Weber part 100

[Enigma]

i know 99 questions have already been asked re setting up a weber but here is question 100 lol..

I know as a rule of thumb to speed up the tickover, then screw the mixture screw all the way in, then unscrew it a turn and a half as a sterting point!

I did this yesterday and had a job to start Tigger...I managed to start him by keeping my foot on the accelerator, then turned the idle screw some more until he would run without the aid of my foot...I then turned the mixture screw clockwise a little...(much worse) so turned it anti-clockwise a 1/4 at a time until although racing a lot was running smoothly.....I then slowed the idle down and went on like this until i achieved what to ear, Tigger sounded as smooth as smooth can be...I drove for 30mins or so and then slowed the tick over a little...it sounds great and performs lovely but the mixture screw is at least 3 whole turns out........is this ok, have I done it right? ...I have no timing light and even if I did I wouldn't have a clue what to do with it...any comments gratefully recieved

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[commeracer]

If it,s running ok, then it,s fine. But technically 3 turns out would mean that the pilot jet is too small. Assuming that it,s a fuel screw and not an air screw

"You,re only supposed to blow the bloody SLIDING doors off"

 

[Lulu]

Good answer that Tim, I was just going to say the same thing but seeing as I have no idea what it means I wont bother to say it. I didn't realise that the commer was a Jet and needed a Pilot and not a driver

 

[Enigma]

Thanks Tim..errrm? i wouldn't know the difference? as far as I know there is only 2 screws? a mix screw and a idle screw? I'll try and post a pic tommorrow to show which screws I'm waffling about lol ....I may well be completely doing something wrong lol .....How is Kermit coming along mate? you haven't posted for a while...

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[commeracer]

All carbs have 2 screws, 1 is to control tickover speed by way of slightly opening the throttle. The other is either air or fuel for the pilot mixture. Generally if the mixture screw is after the throttle its air, and if before its fuel. I,m not that familiar with Webers but all carbs work on the same principal

Kermits been a bit slow, due to waiting for bits and/or me being busy getting the Dodge/J4/Mini all mot,ed and a quite involved bike project going on. but normal progress will be resumed very soon

"You,re only supposed to blow the bloody SLIDING doors off"

 

[Enigma]

Well I'm guessing but by before or after I guess you mean in which order it all gets sucked ..the idle screw is first in that case lol and the mix screw is lower down the pecking order

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[Enigma]

and poor Colonel is bottom of the list:I[}]
( i guess it goes in order of what pays the rent)
So, what bike project mate[?] you have been very quiet and you are missed

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[commeracer]

No you still haven,t got it [B)]. Idle speed screw - controls tickover speed by opening the throttle slightly.
Idle mixture screw - controls idle mixture (rich/weak). this can be by either letting more fuel through (screw is engine side of the carb centre) or by letting more air in (screw is air filter side of carb centre)

I,m still about

Bike project is a monster Honda C90 [:0]

"You,re only supposed to blow the bloody SLIDING doors off"

 

[Enigma]

Well, I know which screw is attached to the throttle at least lol I know if I turn it clockwise it slows things down and I can see it moving the bit where the throttle is attached.......so, even to me that bit is obvious[:0]............its that other bvugger with the spring on it that bothers me........I'm frightened it will ''spring off'' and vanish forever lol

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[Enigma]

Ah! I know the C90....its like the C50 without the pedals lol......red and white? ....but how does one ''Monster it''?

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[commeracer]

Like this

One monsters it quite easily
I will start a new thread about it if anyone is interested

"You,re only supposed to blow the bloody SLIDING doors off"

 

[Enigma]

Ahh fond memories of scrambling around local woods along with various Vespas etc lol..........yeah, new thread please...along with the above we used to 'play' with a Bultaco 125 and a Yamaha 125YZ among others [}]

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[Panky]

quote:
Originally posted by Enigma

i know 99 questions have already been asked re setting up a weber but here is question 100 lol..

I know as a rule of thumb to speed up the tickover, then screw the mixture screw all the way in, then unscrew it a turn and a half as a sterting point!

I did this yesterday and had a job to start Tigger...I managed to start him by keeping my foot on the accelerator, then turned the idle screw some more until he would run without the aid of my foot...I then turned the mixture screw clockwise a little...(much worse) so turned it anti-clockwise a 1/4 at a time until although racing a lot was running smoothly.....I then slowed the idle down and went on like this until i achieved what to ear, Tigger sounded as smooth as smooth can be...I drove for 30mins or so and then slowed the tick over a little...it sounds great and performs lovely but the mixture screw is at least 3 whole turns out........is this ok, have I done it right? ...I have no timing light and even if I did I wouldn't have a clue what to do with it...any comments gratefully recieved

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According to this method you've got it just about right, Scroll right down to the bottom of the page.

http://www.glencoyne.co.uk/carbs.htm

3 turns does sound a lot though:I But if it runs smooth and returns a good MPG what the hell

How refreshing

 

[Enigma]

Thanks john...well just been out in it and its not quite right...but at least now i will feel a little more confident to fiddle about with it[8D]

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[Stan n van]

Here is the manual I got in the paperwork for our van. I just set it to what sounds like an OK tick over and then screw in the mixture screw until it starts to die then screw it out till it doesn't change the rev s anymore then in a little bit. Seems to work. I think there is a magic fuel to air ratio you are seeking which I am sure someone can tell you (is it around 14:1). I tend to have to adjust it in the winter as sometimes it stalls on roundabouts at the end of dual carriageways, a slightly higher tickover cures this (not sure if that is the right thing to do). If it sounds OK it probably is OK! Tweaking this is a pain with a bench seat:I

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[Enigma]

Wow! thats really cool...thanks for that Stan & van[8D] haven't had another chance to go play yet....[8D]

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