Weber check list

[spridget]

Hi guys

I have dismantled my Weber?s. I?m still searching why the engine doesn?t want to throttle anymore after a while (see here : elan-f15/engine-trouble-t23224.html ). I?ve got also a brand new distributor from TTR to fit (see here : elan-f15/which-electronic-ignition-choose-t23307.html ) , the Weber out will help to fit it easily
I?m planning to check all the jets of the weber but they are 151 series so I don?t have the chart on the Workshop manual which only mentions those for a 31 (or 18 ?)
According previous owner, engine has been rebored +40
So what do you think I have to control ? and what are the best specs ?

I have forgotten to mention that two thackeray washers are broken, what are the best replacement, other Thackeray or rubbers mounting ?

Thanks
Franck

[spridget]

Hi all

Well a lot of views but no reply ... Not sure my explanation was very clear
So this is what I have found on my carbs :

The same as specified in the workshop manual for S/E early type :

Primary venturi (choke) : 32 mm
Main jet : 115 mm
Air corrector jet : 150 mm
Emulsion tube : F11
Needle valve 1.75

Differences :
Idle jet : 50 F8 ? 45 F8 specified in the workshop manual
Pump jet 40 mm ? 35 mm specified in the workshop manual
Starter petrol jet 85 F9 ? 100 F5 specified in the workshop manual

I?ve bought the correct idle jets and pump jets from a seller on ebay
I think not necessary to change the starter jets

I?m waiting for these new parts

Any thought ?

Thanks
Franck

[trw99]

Franck

Get over to Side Draught Central at: http://groups.yahoo.com/group/sidedraft_central

Keith Frank is rewriting the Weber tuning book and getting close to 'perfect' running carbs. You will find answers to your set up in the old posts and lots of advice of the knowledgeable listers there.

Tim

[jk952]

just an observation...
"Differences :
Idle jet : 50 F8 ? 45 F8 specified in the workshop manual
Pump jet 40 mm ? 35 mm specified in the workshop manual
Starter petrol jet 85 F9 ? 100 F5 specified in the workshop manual"

typo or am I reading incorrectly, or a different manual, or different vintage?

the 0471 manual on pg 14 shows 50F8, 40mm, F.5/100, respectively for 32mm S/E

the earlier manual I have has totally different no.'s for Stage II config. but this may not be S/E as not described as such just 115 hp??

I have the new 151's but a different config. as standard cams, though mine may be running a bit rich; had a coil problem so will check again after I run it a bit longer.

jk

[UAB807F]

Hi Franck,

I'm not sure about the carb spec changes although my thoughts would be to set them up as per the workshop manual before getting concerned about different jetting for an overbored engine. I'm not sure that's needed anyway unless there are also cam changes.

The reason I say "not sure" is because I thought the original problem was that you started off ok but after a short while the engine wouldn't rev much above 2000rpm but after cooling down it was ok ? If that's still the case and you've ruled out petrol starvation then as the jetting stays the same regardless of engine temp then I'm struggling with the jet changes quoted. I can see that an over-rich mixture would start ok but might be poor once the engine has warmed up, but I think you'd still rev above 2000 though.

If you've ruled out the fuel delivery as a problem and the pump is working ok, the filters are clear (and you have petrol in the tank ) then I think I'd be checking the electrics. You said you'd replaced the coil (forgive the impertinent question but is it the correct spec ? ) so I'd move on to the distributor/points/condenser/timing and make sure they're ok. Final thought - if you have the carbs apart, were the float heights correct ? IIRC float height does make a difference to the fuel delivery & mixture.

Brian

[spridget]

Thanks guys for replies

Tim, I have subscribed on Wahoo but it?s a very specialised forum, although I found interesting information

Jk, that?s why I asked your opinion, my workshop manual (the Lotus Elan +2 one ) shows what I?ve wrote but these spec are given for Weber 31 not for 151.

Brian, you?re absolutely right ! I?m still searching to resolve the problem
And to be honest, I?m in hope to resolve it and other ones ! like fooling sparks, heavy consummation, a hole between 2000 and 3000 rpm, some erratic explosions when cold ...
The carbs are apart to check the pump and for an easier distributor change, and as they are apart I have checked them too
The float heights seem to be good : 12 mm as stated for a 151 with plastic float
So the truth is probably elsewhere ! and may be the carbs are definitely right

Yes I have replaced the coil for a Lucas sport, not sure about ballast or not ballast so the question is not impertinent
May be the fault is just due to the condenser who didn?t like the new coil ...

I?m still learning ....

Time is missing but I hope working on the car next week to fitting the new parts

Last question, I haven?t checked the pump yet then should I have to take off the entire pump or just the dome for inspection ?

Oh , yes I will fill the tank up ! The other benefit is a good fuel smell everywhere in the house especially liked by the wife !

Thanks again
Franck

[UAB807F]

As far as ballast/non-ballast coils go I don't know about the +2's. My S3 has non-ballast and my Europa originally came with a ballast system but I changed it over to non-ballast so both TC engines would be similar systems (and hopefully I wouldn't get confused between the cars)

Thinking about what you've listed and seeing how you have very easy access to the distributor with the carbs off, it might be worthwhile stripping that to make sure the bob-weights are free to move and you get a smooth advance curve. To be honest I've never noticed them seizing on mine despite long periods of inactivity, but it would be another tick box to complete whilst you have easy access. Of course with a new electronic ignition distributor fitted it would be an academic question, but assuming when you re-assemble with new parts and it all works fine it would be nice to know what the fault was.

Brian

[spridget]

Hi

Well the new TTR distributor is on the car with new coil and wires
The carbs haven bee re-jetted as stated on the workshop manual ... and ...and
the engine doesn?t start !

However, there is sparks on the plugs
The plugs weren?t full of petrol


I wonder if the distributor could be half a round turned ?

My car is neg earthed
There are 2 wires from the distributor, I have connected the black one to the neg on the coil and the red on the +.
On the + on the coil is also connected the Red and green wire (the positive wire coming through the tacho)

I haven?t made the static advance check up with the lamp as I used to do with a point distributor, should I have to do it ? how ?

Thanks for your advices !

[UAB807F]

Hi,

As you infer, if you're getting a spark at the plugs then the first thing I'd do is check that the timing is set properly. I don't know anything about the TTR system, but I assume that you insert the distributor into the engine block the same as you do with the OEM one - ie set to TDC, rotor arm pointing as per manual & it rotates to #1 cylinder on the distributor cap as it meshes ?

My most common mistake in that area is to get it firing on the wrong side of TDC because I've not had the rotor arm correctly set before replacing the distributor, or I've had brain fade and not had the engine set to TDC for the #1 firing stroke. You think I'd know better by now but I still seem to manage it.....

My set up is the pertronix ignition and the wiring sounds the same as yours, black to coil -ve, red to coil +ve. I seem to recall setting the static timing with a bulb connected between engine earth & the distributor side of the coil when first installed, just to get it running before using a timing light.

Brian

[AHM]

Have you checkes that your fuel pump is not full or "rust sand". Not just the gause but the chamber of the pump - fills up with sand so you get less volume of fuel with each stroke.

Easy to undo the thumb screw and take off the glass bowl and clean.

So you are running at 2000 rpm what happens when you put your foot to the floor? Revs drop/sounds harsher/ engine dies - lack of fuel? Or, missfire - plenty of juice but no spark to ignite it?

Simon

[twincamman]

I found the float level drop was critical in the 40 dcoe . I also found the battery neg ground to the chassis is critical and believe it or not thats where the problem was, once I cleaned it up 2 years of grief was gone as the car runs a treat -----and I blew 1000 bucks on new carbs in desperation so I left them on but the old ones worked after the ground was established ed ---- the Fn battery ground ;who would have thought --SOB BRITISH ELECTRICS -ed

[nebogipfel]

.......SOB BRITISH ELECTRICS -ed

I think you will find all electricity needs good conduction paths

[twincamman]

Welllll maybe so ....but I'm sure it was a lucas ground or Lucas electrons ..Ed

[spridget]

Brian : I?ve got the same though about a bad timing, however that?s what I?ve done : engine set to cylinder 1 to TDC and rotor arm on the right plug on the cap ... I?ll check once again
I?m sure you know better by now !

I?m interested by your static timing setting : I assume the bulb must be connected to earth and on +ve from the distributor ? I don?t really understand the black wire role between coil and distributor


Simon : To be honest I haven?t undone the glass bowl, I was thinking it could leak after ! but as the carbs are back on the work bench, I will have a look on it

Ed : I?ve checked the float level, on the 151 they are supposed to be at 12 mm high with the seal fitted. The neg ground is correct I think, I?ve got a little bit more than 12V on the switch . But as you certainly know Joseph Lucas was the Prince of Darkness, so I will check one more time !

Thanks mates

I?m still learning

Franck

[twincamman]

You might need 13.5 or so in voltage as at 12 volts is a flat battery ..the thing should starton the second revolution . I timed mine 15 times and it was always the same jump the battery or replace it .....air spark and fuel ....ed