Outer Limits 4x4 Board

my 1.3 is starting to use more and more fuel and blowing more black smoke. i did a compression test and all cylinders were on the 175 mark. my spark plugs are fouled up with carbon real bad too. i think if i change the air fuel mixture it could help a fair bit. i think it's running really rich.
1. can someone tell me where the mixture screw is? and what possibly adjust it to?
2. what is the standard position for the screw?
the engine has had most of the polution gear removed. the air is traveling straight into air box, and it's got extractors and a straight through exhaust if it makes a difference.

what does everyone here think i should do?
any other suggestions and comments will b appreciated.

If your plugs were the cause one would think it would also be running rough.

Is it running rough??

Smoke is never a good thing.

it's running really smooth, i can't complain about that at all. i put these plugs in anout 8000km's ago every time i have checked the plugs they have been black and sooty.
i just went out and got some carby cleaner, so i am goin to try that as well and see if there is any difference.

Is it a bit "doughy" at lower revs/ take off ? Slower than normal to pick up? If it is running rich it will be like that

I'm having the same problems as yourself, but mine is running really rough. I've had a mechanic pull down the engin and rebuild the head and that didn't help coz he broke the metal part of the pollution pipe running into the carb. Have bloked that now but hasn't fixed the problem.
From what I can tell the air/fuel mixer is on the engin side of the carb which makes it very difficult to change.
Just so you know if you have changed the intake and exhaust it will increase the air flow and not the fuel, which would make the engin lean not rich.

Let me know how you go because i'm sick of of getting 400km to 60L.

Black smoke means unburnt fuel.
In a petrol engine this would mean that you ar running too rich.

I would check that the auto choke was not sticking, or the butterfly in the primary venturi was fully opened when the engine is at operating temp.
Another problem could be that the float level in the bowl is too high - this will make the fuel mixture richer.
If none of that works, get a price on another carby maybe or get a kit put through it.
Best bet with the carby kit would be to get a carby shop to do it - I sure wouldn't try to rebuild a carby myself - you can always take it back if you have problems if it stuffs up later when someone else does it.

i've cleaned the carbon off of the spark plugs and put some carby cleaner through the carby. there was a lot of crap visible in the carby, it now looks alot better.

mj, i'm not sure what u mean by "doughy", but i can't complain about the way it is running. i've been driving alot of new cars around lately so it feels gutless but compared to new commodores it is. so i can't really tell if it is slower then ususal.

DeWsE, i'll chech out the mixture screw tonmorrow and see if i can find and adjust it. i haven't had the exhaust changed, it had extractors and straight through exhaust when i bought it, and that was almost a year ago. last time i filled up i got 150 kms out of 25 litres of fuel!!! and i had been very easy on the throttle the whole time.

No Idea, i agree the black smoke and carbon biuld up on the plugs shows it is running rich too.
i think the auto choke is alright as on a cold morning it will idle at about 2500rpm and drop to about 900rpm after it's warmed up. i'll try and check the autochoke,butterfly and float levels tomorrow.

i hope something works.[/quote]

get the carby rebuilt , built heaps of these before, it will either be the choke blocked, the power valve stuck on or the needle and seat not sealing \ wrong float level