7 replies to this topic

[happydude2012]

Im booked into the rolling road on 3rd Sep to have the carb tuned.

 

I tried a COLOURTUNE kit yesterday and have completely screwed the mix up - spent 3 hours on it trying to get this "Bunsen blue" and realised theres absolutely no chance on a well used road engine.

 

They are absolutely sh*te according to the rolling road crew and I am inclined to agree - bloody waste of time and money.

 

The idle is lumpy flat spot hell and although it wasn't great before its even worse now and ive no idea how to get it back.

Im more annoyed at myself for doing this.

 

Ive put new plugs in and im essentially having to adjust the mix now by looking at the plugs,

Any tips on this?

 

I should state I don't mind being at the richer end of the correct range, im just worried about being too lean.

 

Thanks.

Edited by happydude2012, 23 August 2018 - 12:33 PM.

[nicklouse]

if the needle is wrong you will never get a blue flame.

 

they are not ******* they do what they are meant to do very well IE showing up that the set up is wrong.

[Retroman]

If its not broke don't fix it ...?

 

Take the carb dash pot top off, screw the jet so that it sits flush with the bridge in the carb

 

Turn the jet down 2 turns [12 flats]

 

Start car warm it up

 

Set the idle to a fast idle [1150-1200 revs]

 

Lift the piston in the carb using the lifting pin on the side

 

If the engine dies its lean

 

If it revs up a lot its rich 

 

It should rev slightly then settle back to the fast idle tick over, so aim for this

 

Adjust the jet so its correct

 

I use colourtune regularly away and find them really useful, like me it does what its says on the tin

[gazza82]

'course the rolling road team will knock them .. that's what they and garages charge you a shed load to do ... g*d forbid we get clever enough to do it ourselves .!!.

[happydude2012]

well, it idles badly anyway and the last Aldon session I had they charged me a bucket load for a rubbish job in my opinion - put some old tatty HT lead on it which was clearly well used, and charged me £30, then processed to "modify" the needle and not tell me what they did to it.

£160 later my car still ran like crap.

Not in keeping with their reputation but enough to put me off ever going there again.

 

whatever the general opinion is, for my application this thing has fallen on its backside, likely user error im sure.

Not having a rev counter doesn't help either actually in general, I need an aftermarket one I think.

 

I can see the use of it - and I understand how it works, but as I said in anther post im sure my carb needs work anyway and ive got myself really peed off with it.

Tried to richen it to yellow which worked, but on weakening the mixture, it never went completely blue - not sure about the revs either which again was a pain.

out of interest, how do you guys use it?

 

 

Retroman, ill do as you say Saturday - thanks for the tip.

 

for the record im not paying full whack at the rolling road - bit of a favour, but still rather have someone in the know do it and explain it.

Also like to see whats changed since I last saw them 3-4 years ago just after rebuild -

[gazza82]

 

Not having a rev counter doesn't help either actually in general, I need an aftermarket one I think.

 

 

I bought one way back which was very simple to connect with just two wires: red to +ve on coil, black to -ve on coil (and an a 3rd for an internal light which is optional at this stage). Was also useful as I could hold it (it was a plastic housing) or wedge it somewhere(!) while working under the bonnet and I could see what revs I was doing without needing an assistant ..

 

This might be a possibility?  I am not recommending it .. just a suggestion ..

 

https://www.ebay.co....ccAAOSwL8lbR73J

 

You can also get timing guns with rev counters now I believe ..

Edited by gazza82, 23 August 2018 - 04:56 PM.

[happydude2012]

gazza! thanks for the tip! 

 

Ok guys about to once again hold my hands up and admit i was wrong.

Just got home, car ran like rubbish all the way back, felt like it was struggling to rev, poor power, bitty at idol etc - 

Checked out cylinders 123 and 4  spark plug, covered in a white bone like coating - too lean?

Whacked the colortune straight on, white/blue colour immediately, turned mix screw, revs went up a bit, smoothed out, flame was blue.

took the car back out and runs fine - did about 4 miles and looked at the plugs again, sort of light brown/greyish colour.

 

i think it worked.

[Retroman]

Sounds like progress and the plugs are the correct colour