Can anyone enlighten me why:
I have just installed new dual webers (36 on 1600 tp), but the engine now will not start.
It turns over fine but will not fire. I believe the coil is OK, as it was working fine before hand, I have checked the timing and all OK.
I have a checked the linkages and all OK, and have been using the procedure outlined on redlines web page to set up the mixture, but no joy.
Anyone suggest anything?

fuel and spark are the key.

try taking off the filters and opening the throttle right up a few times to get the accelerator pumps working. You should be able to see and smell fuel vapor in the throats. this will tell you if you have fuel.

if that's ok, check the linkage, it might feel like it's working but not be open the throttles.

then pull one of ya plug leads and do a test using a screw driver to ark the spark against the block.

once you have both, the car should start...fingers crossed:duh

I checked, and have spark from the coil, also tried two distributers (I had put on a new one, and wanted to rule out it was faulty - but the old one still didn't help).
I put fuel down into the tops of the carbs.
I got a slight kick once, but it seemed to be backfiring.

This is the third weekend in a row I've been mucking around with this - not happy Jan!

sounds like your fuel system isn't working somewhere. is the fuel pump ok? is the filter blocked?
are the carbs full of fuel?
disconnect the fuel line and make sure there is fuel in it. next check the oulet of the pump, then each fuel line going to each carb.
be systematic.

if there is fuel there, then do this.

take the filters off. get some one to floor the throttle 4 or 5 times. watch while they do this to see if the accelerator pump is spraying fuel into the throat.

if all this is ok, then try and turn it over.

if it kicks but then dies, the automatic chokes or the idle set up are probably the issue.

just a thought, are there fuel cut off solenoids on each carb? are they hooked up to the ignition? if they are not, the carbs are not letting any fuel out when the motor is turned on.

oh, you've been swapping dizzies eh?...line up top dead center then redo ya timing.

let me know how you go.

BTW are the points adjusted right? and are they clean?

I had some issues when I put twins on my 1600tp for the first time the fisrt problem being that I connected the fuel pump back to front, the second being the timing being way out. As pete said I'd do the tappets, points, and ball park timing. If you are lazy just get someone to crank it while you slowley rotate the dizzy if it farts and splutters then you are close but the fuel is probably the issue.

There is fuel at least until the T piece before going to each carb. I know this because I have a filter there and I can see it.
Timing is set OK. Fuel pump is OK. Filters are new. Points and other contacts in the distributer are all clean.

I don't think that the carbs have cut off solenoids, there is no electrical connection to them (italian 36 IDF webers). But where would this be if they were there?

I had a thought, the sping loaded thing in the centre of the carb, on the oposite side to the mixture screws is hitting the fan shroud and cannot turn. Would this be stopping the feul from being pumped into the carb?

look at a diagram and figure out what it is. that could be ya problem.

have you spoken to the shop that sold them to you? they might have some ideas as well.

can you post some pics of the set up and I'll keep thinking about it.

here are the photos of the part I was talking about.
On the other side of the carb, more or less directly in line is the accelerator pump.
It is only fouling the fan shroud on one side, on the other it is free and doesn't move when the accelerator is operated anyway.

Also I got it to fire up this morning, by working the accelerator pedal quite a lot, but then it was running really rough and back fireing alot and stopped when I stopped working the accelerator.

another photo of the part fouling the fan shroud

do your timing again and try again.

back firing probably means the ignition is not working as it should.

at least it fires now...small victory though eh:o

checked the timing again, its fine.
Now won't start again.:cry

I think its mechanic time this week - getting sick of walking to the train station.

yep,

sorry I couldn't help more.

bet it's something simple and frustrating :cussing

do you have a 009? try moving your timing mark 90 degrees or make absolutely sure that 1 is at TDC (firing) and verify that the plug leads are in the correct order 1-3-4-2 (from memory) I'll put money on it being ignition good luck

something you said...I had the firing order wrong on the dizzy - I had thought of this and had thought I had checked it OK on my type 3 to see if it was the same, obviously I made a mistake.
I couldn't find it anywhere in the John Muir book either.
But after reading this I just ran out and swapped the leads over on the dizzy and wham bam thank you maam!
It fired straight up. Its a little rough -but I haven't adjusted or balance the carbs yet.
I feel much better now - thanks.

Kafer

You still have the choke/fuel enrichment thing on the carbs.

NORMALLY this is taken off an a block off plate put on.

IF it fits - no real drama, but it normally fouls with the shroud.

MAYBE - NEXT time you pull the carbs you can put them on.

Glad to hear it is running.

Now to jet those suckers!

yeh!, I knew it would be somthin silly, good on ya Kafer Lover!:thumb

With the choke/feul enrichment thing, should it be in the position it wants to be - ie it is spring loaded. Because it hits the shroud, I can either jam it open or closed. (I assume closed is its normal state and open is working against the spring load)
I guess it should be closed, but can anyone confirm?
Thanks,
Tim

Um hopefully someone knowledgable will come along with an answer, but in the meantime, here's a free bump...

On my stock solex's the choke flap should be open under normal running conditions. It is shut at the start to allow more fuel in (with respect to the amount of air), because it restricts the airflow. The flaps are then opened slowly as the heating element warms up, once again allowing proper airflow.

I understand that these choke thingos are not entirely necessary on type IV's, and guessing by the fact that 'these are usually blanked off', I presume your engine would be fine with them gone too. I'm guessing here, but I'd be tempted to set them to be always open. Don't want over-rich running all the time, that's bad isn't it?

Cheers mate,
Aurel

so when nothing is attached to these things are they open or closed?
Anyone know?

as is, is fine

Just better to take em off so they dont open

glad to help its easily done and it's a lesson you will never forget (we've all done it)

I'm afraid my joy was short lived.
I can't get the bloody things to run smoothly:cry
Still a bit of back firing and when I take my foot off the gas the engine cuts out.

Looks like I am still walking, at least until this weekend when I get the chance to have a decent play with them.

[Edited on 13-9-2004 by Kafer Lover]

firing order is 1-4-3-2.............not 1-3-4-2.

Change to that and it should fix your problem.

Well I just went out and tried that. I think its a bit better, but still I guess I need to play around with the mixture to get it idling smooth, as its still a bit rough.
Cheers mate.:beer

Can you tell what jets you have in there now???

Speaking from experience. If you are not a pro, get them jetted by a pro. People can tell you millions of jet combos that should work (all respect to blue74L, you are a legend) but unless you are there and can hear and feel an engine you can't tell if it's running spot on.

Make sure the "expert" really is one too...

I screwed around with my Weber by myself and so-called experts and wasted hours and hours and heaps of cash too. I took it to a real expert and a day later and $300 and it was running beautifully. Sometimes you just have to give in. This is coming from one stubborn bastard

Just my opinion.

Another thought - are there any open vacuum fittings on the carbs? If there are, that will certainly affect your running!

this sounds like a problem i had last week (i think it was last week) car would only run if i tapped the accellerator all the time and was rough as guts i fiddled with the carbie for ages and couldnt work it out because it seemed like a fuel problem. turned out it was the points. you say u swapped dissys and everyone has said to check timing. i assume u would have done this too but if u havent check that your points are set right and arent closed when they should be open.

Nick