Xs Carb Help

[M_R_205 5 1 Cars]

hi everyone

my litle xs trys to cut out when i put my foot down, only happens when i slam my foot down and not when i do it gently,

 

im thinking maybe the mixture is a bit lean??

 

How do i increase the mixture? or does anyone else have any idea what else it could be?

 

its a solex twinchoke carb with `performance` filter, and all the plugs leads cap arm etc are new so the carb is all thats left.

 

Thanks

Paul

[josh1990 0]

Me thinks the mixture screw is on the very base of the carb Back left, little hole you wont see the screw long terminal driver should get him, Also remember only to adjust this when the car is up to temperature. As the idle adjustment is on the throttle cam. Btw dont go mad litlle adjustments can change alot

 

 

Hope this helps.

 

Josh

[M_R_205 5 1 Cars]

Cool il try this, does my problem sound like its the mixture at fault?

 

EDIT: incredibly stupid question, which way to i turn it to richen? clockwise or counter??

Edited January 9, 2008 by M_R_205

[trogboy 17]

Before you go altering the mixture you ought to check that the accelerator pump mechanism is working properly. This supplys an extra jet of fuel into each barrel of the carb on rapid throttle openings.

 

To check you need to remove the air filter from the carb. Manually snap open the throttle so that both butterflies are wide open. You should see two streams of fuel ejected from the small brass tubes which project out into each of the barrels. These should last a couple of seconds (hard to remember now). The brass tubes are the accelerator pump jets. If one or the other (or both) is blocked this will lead to a lean spot before the main jets circuitry kicks in.

 

To unblock them you need to first get them out. This mean taking off the top of the carb - this will reveal that both of the jets are plumbed into a single brass jet holder that sits in the body of the carb. You have two choices here 1) use a small screwdriver the lever out the jet holder by prying under the jets close to the body of the holder or 2) use a pair of needle nosed pliers to grab the jets close to the holder and slowly wiggle them out by rotating and pulling. Both hethods have their drawback but I find that no. 2 is better as you'll find it more difficult to defore the jets and the locating holes in the holder which are just a push fit.

 

Once out try and blow through the jets - if you can't the're blocked. I used to find copper wire best for cleaning them out especially as it is softer than the brass. Using a pin can enlarge the jet hole which is not good as it will alter the metering of the fuel.

 

At this stage check that the accelerator pump is working ok. Manually moving the lever that runs off the cam on the far right hand side of the carb should send considerable volumes of petrol gushing into the main barrel from the holes in the jet holder. If you get no sucess try taking out the jet holder - beneath it should be a ball bearing which acts as a non-return valve. Check this is loose. If all seems ok it could be crap sitting in the fuel passage ways or, less likley, perishment of the diaphragm in the pump itself.

 

Ta da! Bet you didn't expect an answer this long - I certainly didn't expect to write one.

 

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[M_R_205 5 1 Cars]

To check you need to remove the air filter from the carb. Manually snap open the throttle so that both butterflies are wide open. You should see two streams of fuel ejected from the small brass tubes which project out into each of the barrels.

 

Your a legend, i could kiss you

 

When iv been playing with it and scratching my chin i dont think iv ever seen these jets of fuel, i know what you mean as i remember seeing them on the carb fitted to my original 1.1 engine

 

Il double check this tonight and pull the carb off and set about cleaning bits of it,

 

Thanks very much!

Paul

[M_R_205 5 1 Cars]

well, iv got the carb apart and i have the accelerator pump jets out and i cant blow through them , nor can i find anything small enough to clean them with, iv got some wire in from the end thats pressed into the colder but it wont fit round the bend at the end of the jets, any ideas what i could do/use? iv got them steeping in coke atm see if that helps dislodge some crap..

Paul

[trogboy 17]

I find that old multi strand wire like bell wire or old electrical wire is the best for the job. pretty much any old domestic electrical cable should do the trick (PC cables/old flexes etc). All you need is a single strand of wire. I'm afraid that is my only suggestion.

 

Even when they are unblocked it they will still be hard to blow through as the hole is so small. You shuld be able to tell though.

 

Good luck,

 

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[M_R_205 5 1 Cars]

Well i got to work this morning and managed to use a single strand of mtb brake cable lol,(not much work going on around here!!) i found the coper stuf was bending and no (oh my ) the dirt, i can now blow through them and with it all back together manualy twisting the pump makes a puffing/squirting noise which it didnt before which is good

 

Il fit it to the car over the weekend and let you know if it fixed the problem

 

Thanks again for your help

Paul

[M_R_205 5 1 Cars]

hmm i mis typed the above post and cant fid the EDIT button "i found the coper stuf was bending and no (oh my ) the dirt," is ment to read.... i found the coper stuf was bending and not penetrating the dirt,

[M_R_205 5 1 Cars]

thats fixed the acceleration problem, goes like stink now

 

All i have to do now is sort the rough running out.... tough its booked in at a RR tomorrow

[Guest OldGit]

really low rating fuse wire works ok if you're careful too. as trogboy says, most wires are tougher than the brass jet so extreme care is needed or you may end up needing a new one... .

 

for future reference for anyone scratching heads about direction of mixture screws, these are basically cone shaped blocks that get wound into a pipe, so that the further in the block, the less fuel can get past. therefore, loosening (anticlockwise) is richer, tightening (clockwise) is leaner. always. even for voodoo SU's and the like (shudders)