Thread: Why??

The principle is the same for all CD carbies and its a good site if you have early carbies.... however anything from 80 onwards the carbies while they looked the same used very different methods to adjust the mixture


Cheers

Baggy

Originally Posted by Baggy

The principle is the same for all CD carbies and its a good site if you have early carbies.... however anything from 80 onwards the carbies while they looked the same used very different methods to adjust the mixture


Cheers

Baggy

Bugger! Does anyone have the documentation

20degrees rather than 40degrees today and it's back to it's old self. The first 1/4cm of throttle movement (after the slop is taken up in the cable) doesn't do much and feels like the engine is leaning out... hmmmmm

seeya,
Shane L.

Shane,

Identification of type of CD carbie is a bit hit and miss as I don't believe there is any phyical identification on the actual carbies themselves.
Year of vehicle is normally the best way, but no guarentee if you dont know if its the original engine.

Supposedly they came with an identification tag that was held by one of the cover screws ....but you can guess how long they would stay there.

You can identify carbie by looking underneath at the carbie bowls and early ones have brass fitting with adjustment as per your link you supplied.
Later carbies don't have the brass fitting, and need special adjusting tool for mixture.

That will be your starting point ........

There are two special adjusting tools (for later models) one with hex head, I believe and a seperate one (recessed slot) they brought out for the 81 3.5 v8 which I have.

Cheers,

Baggy

Originally Posted by Baggy

Shane,

Identification of type of CD carbie is a bit hit and miss as I don't believe there is any phyical identification on the actual carbies themselves.
Year of vehicle is normally the best way, but no guarentee if you dont know if its the original engine.

Supposedly they came with an identification tag that was held by one of the cover screws ....but you can guess how long they would stay there.

You can identify carbie by looking underneath at the carbie bowls and early ones have brass fitting with adjustment as per your link you supplied.
Later carbies don't have the brass fitting, and need special adjusting tool for mixture.

That will be your starting point ........

There are two special adjusting tools (for later models) one with hex head, I believe and a seperate one (recessed slot) they brought out for the 81 3.5 v8 which I have.

Cheers,

Baggy

Ok, that makes sense. From memory these carbs are Zenith CD175's. They are certainly '85 models. I can soon turn up any special tool required so it's not a big issue.

I seem to recall seeing those tools on a web page a while back when I was looking for carby kits. I can't find any evidence of vacuum leaks anywhere, so I'm assuming they setup these carbs to run really lean to try and meet the pollution standards without injection.

EDIT: Bugger I was wrong, these ones are Solex:

http://www.aulro.com/afvb/technical-...x-carbies.html

How good is my memory ( talk about a 5second memory) I'd linked the page that describes how to adjust the mixtures previously .............

seeya,
Shane L.

Be prepared to find that your 175CDs are running rich on the needle jet for the following reason: the needle (as observed on my 1981 RRC) is held in the slide by a spring-box device. Where the spring bears on the needle, there is a tag, but ONLY ON ONE SIDE. Thus the spring pressure causes the needle to tilt and rub on one side of the jet as it slides up and down. This will eventually cause wear to the jet orifice (and probably also the needle), and results in a richer mixture.
I have a motorcycle that never ran right from when I bought it, despite changing slides, main jets, idle jets, needles, etc. Finally I changed the needle jets and the problem was solved. The problem with the 175CDs is that the needle jets are pressed in and do not appear to be replaceable.

Originally Posted by Phil HH

Be prepared to find that your 175CDs are running rich on the needle jet for the following reason: the needle (as observed on my 1981 RRC) is held in the slide by a spring-box device. Where the spring bears on the needle, there is a tag, but ONLY ON ONE SIDE. Thus the spring pressure causes the needle to tilt and rub on one side of the jet as it slides up and down. This will eventually cause wear to the jet orifice (and probably also the needle), and results in a richer mixture.
I have a motorcycle that never ran right from when I bought it, despite changing slides, main jets, idle jets, needles, etc. Finally I changed the needle jets and the problem was solved. The problem with the 175CDs is that the needle jets are pressed in and do not appear to be replaceable.

I'll try to have a look next weekend. This one definitely feel like it's running lean though. Would a tiny hole in one of the diaphrams cause this maybe ?

I'm not keen on pulling the carbies off until I have kits ready to put through them

seeya
Shane L.

I've spent the last few nights trying to tidy up the shed and hunt down all the missing tools. I grabbed these off the floor of the Rangie along with some of the missing tools......... Notice anything

This car was used as a "paddock ute" for the last 10years, so the black plugs IMO are normal. ie: it should have done a lot of cold running with choke out. There not oily (phew) just black. the other 4 are wwwaaaayyy lean... no carby motor should have such white plugs. I obviously have one carby that's running very lean. It would have made it easy if I'd taken notice and checked which carby fed the cylinders with the clean plugs



woops, the piccie didn't load. It shows 4 black plugs, and 4 very white plugs.

The solex carbies are a bugger to find any information or kits for. I've emailed the guy selling these kits:

Stromberg CD175 Carb Overhaul KIT Suit Range Rover Triumph Holden Volvo | eBay

He reckons they'll be ok, it's a "universal" type carby kit, so there will be bits and I won't need and bits I will. Sounds good to me

seeya,
Shane L.

I just lifted the carby pistons up as described in the attached article... and it stumbles and dies equally both sides I was sure one carby would be noticably lean..... Oh well, the steering pump side carby is filthy with fuel staining ... and the other is quite clean ... I start to pull it off ... get this ... Only one carby has a choke Does that mean half the motor runs lean as buggery and half it rich if you pull the choke out. No wonder it an b@stard of a thing when cold That explains 4 clean plugs and 4 black ones too.

I swear it's tried to kill me a couple of times pulling into the intersection at the end of my street. You pull into the intersection and put your foot down, and it'll die completelly ...... lean out instantly to the point where your completely stranded in the middle of the intersection with cars bearing down on you ...... So you frantically pull the choke out as far as it'll go..... slam the clutch in and give it and give it a good huge rev and ride the **** out of the clutch to try and get it off the road and out of the intersection .

Oh well I'll post some piccies of the dismantled carby and see what's the go.

seeya
Shane L.