Webber carb help!

[chasbaps]

Frodos not firing right, in fact hardly firing at all! Everything stinks of petrol, and I think the carb is running rich, but what screw does what? Looking from the drivers seat, on the left is the idle speed screw, then underneath that is another screw but I don't know what it does, and which way I should turn it! Then there's a big brass screw by the float, again what does it do, and which way should I turn it?
I'm there. Now, so I'll be hitting refresh and hoping that someone can answer!

 

[admin]

admin help

 

[chasbaps]

There you go! I'm talking about the shiny one running across the picture and the big one coming towards the camera.

 

[Panky]

I would guess the sprung screw at the bottom is the mixture screw - screw it in to weaken mixture.
Screw it all the way in and turn it back a turn and a half.

Summer's here.....
So they say

 

[chasbaps]

Thanks Panky! It was about four turns out, so that could help. Just waiting for the horse riding lesson next to the barn to finish, so I can try firing him up!

 

[Panky]

I've always found the turn and a half is a good starting point, I use a Colourtune plug to set it up after that. Failing that once its running turn the tick-over up slightly and screw the mixture screw out slowly until the engine starts hunting (too rich) then turn it in 1/4 of a turn and re-set the tick over, that should be pretty close.

Summer's here.....
So they say

 

[martin maltas]

The big brass one is the slow running jet. Won't stop it starting, but can affect idle if blocked

http://www.commervanspares.co.uk/

http://www.yorkshireclassiccampers.co.uk/

 

[commeracer]

Check the float for holes, and the float needle for seating

"You,re only supposed to blow the bloody SLIDING doors off"

 

[chasbaps]

Thanks all! Got him running, but still very rough and cuts out quite a lot. Need to have a bit more of a think...

 

[Panky]

Oops sorry Charlie[8)] I guessed wrong:I

Summer's here.....
So they say

 

[chasbaps]

No Panky, your guess was a good one, and the screw was about 3 turns too far out! It just looks like I need to check a few more things, next time I go up to the van...

 

[chasbaps]

quote:
Originally posted by commeracer

Check the float for holes, and the float needle for seating

"You,re only supposed to blow the bloody SLIDING doors off"



And how do you do that? :I

Does anyone have a manual for these?

 

[Enigma]

Hello Charlie...disconnect the throttle cable, choke cable, take the fuel pipe off and gently pinch it with a pair of mulgrips or similar, take the breather pipe off and obviously the air filter....remove the 4 bolts that allow you to seperate the top half of the carb (undo these 4 bolts a little at a time in a diagonal fashion) be careful not to damage the gasket in between the 2 halves, gently lift the top half off! check in the bowl for black gunge (snakeskin) rather than removing any jets, get a bike pump with a football nozzle and blow the jets through...do not try poking anything in the jets like a pin or needle as they damage easily...

If you haven't already done so, make sure you have an inline filter in the fuel line just before the carb (a good idea to have one between the fuel tank and pump aswell) Once you have the top half off, just check the float for holes and damage like Tim said (it will be obvious once you take it apart Then try setting it up again like what Panky said...hope that helps remember to put everything back again...when you put the 4 bolts holding the top to the bottom tighten them a little at a time in a diagonal fashion

''COMMER'EnSayThat''

 

[Enigma]

Also remove these 3 screws and carefully remove the cover...in side is a delicate rubber diaphram...check for damage/splits etc

''COMMER'EnSayThat''

 

[chasbaps]

COLIN!YOUR CARB IS BEING ATTACKED BY A FLOURESCENT SQUID!

Thanks for the tips, I've currently got two inline filters, a gauze one and a paper one, and the diaphragm looks ok, so I'll check the float today.

 

[chasbaps]

Well, I got up there and had a tinker...

The filter in the carb was full of crap, not snakeskin, just rust, paint flecks, splinters (?)

This is what I managed to extract

However, it doesn't seem to have solved the problem

I don't think its a jet problem - when I flicked the throttle linkage, a good strong squirt of fuel came out. I've adjusted the mixture using a colortone spark thingy, and that looks fine. The wierd thing is, if he is left for a while, he seems to run ok, then after 30 secs or so, starts to misfire, splutter and stall.

Anyone got any other suggestions, or I'll have to admit defeat and call the mobile mechanic (for the first time!).

I'm off to Turkey till Thursday for work, so won't get a chance to do anything until next weekend.

 

[chasbaps]

Oh! one other thing I noticed - there was fuel dripping out the bottom of the fuel intake bit - the big nut on the bottom, and I have seen fuel leaking out of the hose end, even though it has a tight jubilee clip holding it in place. This made me think that the fuel pressure may be high?

 

[Panky]

The fuel squirting into the carb is from the accelerator pump, it squirts everytime you hit the pedal to give it a bit of umph, the jet is seperate and you could have a blockage there. Try the old rev the engine and put your hand over the intake trick. The carb could be a red herring, the problem might be the coil breaking down or maybe the condenser in the dizzy.

Summer's here.....
So they say

 

[chasbaps]

quote:
Originally posted by Panky

The carb could be a red herring, the problem might be the coil breaking down or maybe the condenser in the dizzy.



OK, I'll get new ones of those for next weekend. Cheers for your help Panky - It really is about time you moved to Alton!....

 

[chasbaps]

By Jove! I think I've fixed it! The cloth wire in the distributor was badly frayed. I bodged a replacement with a very flexible bit of speaker wire and he sounds great! Thanks for all your help guys!