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Andy
Ready for SVA
Joined: Thu Nov 15, 2007 10:22 pm Posts: 363 Location: Ireland
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45 Weber carbs
Does anyone on here know much about 45 Weber carbs, before I stripped the car for painting I found the engine was very hard to start and seemed to flood itself (wet plugs), I use to (back in the racing days) give one full pump of the accelerator before starting and she would normally fire, but this engine seems to take ages to start. Any clues or suggestions on what to look at. I tried backing off the fuel pressure, turning off the fuel pump, not pumping the accelerator but nothing seems to work. It's worse when it's cold but even once warm it still stuggles.
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Wed Jan 06, 2010 10:53 pm |
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Mr Mac
Ready for SVA
Joined: Thu Dec 24, 2009 9:31 pm Posts: 274 Location: NW Leicestershire GTM: Cox/Coupe
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Re: 45 Weber carbs
Have you checked the float level?
David
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Wed Jan 06, 2010 11:40 pm |
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Andy
Ready for SVA
Joined: Thu Nov 15, 2007 10:22 pm Posts: 363 Location: Ireland
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Re: 45 Weber carbs
It's one thing I know nothing about (carbs), how do I do that and what am I looking for
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Thu Jan 07, 2010 9:43 am |
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Mr Mac
Ready for SVA
Joined: Thu Dec 24, 2009 9:31 pm Posts: 274 Location: NW Leicestershire GTM: Cox/Coupe
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Re: 45 Weber carbs
Andy
The float level controls the amount of fuel in the carb - it's a bit like the float valve in your toilet. If it is set too high then you will have an overflow problem. You need to take the top of the carb and then set it at a certain dimension. This then stops fuel being pumped in to the reservoir inside the carb.
Before you start taking the carb apart you need to get a service kit which will include the gasket that seals the top and bottom half. I have a book in my workshop which I shall dig out this evening.
David
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Thu Jan 07, 2010 12:59 pm |
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turbocox
Where is my Number Plate?
Joined: Mon Oct 01, 2007 7:25 pm Posts: 974 Location: Near Milton Keynes GTM: Cox/Coupe
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Re: 45 Weber carbs
I have Limited knowledge of these(45's), and struggled for ages Almost reducing me almost to tears (sad times). I feel your pain chap. The only advice I can offer is to seek the advice of Southern carb's or your local Rolling road, I know it costs but I'm sure it will help find the cause of the problem.
_________________ THE WORLD'S FASTEST 'A' SERIES COX GTM Standing 1/4 Mile in....13.502 @115mph MITP 08
Last edited by turbocox on Thu Jan 07, 2010 7:55 pm, edited 1 time in total.
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Thu Jan 07, 2010 1:38 pm |
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Mr Mac
Ready for SVA
Joined: Thu Dec 24, 2009 9:31 pm Posts: 274 Location: NW Leicestershire GTM: Cox/Coupe
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Re: 45 Weber carbs
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Thu Jan 07, 2010 1:50 pm |
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Mr Mac
Ready for SVA
Joined: Thu Dec 24, 2009 9:31 pm Posts: 274 Location: NW Leicestershire GTM: Cox/Coupe
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Re: 45 Weber carbs
Another suggestion before you start pull your carb apart would be to do a plug/lead/cap/arm/coil/points change. If you have a weak spark this would also result in the engine cranking and wet plugs.......
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Thu Jan 07, 2010 1:59 pm |
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the other Tim
The Terrible Tims
Joined: Sat Sep 29, 2007 12:23 pm Posts: 487 Location: suffolk GTM: Cox/Coupe
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Re: 45 Weber carbs
Andy, if your battery is in the front then it may be worth checking for voltage drop, also what loom are you using?
_________________ I'm not a complete idiot, parts of me are missing!!!!!
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Sat Jan 09, 2010 12:48 pm |
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Andy
Ready for SVA
Joined: Thu Nov 15, 2007 10:22 pm Posts: 363 Location: Ireland
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Re: 45 Weber carbs
Mr Mac wrote: Another suggestion before you start pull your carb apart would be to do a plug/lead/cap/arm/coil/points change. If you have a weak spark this would also result in the engine cranking and wet plugs....... Mr Mac Thanks for you help I have new plugs, new leads, new cap, new arm, new coil, no points its an Aldon Red/Yellow non vac dizzy with electronic ignition the other Tim wrote: Andy, if your battery is in the front then it may be worth checking for voltage drop, also what loom are you using? Tim Yep battery in front, was thinking that it may be voltage drop earlier on, I changed the starter cable to a serious cable (can't remember what gauge but it significant) to help reduce drop here (initial thoughts were a lazy starter), I may have a similar problem with the coil loom cable, as for loom its the one that was in the car modifided for some additional fixtures, I will be updating this with my own one on rebuilding, I have a feeling it maybe a combination of a number of problems, older carb not used for a while (I have had it serviced but only I minor service), incorrect float level, lazy starter motor and possibly voltage drop at the coil duing start up.
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Sat Jan 09, 2010 7:29 pm |
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West
Admin, and Coupe Nutter
Joined: Fri Sep 14, 2007 10:34 pm Posts: 1762 Location: In the workshop GTM: Cox/Coupe
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Re: 45 Weber carbs
Andy wrote: older carb not used for a while If it has been sitting with old fuel in it or that has evaporated may have left some sledge behind have seen this clog up a Holley before now causing bad running and difficulty to start. so might be worth a clean out too. West
_________________ IF wile e coyote had a GTM he would have one with Nitrous too! watch out road runner! The First GTM into the 11s then the 10s, PB 10.87 @ 125.5 Mph on A048 tyres, and fully road legal at Santa Pod
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Sat Jan 09, 2010 9:57 pm |
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the other Tim
The Terrible Tims
Joined: Sat Sep 29, 2007 12:23 pm Posts: 487 Location: suffolk GTM: Cox/Coupe
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Re: 45 Weber carbs
Andy to check the coil supply voltage put a decent multimeter from the sw/+ (could be marked with either one)terminal to earth as you (or the missus ) are cranking the engine. Like you the Weber/Dellorto equipped cars i've had in the past have always started with a couple of pumps and opening the throttle a whisker during cranking, i've never connected the choke cable up Are you getting a couple of decent squirts of juice as you open the throttle, easily seen as you look down the chokes It should fire on this even it does'nt catch.
_________________ I'm not a complete idiot, parts of me are missing!!!!!
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Sat Jan 09, 2010 10:10 pm |
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Andy
Ready for SVA
Joined: Thu Nov 15, 2007 10:22 pm Posts: 363 Location: Ireland
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Re: 45 Weber carbs
the other Tim wrote: Andy to check the coil supply voltage put a decent multimeter from the sw/+ (could be marked with either one)terminal to earth as you (or the missus ) are cranking the engine. Like you the Weber/Dellorto equipped cars i've had in the past have always started with a couple of pumps and opening the throttle a whisker during cranking, i've never connected the choke cable up Are you getting a couple of decent squirts of juice as you open the throttle, easily seen as you look down the chokes It should fire on this even it does'nt catch. Tim, I will check the voltage when its all connected back up, yeah I was surprised with the amount of time it took to fire, I will check it all when I put it back together, I was just looking for some dvise in the mean time, thanks for all your comments.
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Sat Jan 09, 2010 10:26 pm |
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RaymondH
On the Road
Joined: Tue Jun 17, 2008 9:11 pm Posts: 604
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Re: 45 Weber carbs
It's not really a big deal to take the top off the carb and have a look inside it - it's much easier than it looks and I've done it loads of times without having to replace a gasket. Also, with it having a shared float chamber you can remove the jets etc one at a time to check that they're clean and still have another set on the other side to check how they go back if you need to. When I stripped my HIF44 SU down it had sat for ages and the amount of corrosion inside it was unbelievable but it all cleaned off easily enough. If you need a manual Haynes do a good one with all the usual exploded diagrams.
_________________ Education is important. Cars are importanter.
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Sun Jan 10, 2010 8:07 pm |
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Mr Mac
Ready for SVA
Joined: Thu Dec 24, 2009 9:31 pm Posts: 274 Location: NW Leicestershire GTM: Cox/Coupe
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Re: 45 Weber carbs
Andy
Do you still need me to scan the manual?
David
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Tue Jan 12, 2010 10:16 pm |
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Andy
Ready for SVA
Joined: Thu Nov 15, 2007 10:22 pm Posts: 363 Location: Ireland
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Re: 45 Weber carbs
David,
No I actually went out a brought a full copy, but thanks anyway
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Wed Jan 13, 2010 9:21 am |
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