9 replies to this topic

[mpett]

Hello forum members,

This is my first time on this forum. I have been a member of the Westfield Clubs forum for the last year and it has proved to be a very entertaining and useful resource! From the posts I've read, this forum seems much the same.

I need your expertise in how to get a 1000cc mini engine running sweet but before the details, let me set the scene.

In November I set out to buy my gfriend a mini to replace the one she sold to go to Uni. I owned a mini at Uni, well before I knew anything about cars, so was looking forward to getting back into the mini scene.

In a week of searching, I identified a 1991 mini Racing green limited edition that had had a head gasket failure and a 1962 850 Austin Mini that a colleague at work was selling. We went to see the '62 first and my gfirend fell in love with her. The 850 was in really good nick for her age and it transpired that a full recon had happened in the 90's. The engine had only covered 3k since its rebuild and it had been garaged the whole time. It wasn't perfect, but I could see that it wouldn't take a huge amount of effort to get her into a good condition. So.... we bought her for £300!

Having arranged to see the Racing Green car already, I thought I'd have a look. In addition to the head, its sills were rotten and the driver's footwell had a nice rot/crack in it! So, £100 later I had her on the back of the trailer! :cheese:

Well, to the present day and my problem! The structural work is all done and the engine is running. I have two classic, highly rare things that happened to me in the rebuilding process which had me scratching my head and will have you laughing. Firstly, I got a dodgy sparkplug, which is a one in a 1000 occurance, and secondly, a split washer fell into the inlet port when I was re assembling the manifold which then got stuck between the valve and the valve seat. This led to no compression in one cylinder and a lot of 'what the f**ks!!!

With the above identified and rectified, I am now trying to set up the engine with nothing calibrated. The only thing I do know is that the timing sequence is correct. I have played around with the fuel mixture on the SU HS4 carbs so I think that is out too, but not by much. I've turned the adjustment all the way in then 15 flats out. (its running albeit a bit rich)

I've set the scene now, so here's the question. bearing in mind that the setting of the timing is slightly out (set by ear for the mo) and that the mixture ratio is probably out too, can anyone think of a reason why plugs 1 and 2 are sooty and 3 and 4 are wet/black when the engine seems to be running fine. Also, a knowledge question...were some HS4 carbs built without a piston lifting pin? Mine doesn't have one!

Thanks for you help!

Martin

p.s. Normaly my posts aren't this long!

[miniman207]

sooty normally means carbon fouling, fault:- ver ich fuel mixture check:- carb mixture settings, float level, choke operation and air filter.

Wet black plugs means oil fouling Fault:- worn bores/piston rings or valve guides, sometimes occurs temporarily when running in periods.

Good old trusty Haynes!!

Dont know about the HS4 carb sorry

Gaz

[mpett]

Thats what I read too, but is it possible to have two different plug conditions at the same time. (I'm assuming that the bore have al worn evenly!) Is it right to assume this?

[minidaves]

weaken the fuel mixture and u will proberly find the ring seal and valve seal on 1&2 is better

dave

[mpett]

A friend of mine said it could be the valve clearances are set differnetly for 1,2 and 3,4. Any thoughts?

[kada1980]

Hello there fellow westyer

Karl

[Jammy]

Could be valve clearances as mpett has said. I think cylidners 1 and 2 always run slightly richer than 3 and 4 anyway though?

[Hagar]

Are the wet plugs oily or could it be petrol?

I think you might be running too rich and the wet plugs are too wet/fouled to fire properly. I've had this happen when I was mucking around with different carbs.

Check that the jet is seated properly and that the choke is not operating when it shouldn't be. Also check the the carb needle is correclly seated and that the dashpot oil and return spring are present and correct. It wouldn't hurt to check the float level and needle and seat while you're at it.

I'd be inclined to try a new set of plugs, but only for a few minutes after you've done all this, and then see if there's any difference.

As for the lack of a lifting pin, I've seen reference to it on websites, but have never seen a HS carb without one. It hasn't just fallen out?

[mpett]

The carb is a HS4 and the hole where the lifting pin should be is blocked. The spark plugs have been removed, cleaned and moved around. I was performing a mixture setting with a colour tune. I managed to get 3 plugs to be black and sooty and one remained wet. This was always the no. 3 cylinder. I can only assume that the valve clearnaces are messed up. (i thought i'd set the right but obviously not!) I will try and colour tune them again with the valves corrected and let you know.

[chrisls]

Did you ever figure out what the problem was as I am having similar problems with the 3rd cylinder being oily when the others are fine.


Chris.