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Coughing and spitting on tripples
- Thread starter vipergts
- Start date
SeanDezart
Well-Known Forum User
The line ? 63mm.
I've got 36 chokes on a 2.4 and it pulls through rev range fine. I previously had 38s and it had a big flat spot where as you say there wasnt enough air speed to get onto main jet. But it was always a clean flat spot 
no spitting.
So i don't think your problem is the 36s.
If the linkages are reasonably synchronised, my guess would be that a some of the accelerator jets are blocked.
To check: if you look down each choke while you open the throttle you should be able to see a stream of fuel while the throttle is moving.
no spitting.So i don't think your problem is the 36s.
If the linkages are reasonably synchronised, my guess would be that a some of the accelerator jets are blocked.
To check: if you look down each choke while you open the throttle you should be able to see a stream of fuel while the throttle is moving.
I've got 36 chokes on a 2.4 and it pulls through rev range fine. I previously had 38s and it had a big flat spot where as you say there wasnt enough air speed to get onto main jet. But it was always a clean flat spot
So i don't think your problem is the 36s.
If the linkages are reasonably synchronised, my guess would be that a some of the accelerator jets are blocked.
To check: if you look down each choke while you open the throttle you should be able to see a stream of fuel while the throttle is moving.
Thats interesting.......Thanks
If I can chime in, you should check the jets and report your findings.
We are many with DCOE in Europe but also in the US. So we should have a good baseline to compare your setup with others. If you're in the ballpark, we can assume issue is coming from elsewhere.
DCOE's need to be setup properly but your issue is major, you have something really out of tune if it is in the carbs, we should be able to spot discrepancies just by looking at your setup.
You did not tell us which kind of 45DCOE you've got, the 152's are newer and might need some special adjustments.
I'm more involved with 40DCOE (my setup), I know that 40DCOE 18 are easier to setup than newer 151 serie that requires drilling new progression holes to work fine with our L engine, for instance. That may applicable to your 45DCOE.
I would also check everything you could by yourself on those carbs: float level, needle valve, floats, synch between barrels, filters shape (dirty?), air leaks, etc...
For synchronisation, despite speeches, I have excellent results with a fuel hose in my hear on one side and the other side in the air horn to listen to the flow.
Same technic could be used to spot air leaks, you can clearly hear them by checking them with the end of the hose.
Last advice, you should check your idle screw to see how many turns you need to close them and see how they are setup. Make sure to count how many 1/4 of turns you'll need (without force otherwise you'll damage your idle screws) to get back to where you are now. you should be around 1 to 1.5 turns on every barrel, if you're not, something is wrong.
We are many with DCOE in Europe but also in the US. So we should have a good baseline to compare your setup with others. If you're in the ballpark, we can assume issue is coming from elsewhere.
DCOE's need to be setup properly but your issue is major, you have something really out of tune if it is in the carbs, we should be able to spot discrepancies just by looking at your setup.
You did not tell us which kind of 45DCOE you've got, the 152's are newer and might need some special adjustments.
I'm more involved with 40DCOE (my setup), I know that 40DCOE 18 are easier to setup than newer 151 serie that requires drilling new progression holes to work fine with our L engine, for instance. That may applicable to your 45DCOE.
I would also check everything you could by yourself on those carbs: float level, needle valve, floats, synch between barrels, filters shape (dirty?), air leaks, etc...
For synchronisation, despite speeches, I have excellent results with a fuel hose in my hear on one side and the other side in the air horn to listen to the flow.
Same technic could be used to spot air leaks, you can clearly hear them by checking them with the end of the hose.
Last advice, you should check your idle screw to see how many turns you need to close them and see how they are setup. Make sure to count how many 1/4 of turns you'll need (without force otherwise you'll damage your idle screws) to get back to where you are now. you should be around 1 to 1.5 turns on every barrel, if you're not, something is wrong.
rallymanDP
Well-Known Forum User
When you buy a set of new Webers nowadays they supply them with just the chokes & jets that the Factory fits - i.e you cannot specify the best ones for the Engine, even though several Owners on here know ( approximately ) the correct ones that past experience has taught them.
You have to buy all new ones at another £120+ and throw the others away - a complete rip-off.......a bit difficult to tell Customers the situation but I suspect that is what happened to ViperGTS.
Good posting above by Lazeum - very accurate & constructive.
You have to buy all new ones at another £120+ and throw the others away - a complete rip-off.......a bit difficult to tell Customers the situation but I suspect that is what happened to ViperGTS.
Good posting above by Lazeum - very accurate & constructive.
Thanks for the info.
I'm not sure but the I'm fairly sure the guy who was attempting to set them up said they were the old styleeee.
He set the idle and also messed with mixtures etc but concluded the chokes were too large (I wasn't convinced)
I bought some 34's and 32's and fitted the 34's and there is no difference.
Bonnet open with me controlling the revs at around 1500-2000 rpm and watching the each and every choke spit back randomly.
Since this was never that bad I'm pretty sure its not set up and I've blown jets out etc.
So I reckon its not the carbs and that it could be the dizzy. I've had problems with this before.
The mesh filters are a little more than what they appear....the filter is finer than it looks but would agree its not sufficient but its a darn sight easier to play with for them moment and its not a high miler in constant use.
I'm not sure but the I'm fairly sure the guy who was attempting to set them up said they were the old styleeee.
He set the idle and also messed with mixtures etc but concluded the chokes were too large (I wasn't convinced)
I bought some 34's and 32's and fitted the 34's and there is no difference.
Bonnet open with me controlling the revs at around 1500-2000 rpm and watching the each and every choke spit back randomly.
Since this was never that bad I'm pretty sure its not set up and I've blown jets out etc.
So I reckon its not the carbs and that it could be the dizzy. I've had problems with this before.
The mesh filters are a little more than what they appear....the filter is finer than it looks but would agree its not sufficient but its a darn sight easier to play with for them moment and its not a high miler in constant use.
To know your carb type, it isn't a super reliable way of checking but you should have some numbers on your covers after "45DCOE" such as "9", "152", or other number. Another way would be to check how your floats looks like (brass or plastic? if you remove the cover, be very gentle since you might risk to bend stuffs) and progression ports (you should have a brass cap to unscrew). Based on your pictures, it looks like old style with smoother cover style (new ones have a triangular part on covers)
If you have tried to just change the choke from 36mm to 34 without changing jets, it is very likely things will not get better. Chokes are changing how carbs are pulling air so every jets need to be adjusted. The only way it could have improved is if your carb was coming back to being tuned with 34 since they're obviously not with 36mm.
To help you, we need to know the idle jets & other jets you have in your car. Remove the small caps on top of the cover, unscrew the 4 brass "bolts" with a large flat head screw driver and check the numbers printed on each component. Maybe, you could also see the floats by doing so. That would give us the specs of your idle jets, main jets, air jets and emulsion tubes.
It could very be the distributor as well, popping thru carbs is one of the effect of too low advance. What is your setup btw? with DCOE, you need high initial advance (since you don't have vaccum plugged to compensate) & nomal total advance making stock distributor somehow tricky to be used. It seems yours is recurved, so it should be good to go.
One easy test however could be to loosen slightly the distributor before starting the car so you can rotate it by hand but it can still stay in position (put a mark somewhere before to get back to where you are once test is over), start the car, let it sit at idle and turn the distributor gently (no more than 2-3° at a time) and see if rpm go up or down. Optimal timing would be when rpm is at the highest. counter clock wise = more advance. Do this test with hot engine.
By doing so, you'll also change total timing, so driving your car without knowing where is total timing is risky (ping, detonation, heat, etc.) so I don't recommand it and you should get back to where you are now.
If you find out timing is quite ok, it is most likely not a timing related issue.
If you have tried to just change the choke from 36mm to 34 without changing jets, it is very likely things will not get better. Chokes are changing how carbs are pulling air so every jets need to be adjusted. The only way it could have improved is if your carb was coming back to being tuned with 34 since they're obviously not with 36mm.
To help you, we need to know the idle jets & other jets you have in your car. Remove the small caps on top of the cover, unscrew the 4 brass "bolts" with a large flat head screw driver and check the numbers printed on each component. Maybe, you could also see the floats by doing so. That would give us the specs of your idle jets, main jets, air jets and emulsion tubes.
It could very be the distributor as well, popping thru carbs is one of the effect of too low advance. What is your setup btw? with DCOE, you need high initial advance (since you don't have vaccum plugged to compensate) & nomal total advance making stock distributor somehow tricky to be used. It seems yours is recurved, so it should be good to go.
One easy test however could be to loosen slightly the distributor before starting the car so you can rotate it by hand but it can still stay in position (put a mark somewhere before to get back to where you are once test is over), start the car, let it sit at idle and turn the distributor gently (no more than 2-3° at a time) and see if rpm go up or down. Optimal timing would be when rpm is at the highest. counter clock wise = more advance. Do this test with hot engine.
By doing so, you'll also change total timing, so driving your car without knowing where is total timing is risky (ping, detonation, heat, etc.) so I don't recommand it and you should get back to where you are now.
If you find out timing is quite ok, it is most likely not a timing related issue.
Last edited by a moderator:
Start with the absolute basics and avoid myths, hyperbole and assumptions by trying to understand how the “whole” works
I would still like to know more about the engine, in particular the cam, one of the most common mistake on an engine is to over cam it, i.e. excessive/wrong lift, duration, overlap etc for the breathing characteristics of the engine, inappropriate cam profiles make any carb adjustments futile as your just fighting a fundamental problem.
For example a long duration cam with a late closing inlet valve can result in the engine spitting at low rpm, but then again so can ridiculously large ports…
A rapid opening ramp on a lobe can result in fuel drop out due to velocity loss also at low rpms, but then again so can large valves.
Poor cam choice can kill dynamic compression so that your street fighting 11:1 actual is nothing more than a weak fart when it’s running, alternatively it can det like a sod.
Compression, what is it, whoever built the engine should provide you with a build sheet, if they don’t ask for it.
The list goes on.
As previously mentioned you can’t just slap engines together, each component needs to compliment the other and tie up with the basics of capacity/flow and driven primarily by usage.
Final note
Very few people on this or any other car forum have actual achieved any of this let alone understand it.
I would still like to know more about the engine, in particular the cam, one of the most common mistake on an engine is to over cam it, i.e. excessive/wrong lift, duration, overlap etc for the breathing characteristics of the engine, inappropriate cam profiles make any carb adjustments futile as your just fighting a fundamental problem.
For example a long duration cam with a late closing inlet valve can result in the engine spitting at low rpm, but then again so can ridiculously large ports…
A rapid opening ramp on a lobe can result in fuel drop out due to velocity loss also at low rpms, but then again so can large valves.
Poor cam choice can kill dynamic compression so that your street fighting 11:1 actual is nothing more than a weak fart when it’s running, alternatively it can det like a sod.
Compression, what is it, whoever built the engine should provide you with a build sheet, if they don’t ask for it.
The list goes on.
As previously mentioned you can’t just slap engines together, each component needs to compliment the other and tie up with the basics of capacity/flow and driven primarily by usage.
Final note
Very few people on this or any other car forum have actual achieved any of this let alone understand it.
Well the problem has never been so bad moving from a flat spot with an occasional spit to constant spitting and farting so its not an inbuilt problem which is why I'm moving back to the dizzy cos this caused me grief before.
Geoff at Fourways says he has built many of these engines without issues. I'm down there tomorrow to swap over dizzy and will go from there. If it runs better then I'll take it to a rolling road with a very experienced tuner.
However if it doesn't run properly I need to find someone who knows what they're doing and start from scratch maybe pulling the engine apart and re speccing it.
OR SET LIGHT TO THE *******
Geoff at Fourways says he has built many of these engines without issues. I'm down there tomorrow to swap over dizzy and will go from there. If it runs better then I'll take it to a rolling road with a very experienced tuner.
However if it doesn't run properly I need to find someone who knows what they're doing and start from scratch maybe pulling the engine apart and re speccing it.
OR SET LIGHT TO THE *******
SeanDezart
Well-Known Forum User
So ask Geoff which cars, which owners have not had issues. I think most of us have heard of cars originating there that have had issues solved elswhere.
Don't blame it on the car or the carbs.
Don't blame it on the car or the carbs.
Albrecht
Well-Known Forum User
No, you just need to take it to a rolling road.
If they are the modern 'vintage' Spanish made 45DCOE-9s ( judging from the photos ) then I'm willing to bet they are the 'out of the box' settings / jets.
That would give you 36mm chokes, 145 main jets, 155 air correctors, 55F8 idles, 45 pump jets and F16 emulsion tubes. I think they have the 'short' 10mm stroke accelerator pump rod stroke too ( Weber recommended the longer 12mm stroke for the L-series ).
And therefore the setting will be way off what your engine really wants.
Let's be honest here, you would hear all sorts of anecdotes about ALL ( and I mean ALL ) of the so-called 'Z-specialists' in the UK if friendships, loyalties and obligations didn't camouflage them so much.
Personally I'm betting it's the carbs. The whole package needs setting up on a rolling road. Simple as that.
If they are the modern 'vintage' Spanish made 45DCOE-9s ( judging from the photos ) then I'm willing to bet they are the 'out of the box' settings / jets.
That would give you 36mm chokes, 145 main jets, 155 air correctors, 55F8 idles, 45 pump jets and F16 emulsion tubes. I think they have the 'short' 10mm stroke accelerator pump rod stroke too ( Weber recommended the longer 12mm stroke for the L-series ).
And therefore the setting will be way off what your engine really wants.
Let's be honest here, you would hear all sorts of anecdotes about ALL ( and I mean ALL ) of the so-called 'Z-specialists' in the UK if friendships, loyalties and obligations didn't camouflage them so much.
Sean Dezart said:
Personally I'm betting it's the carbs. The whole package needs setting up on a rolling road. Simple as that.
SeanDezart
Well-Known Forum User
Then my Count, there is nothing physically wrong with the carbs.........and any specialist, Z or not shouldn't hesitate to set them up on a rolling road with a gas-meter or at the least insist that the client do likewise.
Re anecdotes - yes I agree - perhaps I've another one as a car sold in the UK by...... as clean, straight etc has just been found to have serious accident damage.............
Re anecdotes - yes I agree - perhaps I've another one as a car sold in the UK by...... as clean, straight etc has just been found to have serious accident damage.............