wear of carbs

Rob · Post by **Rob** » Thu Feb 05, 2009 5:06 pm

How do you know if the Strombergs are worn or not? my landie failed the emissions test!!! it was putting out 10% Co content rather than under 4.5%!!!!! Its a new engine and I tuned it using the colortune beforehand!!!! had one of the Stromberg to pieces.....should the needle wobble side to side???? there isn't no carbon or muck on the needles at all. I'm having difficulty adjusting the mixure.....one carb to seems to do better than the other....but i'm not convinced........can you help please? my carburettors are Strombergs built for the European detox spec.

Larosto · Post by **Larosto** » Thu Feb 05, 2009 8:14 pm

Hi Rob,

`see you`ve got a difficult problem. If the carb is worn, you can see it for example at the jets. The jets are not stil round when they are worn, you can see it when you look acurate. This means mostly, that the needles are worn out too. A worn needle can not always be recognized. A rather clear sign of a worn carb (Stromberg) is that you are not able to make the mixture lean, because the opening between needle and jet is responsible for the mixture.
If needle and jet are worn, (needle becomes thinner, jet becomes bigger), you aren`t able to make the opening between needle and jet small enough at any time, and then your mixture is to rich and you can`t correct it.
If this happens, you have to overhaul the carbs.
Sometimes, the CO is getting better, if you dismantle the tubes from the flame traps during the test, because the engine gets more Oxygene, and this makes the mixture leaner.

I hope this helps, and wish you the best

Horst

map1275 · Post by **map1275** » Thu Feb 05, 2009 11:43 pm

Actually 10% doesn't sound too bad. I assume you have checked Rover specs as opposed to looking at a generic reading. My car is 6% + or - 1%.

Erratic/high idle and possibly running lean: throttle shaft wear can be assessed by physically trying to rock the shafts from outside. The Solex has stem seal to compensate but these have probably perished.

Idle steady, correct and rich: for the age of the vehicle, jet and needle wear can well be the issue (as pre previous post). Car needs to be truly at op-temp of course and fuel type and ignition can affect the reading.

map1275 · Post by **map1275** » Thu Feb 05, 2009 11:46 pm

The needle is spring loaded to allow for easy centring in the jet. Downside of this is that it wears the jet and needle out quicker than a fixed needle. Chronic problem with SU's from 1970's onwards.

Rob · Post by **Rob** » Fri Feb 06, 2009 4:42 pm

I think the timing is set to 6 BTdC and the V8 idle is pretty smooth. The spark plugs are black and sooty, no ajustment will change the colour. its supposed to be a tan/beige colour which is correct mixture. The Land Rover was built in 1982, does age have any bearing on the carbs? its onlt done 82,000 miles. The carbs are original with the restrictor plates still in on a new V8 not run in. Does this have any bearing on on lack of mixture adjustment? The throttle stops are a bit chewed up (not me i hasten to add) where can i get some new ones. They are the tamper proof type screws. I would rather have the the spring/screw set up. The mixture content has to be under 4.5% for MOT. it passed on the other part of emissions test which is the Hydrocarbons.

map1275 · Post by **map1275** » Fri Feb 06, 2009 9:59 pm

Do you have a copy of the actual specs? Otherwise download a copy of the manual from this site. Timing will effect the emissions. My car is somewhere around TDC at 'X' rpm with vac disconnected.

Are you looking at a generic test reading, or the one specified for your model?

If the engine hasn't run in this may effect the readout.

Cut the plastic sleeve off and this should give you access to remove the idle screws and locknuts. They are the same thread as earlier units so they can be replaced by cheese heads and springs.

map1275 · Post by **map1275** » Fri Feb 06, 2009 10:04 pm

After 120 000 KM and 25 years I'd be expecting to pull the carbs apart. If this was an SU I would certainly be expecting new jet and needle if I had to get it to run precisely.

Rob · Post by **Rob** » Thu Feb 12, 2009 4:51 pm

where could i get some new throttle stop screws from? mine are all mangled up (nothing to do with me!!)

disco2hse · Post by **disco2hse** » Thu Feb 12, 2009 8:49 pm

I got my carbs rebuilt after 24 years and 220000 ks. Removed the restrictors and had them properly tuned. Extremely good value for money and fuel economy is just great. Just about time for the annual tune up

map1275 · Post by **map1275** » Thu Feb 12, 2009 11:44 pm

If you get really stuck, try Burlen Fuel Systems. Otherwise any Land-Rover parts supplier. Just explain that you want the screws and springs from an earlier Solex CD. ie a 6 cylinder Land-Rover. If they are smart enough to open the book and look at the pictures, they should be able to work this out. Though this can be asking an awful lot.

sebking · Post by **sebking** » Fri Feb 13, 2009 8:07 am

Burlen first
Gower and Lee second

Rob · Post by **Rob** » Fri Feb 13, 2009 5:01 pm

I want to keep the vehicle original if i can. but if all else fails, would putting a pair of SU's a good bet on the V8? I know these don't have a rubber diaphragm like the Strombergs.

disco2hse · Post by **disco2hse** » Fri Feb 13, 2009 8:16 pm

For normal road running, they're fine. If you are going into rough or steep territory then you may have problems with fuel spilling out of the float chamber. Quite a few people around here used to replace the Strombergs with SU's because they thought the SU were better. Since then other better options have emerged (like LPG) and so the perceived improvement gained from putting in SU's is not as great as it was. Once they are tuned the Strombergs seem fine and I really don't think there is any less maintenance involved if you go with SU's.