MOT

[olliebarrett_92]

Well, I have just got back from the Garage where my Stage One had its first MOT, in a few years. And before you ask, yes it did fail, but to be honest I was expecting it to! haha

Surprisingly it didnt actually fail on that much, the hydro-carbon emissions were way to high, which I have been told is due to the carburettors. The bloke at the gargage had a fiddle around with them but what ever he did couldnt get the reading low enough. At the moment I have got Zenith carbs on it, and he recommended that I put Webbers on. Does anyone have any info, as to whether its wise or not. And has anyone done this before, if so was it a wise improvement.

The other things that it failed on were:
- A bit of rotten chassis, needs welding.
- The nearside front brake is binding
- Nearside front CV joint is excessively worn

If anyone has got any recommendations or any advice for me as to how I so go about getting it ready for a re-test, I would be very greatful!
Thanks alot,
Ollie

[sebking]

I'd clean the carbs first and check they are set up properly and diaphrams are good.

I'm running SUs which I prefer and understand better than zeniths.

Then check the dwell and timing - actually check this first and then the carbs.

How high was the HC.

I'd look for the easy before going down the weber route as these are a pig in my experience!

[glencoyne]

Stromberg (Zenith) carbs can be a bit fiddly to set up, but I have never had a high HC problem with them. Usually it is the CO reading that is difficult to get down to MOT level. The one problem the Strombergs suffer from quite frequently is that the rubber diaphragm under the dashpot cover splits. Undo the four screws holding the cover on, carefully remove it and then you can lift out the piston and diaphragm. Inspect the diaphragm carefully for splits or perishing - or else just replace it anyway, as they aren't expensive.

High HC readings can be caused by incomplete combustion due to ignition problems, so go through the ignition system carefully and make sure everything is set up 'by the book'. In particular, if you have been playing about with the system before, make sure you haven't got two plug leads swapped over - the engine will run better than you would think on 6 cylinders, but the HC readings will be terrible.

If you have everything set up perfectly and still can't get the HC reading down, it might be time to start worrying about other problems such as camshaft wear (especially if the engine seems a bit down on power and spits back through the carbs under load).

[sebking]

I've just finished outside for the day and carbs are next.

I'm certain it is running rich as my eyes are watering! Will stick the CO meter on it.