droop, it will foul the carb body when you put the lid back on and hold the needle valve open constantly.
Well i've set the droop to about 18-20mm and it seems ok. The new problem is that if i drive with anything more than small amounts of throttle the car soon loses ALL power. Like a blockage or complete lack of fuel. If you leave it a couple of minutes it can be fine, or get out and blow some compressed air at the jets. I left the pump off when it lost power (electric pump) to check if it was that the fuel bowl was empty, but then after about a minute of it being off it started back up... My theory is that as i put my foot down, more fuel is being sucked and therefore sucking in something to block it - but i only cleaned the carb out a couple of days ago. How much loss of power does carb icing give, and would it be likely to only happen when i open the throttle more? Christ i miss the twin dellorto's
If I get icing in my Weber its either just slightly noticeable or an immediate complete loss of power in which case I have to pull over for about 2 minutes and wait, then it's fine again.
as far as i'm concerned the float level should be 8mm and not 7. as for the "droop", the haynes weber manual doesn't say anything about that.
Brillaint info , im having loads of problems with mine and icing up , even done it today and its been mega hot ? the side of the carb was stone cold , but i think maybe the amount i ported and polished my GTI head that when im floored maybe all the air rushing in from the cold feed near the wing is the problem , So im going to rebuild my carb as the gaskets are all done four , i've had to increase the CO levels alot to get it to rush stable and less voilent it seemed, Joe
I dont think so , whats that ? i've still got the carb inlet manifold heater in place, some evenings it the best thing ever it wont carb freeze , then some times it does IE today ? maybe the air was abit moist , coz i've been out on winter evenings floored and pulling 6k revs for long time so that amount of cold air going down there should be insane in term for icing up , Glad i've a VR6 on the bench at home , so i dont have to put up with a carb in the winter , even with that vacum airbox thing to allow exhuast heat to go to it , i've jamed that fully open and i can usally get around with that , Joe
Pictures from here, thanks to Nordoff Bracket for it going onto the base plate adapter It's the little black cylinder in the middle of the plate, with the thick black wire coming off it With the carb in place It's part of the original Pierburg carb, when the Weber is fitted it should be swapped over. The wiring should be there for it provided it was always a carbed engine.
IIRC, it's called a Throttle Body Heater. I swapped mine over when I binned the Peirburg on the Syncro last year. Drove it around all winter with a K&N open element filter with no problems at all. I'm thinking that this is the key to avoiding carb icing, not the warm air flapper thingy in the airbox.
