I think I broke my carb

[Dave-R]

I take it this is a Carter carb and the needle things are the metering rods?

The springs on the rods have to match the manifold vacuum. Like a power valve in a Holley. Not enough manifold vacuum (usually due to a bigger than stock camshaft) will open them up and flood the engine. You need to fit lighter springs so they only open when the engine really needs them too.

[Trigger_Andy]

Dave you cheeky Mugger! No, I never touched the damn thing, ever.

[Dave-R]

I am thinking you mean these two metering rods (called step-up rods here) which are part of the enrichment circuit that delivers more fuel when manifold vacuum is low.

[Dave-R]

Where is the fuel coming from?

If it is from the main jets it sounds as if either the inlet valve on the fuel bowl is faulty,
Or the float has a leak in it,
Or the fuel pressure is too high.
Or it could be what I said to start with which is that the two rods are not seating because manifold vacuum is too low.

[Anonymous]

How does the piston get manifold vacuum, Dave (Robson) ?

Is it through a port in the carb body into the manifold ?

Could it be that this port has got blocked (bad gasket, bad workmanship ).

Does anyone have an exploded diagram of the carb ?

All the best
Sandy

[Anonymous]

Hi Dave (Scott),

I have found my Carter carb book.

I will bring it round next week.

All the best

[Anonymous]

Hi Dave(s),

Had a quick read of the Cater book, plus, dug out Linda's Monaco service manual.

Here is the relevant section.

(depending on work, I will try and pop around tomorrow, lunchtime-ish).

All the best

[Anonymous]

Dave,

Just another quick thought. You know that hole you 'blocked' on the fuel pump ? Unblock it and see whether it runs better. Just in case it is some sort of vent and, with it blocked, the fuel pressure supplied to the carb by the pump is too high and it is overpowering the needle and seat and float.

All the best