25 replies to this topic

[tomtic]

Yeah, checked, nothing's snagging the linkages. How would I 'give it a tune' and how do I know if the vacuum is working on the carb to make the piston rise? As I said, i've completly rebuilt the carb aswell.

[1984mini25]

The way I've been tuning mine to run properly is....

With the engine running (full warmed up) lift the piston-lifting pin till it hits the piston and then a further 1 mm on the side of the carb and listen to what happens,
If it cuts out the mixture is too lean, if the idle increases the mix is too rich and if nothing happens the mixture is about right.

The Haynes manual goes into much more detail, Pages 4A .15 and 16 fuel systems.
But at least you can get some near right for it to run smoothly

[tomtic]

Right, will have to give it a tune. I was just wondering, if gungum goes rock solid, I won't have any problems with it cracking will I with it being in a moving joint?

[Dan]

Possibly, that's why some people don't like it. I can't remember the name of the stuff I use but it's more like a thick white paste and it doesn't actually set. I'll have a look in the garage and tell you what it is.

If you've re-built your carb you need to start tuning it from the initial position. It's all listed fairly well in the Haynes but if you need to know anything else I'm sure someone will help.

If the piston and vacuum chamber are originally a pair (they are matched to each other for a good gas seal) and not horribly worn and you haven't covered up any of the holes in the filter mounting flange then the piston has to move. Leave the dashpot cap fully loose and blip the throttle and you should see the dashpot piston jump up. It won't work properly with the cap unscrewed but it'll show you that it moves.

[tomtic]

Alright, that's probably worth a try then. I rebuilt the carb, new gaskets, new jet, new butterfly valve, new float needle/valve.

I hope this gungum stuff does the trick, it was damn hard work sealing that flange in the exhaust without taking the carb off and disturbing the new gaskets. The main problem was tightening up the clamp with 2 spanners.

[tomtic]

Damn, tried re-tuning the carb, no luck.
Having the same problem as this guy: http://www.theminifo...opic=12296&st=0

I'm not sure what the problem is, I've replaced the jet and the needle valve in the float. Does the needle valve in the float need setting up? I've done as the manual says to set up the jet, but it's not changed anything, the car still splutters and dies when i try to accelerate, it feels like when you touch the accelerator at idle it just suffocates it. At fast idle the car will rev fine though!

Really odd, not had my mini long and it's dying already :'(

[Dan]

You have put oil back in the dashpot right?

[Mini Mad James]

You mentioned you changed the fuel pump, that might be causing your probs.

I remember when i first got my mini if the fuel tank was low my mini used to do exactly the same thing and i could only drive it with the choke on or it kept choking badly and dieing, i had my fuel pump replaced and it solved it, try driving your mini with a full tank of petrol and see if it still does the same thing.

[tomtic]

Yep, the dashpot is topped up and it's got atleast half a tank of fuel in, had 3/4 in yesterday when it was doing it. The fuelpump was changed yes, it's a new one I bought from minispares.

[Mini Mad James]

The fuelpump was changed yes, it's a new one I bought from minispares.

You sure its working properly

[tomtic]

Not sure how I'd check, it seems to work fine with choke and that, and once I'm at high revs cruising along. I'm just wondering if it's the float valve, if it's cutting off too early, it'll make it difficult to draw fuel right?