7 replies to this topic

[plantfitterRich]

Hi all! Iv been searching for ages and had no luck on this topic!

Iv been having problems with the engine running lumpy and flat spots etc, i changed the dizzy cap, rotor arm and spark plugs. i have also bought a Colortune. i set it all up tonight but had no joy! the spark plugs are black and the exhaust is also black suggesting to rich. the car is off the road so i am unable to take it for a drive to warm the engine.

The engine will only run when the choke is out and the revs are kept up as the timing is way off. but what one first?

is the choke giving me a false reading on the colortune? it sooted up in about 5 mins of use. bright golden yellow colour was seen.

the engines a 1275, stage one, BBW.

Any help greatfully recieved

Cheers Richard

[mk1leg]

Hi..!..Richard to set timing up............as fellows
1. remove rocker cover
2. hand turn engine over in correct order of rotation until no1 & no2 rockers are rocking this means no1 cyl is on firing stroke.(rad end)
3. remove dizzy cap and mark block with a dot of white paint opp rotar arm
4. replace cap and loosen dizzy clamp and turn dizzy until no1 lead is opp white dot and tighten clamp
5. replace rocker cover and fine tune with strobe light..................good luck......................

[minimender]

Don' know full cicumstances but this is what I do with a new build.

Adjust throttle stop so as engine will run about 1500 rpm when you shove the choke in. You may have to adjust fuel
a bit so as it will run.
Twist dizzy so motor speeds up or runs at its fastest.
Slow revs down on carb throttle stop adjuster and allow to warm up.
Set fuel mixture.
Check timing again by whatever method you favour.
Check fuel again.
Reset throttle stop for nice idle
Job should be done

[Doodle]

when i watched the guy at Aldon do mine, he cleaned everything up then looked like he tweeked everything a bit at a time until it came close, he put in a new condensor too, but thats becuase it needed it, and the overflow valve thing on the carb float bowl was replaced becase the engine was overfueling

Edited by Doodle, 01 February 2008 - 09:44 PM.

[cambiker71]

If it's running, then it can't be too far out, mark distributor position with a bit of tipex or similar so you know where you started, loosen the distributor clamp just enough to be able to turn it, start engine and carefully turn the distributor (without touching anything electrical, unless you like electro shock therapy) very small amounts until it runs smoother without misfiring, tighten clamp back up, then get it to somebody with a strobe timing light to set properly and finally have emissions checked/reset properly.

Edited by cambiker71, 01 February 2008 - 09:52 PM.

[dklawson]

In answer to your original question, always start with the ignition settings first. As for the timing, regardless of what is specified as "correct" for your engine, you can set the static timing for something between 5-8 BTDC and that should get it started. Static timing doesn't require special equipment and once you've got the engine running and warmed up you can either set the timing dynamically or use the methods described above. If you aren't familiar with static timing, download the PDF I wrote to walk people through it:
http://home.mindspri...taticTiming.pdf

If you have to use the choke to keep the engine running then your mixture may indeed be off. Assuming you've got an SU carb, get the engine as warm as possible after you've set the ignition settings, then stop the engine and set all the default (post rebuild) carb settings. Restart the car and adjust your jet settings to get the correct mix.

[minidaves]

I work to base settings, Then adjust from there,

take dashpot etc off carb so you can see the jet (the brass centre with the whole the needle drops into)
set this so its approx .5 to 1mm down from the flat part of the carb body

timinig set static to around 8 degrees, however some dizzys have an advance or 18 degrees built in if electronic especially, which can give you far too much adavnce, and these should be set to 2 degrees after tdc to protect your engine.

Once u have it running base, then tune it yourself or ask around and find a good rolling road, these guys if they do there job properly will maximise your engine potential and hopefully prolong its life.

HOwever if your really unsure of what to do then I would advise you get some help from someone who can show you

dave

[Big_Adam]

Well the yellow flame indicates rich mix. Same with sooting.

If you want a quick method to test if you need more advance then suck on the vac adavance pipe with the engine running,

If it speeds up then you need more advance,

Thats how I did mine.