Dellorto 40 Drla Problem

[tdr_1976 41 1 Cars]

Good evening all,

 

Last week, I fitted twin 40 Dellorto DRLA onto my 205 XS, using the standard lift pump to supply the fuel.

 

Today, I took the air filters off to check that everything was tight and still in place, and I found that one of the port butterflies on the drivers side carb had a pool of fuel on it, and was still dripping fuel into it.

 

The carb on the other side is fine, no problems at all, even after I've checked it five times in a row.

 

Once it's stopped and you restart it again after a small while, the excess fuel causes it to misfire.

 

Any help as to how I can remedy this would be most welcome, as I'm not to hot on how these carburetors work!

 

Cheers in advance!

 

Edited June 21, 2012 by tdr_1976

[johnnyboy666 195 1 Cars]

could possibly (don't quote me on this but similar can happen on some carbs) the float getting a tiny hole and slowly filling with fuel, so not resting at the correct level

[tdr_1976 41 1 Cars]

I suppose so mate, I've been trolling through Google to see what that brings up, not much to be honest.

 

My biggest fear is opening up the top of the carb to look and potentially disturbing the settings of the carb, as they work fine when the pool of fuel has cleared up!

Edited June 21, 2012 by tdr_1976

[johnnyboy666 195 1 Cars]

definitely not a sticking throttle cable?

asuming you dont change any of the jets or emulsion tubes etc, they should in theory stay pretty much as they were I wouldve thought. At least with dhla's I seem to recall being able to access the floats without disturbing much

[tdr_1976 41 1 Cars]

I've got an extra return spring on both carbs (For MSA Regs), so the throttle cable shouldn't be open in theory.

 

I've found various forums on google that have wide and varied ways of preventing it from happening........ HELP...... I Truly am Lost now.......

[allye 530 3 Cars]

porous float or a hole in the float sounds like a very plausible diagnosis and something I investigated when I had a problem with one of my carb'd engines. Easy to test if you can get to the float without too much hassle!

[tdr_1976 41 1 Cars]

I don't think it'd be a problem to get to the float looking at this exploded view diagram;

 

[tdr_1976 41 1 Cars]

Been busy earlier, I took the top off the misbehaving carb and had a look at the needle valve and found this;

 

 

 

Would this be enough wear to cause the fuel to drip into the port?

 

I also re adjusted the float and is now 5-6mm closed and 12-13mm open, as per Dellorto's Manual.

 

Cheers!