16 replies to this topic

[miniman5]

Hi! we just went for a spin in silber :grin: at the lights it idals normaly but it you just tap the pedal itle drop right down to 500rpm or so and some times it cuts out all togeather dad thinks its a stick cable what you think?!

[Bluemini]

Could be...
Try giving the linkage were the cable connects to the carb a clean and a drop of oil. Also check the dashpot isnt grubby causing it to stick and that there is oil in the dashpot too.

[Dan]

Could be that, or low fuel level in the float bowl. Or general tuning.

If the throttle linkage is OK and you still suspect sticking, replace the cable rather than trying to repair it. They only cost around three quid and are easy to change and lubing them up is never fully effective. And if you oil the cable it only drips all over the carpet.

[miniman5]

we aitn got carpet in our at the front! the window seals on its way out n they were wet and smellly so we took em out!

i know whaere the dash pot is and stuff but how will i tell if its grumby i dont know what its ment to be like. i know you can unscrew the bit on the top to check. you can put red ex in there cant you? thatle clear it out! ile take some picys of what that dash pot dip stik kinda thing looks like

[Dan]

NO!

The dashpot wants nice clean oil in it only. Preferably dashpot oil if you can get any. That part of the dashpot is just a damper like your shock absorbers. The dipstick thing is actually a small piston which sits in the oil and damps the movement of the main carb piston. The bit which needs to be clean is the inside of the dashpot itself where the carb piston rides. The dashpot (called the vacuum chamber really) is held by two screws to the carb body. If you take it off be careful that you don't bend the carb needle or let any grime get around the carb body where the chamber joins it. Then draw the piston out of the chamber and check that the inside of the chamber and the edge of the piston are clean. Also check the inside of the piston where the spring lives, and the spring itself. Don't damage the spring. When you put it back together make sure the piston is the right way round (it has a groove to locate in the carb body) and then get the chamber lined up to its screws before you lower it over the piston and compress the spring. If you lower the chamber down and then twist it to line it up you will wind the spring up a little which will change its rate.

If you have to clean the chamber or piston, don't use anything abrasive because they have to fit together very well so that they are almost airtight. If you scratch the surfaces or wear them down you will damage the seal. Use meths and a soft cloth.

[TimS]

the dsh pot is the top part, withing ythe bowl shape thing. there are 3 screws holding it down. undo these and take it off! make sure that you dont bent the needle or loose the spring! THEN MAKE SURE THAT IT SLIDES UP AND DOWN EASILY.

[CharlieBrown]

I had the same problem and it was due to the fact that there was no oil in the dash pot, once there was some in there it ran fine.

[miniman5]

ok where can i get this from?? and how much should i put in?

[Bluemini]

I use either 3 in 1 oil or thin engine oil in the dashpot. Unscrew the black plastic top off the dashpot and carefuly poor the oil in the round tube indie the dahpot hole. When it reaches the top of the tube, thats enough.

[miniman5]

i took a picy of it erliyer but dads asleep so i cant put the picys on here :nugget: seems oily though!

[Dan]

The oil in the dashpot should come up to half an inch below the top edge of the inner tube that you can see when you look into the neck of the outer tube. But if you do put in too much the extra will eventually be drawn through the carb and burned off. But it is that which makes the vacuum chamber dirty and oily so try not to put too much in.

If yours has oil try the other things to do with cables and stuff.

Also, had a similar problem with a car once which was tracked down to a faulty coil. 'Theres no way it can be the coil' we thought, so it was the last thing we changed. I was shocked when it worked I can tell you.
But it is more likely to be carb related.

[miniman5]

what the ignition coil?

[Dan]

Yes, but as I said it's not likely to be that. Just bear it in mind if nothing else works.

[miniman5]

ok. here is the dash pot dip stick kinda thing. coverd in oil as you can see.

Attached Files

•  DVC00028.JPG   0bytes   0 downloads

[Dan]

Well, that's still not a dipstick. Just 'because it's got oil on the end it doesn't mean theres enough in the dashpot. It's a damper. Look in the dashpot and make sure there's enough oil there. You shouldn't be able to put the damper back in the dashpot without resistance. It should start to fight you just after it goes in the neck and resist all the way down 'till it settles.