Accelerator Issue

[petavius]

You make it sound like I don't trust you with my darling car......

[pettaw]

I've got to jump out quickly this evening, but I'll post you a full guide later on when I get back tonight, might be a bit late o'clock though. Its a fiddly job, but not too difficult.

[petavius]

Thats good of you, thanks Andy!

[pettaw]

Right, OK, first of all ideally I wouldn't have run the car for a few hours anyway, that'll make sure that the carb won't be too full.

Then what to do first of all is remove the choke cable from the carb. Make sure you mark the position of the cable inside the clip as this is used to set the choke cable setting. You can leave the fuel and throttle cable connected as you're not going to be taking the bottom half of the carb off and the fuel hose should be flexible enough.

Then remove the four allen screws holding the carb down and then remove the screws holding the float chamber lid on. Lift the lid very carefully making sure that the gasket unsticks OK and doesn't tear on anything. If it looks like its getting stuck in a certain position, then very gently run a blade or thin screwdriver along that part just to break the seal. Ideally you want the gasket to come away with the lid portion.

Once the lid is off, make sure there's no obvious dirt floating about inside the float chamber, unlikely because the car otherwise runs well. Then turn the float chamber upside down so the floats are resting against the needle valve, holding it shut. Get a tape measure and measure the distance between the tip (point) of the floats and the edge of the carb lid, including gasket. This should be, I think, 33.7 mm, but Haynes will confirm the exact dimension. It doesn't have to be too exact, but 34mm would be better than 33 If its not correct, then you need to bend the tag on the floats that rests on the needle valve carefully to adjust it.

Dai's test for the accel pump is a good one, hold the carb down to prevent it dislodgind, and then briefly move the accel linkages sharply, whilst looking down the carb barrels. You should see a brief, but quite sizeable squirt of fuel coming out of the brass tubes just inside the barrels. If so then the accel pump is most likely working fine.

Reassembly is the reverse of removal

Tightening torque for the carb bolts (long allen head types) is 14Nm, its fairly important to get to this torque cos too loose and you might get air leaks and too tight you may distort the flange and cause warpage.

[Chris_C]

One tiny thing Andy missed, is when setting the float height, make sure the tag of the floats is JUST resting on the ball bearing, not pushing it down. It needs three hands to measure, but theres 2 of you . Other thing worth doing if you have tiny scales is to take the pivot pin out, and weigh the float assy. Haynes has the number again.

Good luck!!

[pettaw]

good call on the weighing the float thingy. The float doesn't need to be just resting on the needle valve on the Solex IIRC, you can let it go in all the way

[CarlD]

Thanks for the information guys, looks like i will not be able to get on to it untill Saturday, but the fact i've got something to refer to makes me feel a lot more confortable.

Cheers
Carl

[foggyjames]

Before you get too engrossed (and bearing in mind that the weather isn't too conducive to long periods outside), it might be worth making sure that it isn't just running a touch rich or lean. I'd suggest that typically a pronounced (maybe even 'violent'?) hiccup would be lean, while a mild bogging / gutlessness is rich. Of course this can feel totally different on different cars, and only this weekend my 240 caught me out - it 'seemed' rich, but twas lean...

Of course the danger is that you adjust the idle mixture to cover up a another problem, so tread somewhat carefully! If it wants to go richer, I'd check for an air leak using the "blow lamp test".

cheers

James