solex's

For you flat four Porsche 912 fanatics

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hunter
Married to the DDK
Posts: 235
Joined: Sat Oct 01, 2005 4:09 pm
Location: West Yorks

solex's

Post by hunter »

As you may remember i decided to get my carbs rebuilt by carburettor exchange and thought i might tell you where we are with it.

When i first got the carbs back from them after 6-7 weeks i was really quite shocked at the state they came back in.

On inspection I found the bores full of swarf from machining :shock:

There was also swarf /machining build up in the small holes within the bores of the carbs and the whole job looked very unfinished.

This led me to inspect them more closely.


I have detailed below the main problems I found with each unit – of particular concern was a huge burr of alloy that was attached inside the bore of the right unit.


Right Unit


Front Throat

Scoring around throttle shaft bushing

Burrs in carb body where it meets the venturi

(there is a huge burr in here that came away when I was inspecting the carbs)



Rear Throat

Deep spiraling score mark running around venturi from the bottom to approx halfway up. (the result, i was told, of drifting them out)


General

Butterflies jam in body when at rest with no idle dialed in.

They also do not close off fully

Butterflies have score marks on them.

Accelerator pump arm twists in housing before operating the pump



Left Unit


Front Throat

Burrs in carb body where it meets the venturi


Rear Throat

Scoring around throttle shaft bushing


General

Butterflies have score marks on them.

Carb top not cleaned with rest of carb

Jets were loose.

On further inspection I found that the accelerator pump settings were incorrect.

When I tried to correct this I found one of the nozzles did not spray directly downwards but fanned out. (something in the nozzle?)

I also noticed then that the nozzles weren't positioned correctly to spray down the bore and that the heights of 2 of the nozzles were different.
I am led to believe these heights are important?

Original arm springs were replaced with non original
Different mixture screws fitted – the original type are much longer and sharper.

I sent them back to carb ex after a phone call.

and got them back a few days later with the problems mostly sorted. The guy said he was a bit annoyed at my letter detailing the problems :shock: - He was annoyed!? :evil:

Anyway that was about a month ago - and over the last week or so i have been getting them back on and trying to set them up.

This was much harder than it should have been as i subsequently found out the condensor on the dizzy was duff. :roll:

Took a bit of working out and only just sorted that tonight. I have now fitted the pertronix unit which has got the car sounding, starting and driving much better - but there is still a small problem.

The problem is the idle mixture.
Due to the fact that carb ex replaced my screws with the much shorter blunter type i can't get the mixture right.

When i first set them up at 1 1/2 turns out the car sounded like a tractor.
Far too much fuel was going in. Not having really done this before i didn;t have a clue what was happening or why. Then realized that the shorter screws were letting in too much fuel at 1 1/2 turns

Set them at 1/2 turn out and your in the ball park. but trying to get that final adjustment is harder than it should be and its either too rich or too weak -

The car is now running much better though and pulls like a train but my last outing was running a little too weak and she nearly died once or twice.

I'm sure i could dial these in with a bit of patience but it just doesn't seem right having the screws that far in and the springs compressed so much.

I am certain that once i can get hold of the correct screws i can sort this.

Can anybody tell me where i can get these from (they are the longer type with the large plastic heads)

Or if anybody has any they would like to sell me i would much appreciate it as i'm dying to get out and get her sorted while i can -
we have a baby due in about 4 weeks and i'm guessing i wont have too much time to myself. What little time i do have i would rather spend driving - not fixing

Cheers for now
Darran

Bahama Yellow 67 912 - sold
912uk
Nurse, I think I need some assistance
Posts: 5954
Joined: Wed Nov 12, 2003 11:02 pm

Post by 912uk »

give me a call 01489 602936 later tonight I need to call him back my self and I had this very chat with Andy Prill that there have been some bad work coming out he showed me a set he has had done and they looked and were perfect. i need to get pictures togeather and confront him as it was me that recommended them to every one and I am not happy and not happy to continue to find people not happy. I found Carb exchange out the back of Practical Classics I called them and they sounded very much like they knew what they were doing and I then spoke with Andy some years back and when i said I had the carbs done right he expressed his usual concern about who did them.. when I said who i used he said they were good and he had taught them a trick or two on the rebuilding of them, So I thought for once I had done some thing right..

Call me I need to get mine sorted and yours and any one else that has had problems I may ask Gavin if it is a good idea to keep posting up their name when it comes to carbs.

but can you post pictures of these carbs and the workman ship
davidppp
DDK rules my life!
Posts: 1064
Joined: Sat Jan 08, 2005 9:51 pm

Post by davidppp »

Hello Darren.

So sorry to hear this sad tale..
I guess you have been able to set the flaot levels right?

This is often not done with the Solexes..

If they chnaged the needle valves they may not be sealing consistently..is the pump set up the OEM or have you changed it?

they do not like much pressure..

No help to you now, but the ones I have on my -12, done by Eurometrix are perfect..better than new for sure..I have heard bad things about all the UK carb so-called specialists over the years..not just with Porsches..

Kind regards
David
hunter
Married to the DDK
Posts: 235
Joined: Sat Oct 01, 2005 4:09 pm
Location: West Yorks

Post by hunter »

Mark i do have some pictures - but i dont know how clear they will be - i will check on them later and give you a bell.

David - checked the float height with the p78 tool (which incidentally was a cheap piece of crap that leaked like a sieve and then cracked when i tried to tighten it up - good old mark at Brays has been onto stoddards for me and has a new one on its way as we speak)

I set the injection qtys using the correct vial (.45cc for 2 strokes)

These were pumping out way too much when i first got them back from carbex - no way they had been set up.

I have spoke to dave at carbex this morning to see if he still has my screws - and he hasn't.

He said the screws he fitted were measured against mine and were found to be near enough the same - bollocks

When i first looked at rebuilding my carbs i got a rebuild kit from brays and the screws in the kit were nothing like mine - much shorter and blunter - these are the same screws carb ex have fitted.

Carb ex said that fitting a smaller idle jet would help - which he sells at about £4 each

Its odd but i get the feeling that carb ex didn't even do my carbs as he told me they had been bench tested and run fine - then i receive them back full of swarf and crap? Theres no way they could have run ok
Darran

Bahama Yellow 67 912 - sold
912uk
Nurse, I think I need some assistance
Posts: 5954
Joined: Wed Nov 12, 2003 11:02 pm

Post by 912uk »

hmmm I also got the feeling he may have subbed out some of the work as Andy was ready to fight his case about the good work and that he would stake his claim that he would never have used SILICONE !! on the carbs when rebuilding them..

So the result is I have STACKS of F**** silicone in the carbs so either

I am a lyer ( which I know I am not and have NOT touched them only the one time I was stuck on the side of the road with blocked jets of silicone !!!! )

Or he had some one else build them, on the back of his reputation.. and taking short cuts and doing things wrong!!

Which is now what I suspect!!

My Question is how does Andy get the carbs back perfect and we get the problem ones..

Any way what I can say is the carbs are not set up in any way once we get them back I knew this when they arrived they may have been bench tested but I can assure you it's just to see the float levels work and the accelerator jets work and the idel jets after that it's up to use to set them up..

but what I don't get it the

Sticking butterfly's
Leaking jets
and what look to be wrong jets fitted ( I would need to look into this more )
Gilbert '71 T
I luv DDK!
Posts: 894
Joined: Sun Oct 03, 2004 9:12 am
Location: N London

Post by Gilbert '71 T »

Bloody hell Darran, really sorry to hear about this, it's an outrage considering the price and the turnaround from these guys :evil:

the kit i threw at mine seems to have got me by, however I was considering sending them off to carb-ex come the winter.....I'll think once about that now :roll:

Hope you get things sorted out soon.
Darren
71 911T with C3 motor
hunter
Married to the DDK
Posts: 235
Joined: Sat Oct 01, 2005 4:09 pm
Location: West Yorks

Post by hunter »

Hi Darren

Yeah just a bit cheesed off really.

Its sort of getting there now - i've fitted some smaller idle jets but the mixture screws are a bit of an all or nothing affair.

I've found the correct screws at stoddards but they have just qouted me $91 dollars for 4 screws and springs!!!!

They have got to be taking the p155

I've mailed them to ask for a breakdown on costs - will be interesting to see how much they are charging for shipping.


Darran
Darran

Bahama Yellow 67 912 - sold
Del
DDK forever
Posts: 594
Joined: Wed Aug 08, 2007 8:58 am
Location: Leicester

Post by Del »

I havent read every word of this thread, but if it helps, and im not sure it will... there is a great place here in Leicester who are reputedly absolutely one of the best places around for tuning and setting up twin solex's. If you want any info about the place i can find out more and let you know. They are not a flash garage that advertises all over the place, just good old fashioned mechanics with a deep and indepth knowledge of what they are doing.
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