6 replies to this topic

[joltfreak]

O.k. let me start from the beginning: my mini has been sitting around for 20 years when i bought it. when i got it home i gave it a quick tune up (oil & filter change, New plugs and wires, pumped out the old gas in the tank and put new gas in) and she ran! but she ran a little rough. since then i replaced the rad with a custom one, put a heavy duty water pump, new thermostat, new coil and electronic ignition, new fuel regulator & fuel filter and also replaced my old carb and intake (nikki) for a 1.5 (h4) su and intake. i also pulled out the wiring harness and replaced it with my own custom one with a new fuse block....now i can't seem to get it to run right. i checked for spark and i have it ... i turned on the fuel pump and i have fuel in the carb...i also checked and cleaned the float, topped up the dashpot, checked firing order on the dizzy and plugs, and reset the timing. I didn't change it all at once, it was over the course of a few months. first it was the rad and the cooling system was changed (last fall). but the car ran (rough but it ran) come spring the car wouldn't run...i checked the nikki carb out and found the fuel filter was caked with cr@p. i couldn't find much info on the carb and no one had parts for it. i checked the coil and thought it bummed out so i replaced it. i checked the wiring and noticed some cracked and frayed wires so i redid the whole wring harness to be sure. i checked the condenser and found the wire frayed so i put in a electronic ignition system (newtronic). so i picked up a used su carb and intake. i rebuilt it and put it on(i did fill the dashpot). i changed the plugs and installed it with a inline fuel filter. the car has an electric fuel pump and i noticed that i had alot of fuel in the carb ( it was pouring out of the carb) i checked and cleaned the float. still over flowing so i put in a regulator and gauge and set it @ 2-2.5 psi. i even took the carb to my local mini shop ( where i bought the carb and had him set it) . i check the timing and it was off so i set it (static) and it still won't run right it's running too rich . it runs for about 5 mins. than stalls out. i check the plugs and they are wet and black. the only thing i'm not 100% sure about is the needle...it's the one i got with the carb. so i ordered a new stock needle...i'll hopfully put it in this weekend. i'm also not sure how exactly should i "tune" the carb and that's where i'm at now.... any ideas???

[Pavel]

Which 1.5 su is it? There were two: HS4 and HIF38.

The HS4 will have the float chamber hanging on the side, the HIF38 has it underneath the carb.

Adjusting the HS4 is very easy. On the bottom, at the back of the carb, there is a nut that adjusts the jet. Turning that nut will make the carb run richer or leaner, (don't remember 100% which way is richer and which is leaner so I won't mislead anyone..).

As for HIF38 (which is a better carburettor, but if going to HIF carbs, most people use the HIF44 from a metro, which is the best SU carb you can get for your engine), I don't know because I haven't dealt with them much (although I do have one lying around downstairs...)

Also it might help some of the other experts around here if you give us your engine specs?

[joltfreak]

i have i 1976 mini 1000 canadian spec. 988 cc engine it's stock as far as i know. other than what's stated above it has a chopped intake and a header on it the carb is a h4

[dklawson]

Jolt, as I mentioned in your thread at M.Portal... don't give up on the float chamber yet. You shouldn't have had to add the regulator to prevent the bowl overflowing if the float valve was working correctly. I know you said the guy set it up right for you but this doesn't sound right. Go back and look at the fuel delivery to/in the carb before focusing on the mixture needle.

Your decision to go back to a stock mixture needle should be fine and may get you better running, but I doubt it will fix the plug fouling/flooding you're describing. Look carefully at the float valve adjustments. Consider using a Grose jet instead of the regular float valve and make sure the float arm/float are adjusted properly and that the float itself isn't full of fuel.

[philster]

sounds like the needle valve/float is faulty. If this leaks it causes the engine to run rich and rough and also pours out of the top of the float chamber/over flow pipe. Even if you've replaced the needle valve with a new one theres no saying its any good. I've had new ones with rebuild kits in the past and the old one has been better! Also check to see wether the float itself has filled with petrol if it has it won't float an therefor won't work!

[joltfreak]

the float is not filling up is set up right and the needle is working in the float bowl ....the only reason i put in the regulator is because my fuel pump was pumping at 4-4.5 psi. almost double what i should have. the carb hasn't over flowed since i put in the regulator and set it at 2 psi. but i'm still running rich :nugget:

[dklawson]

Well, just to be sure... start the engine and immediately cut it off. Remove the float bowl and check the level of fuel in the bowl. If you're going back to a stock 998 needle after this be sure and go through all the jet centering and setting adjustments. Don't just put the new needle in. Let us know what you find out.