Changing the fuel mixture on CG

learnerbiker · Renault 5 Driver Joined: 05 Nov 2007 Karma :

I couldn't start the cg today and noticed there's black deposits on the spark plug (fitted three weeks ago). It was so caked it wouldnt spark. I've cleaned it off and it starts ok now but it will undoubtedly do it again.

It must be running rich?

Anyone know which direction i need to turn the fuel/air mixture screw on the carb to make my cg run more lean? How much do i turn it?

I only ever use the choke for a few seconds to get the engine started so i know i'm not leaving the choke on for too long which i know can cause this.

here's a cg engine if it helps, this pic is newer than my engine.

https://w1.bikepics.com/pics/2005/08/29/bikepics-418380-800.jpg

Also the bikes top speed is about 50-55, i know its a slow bike but every review i've read says it will do 70 almost, is this because i'm over fueling? The bike doesnt top out, just takes an age to go faster, got 60 out of it on a loooooonnnggg straight.

As always i appreciate your replies. Thumbs Up

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I ride a divvy 600 Smile

Paddy Blake · World Chat Champion Joined: 29 Jun 2006 Karma :

Check the air filter it might need a new one.

Paddy.

learnerbiker · Renault 5 Driver Joined: 05 Nov 2007 Karma :

When i bought the bike i taken the air filter out and gave it a clean then put it back, its the old wire mesh type. So i think that should be ok... Confused

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I ride a divvy 600 Smile

19van71 · Spanner Monkey Joined: 04 Dec 2007 Karma :

I'm pretty sure it's anti-clockwise. I'd try a quarter turn at a time and see how it goes. Good luck Thumbs Up

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Living the dream....on my little 'ol CG125 Very Happy

Paddy Blake · World Chat Champion Joined: 29 Jun 2006 Karma :

Any chance of a picture of the filter as I cant really remember it that
well.There was also a problem where the seat could block the air inlet.
Is the seat good.

Paddy.

Paddy Blake · World Chat Champion Joined: 29 Jun 2006 Karma :

I think the air mixture screw is 1 and 1/4 turns out but that will not
fix your problem because it will not cause the plug to be the way you
say it is.

Paddy.

virus · World Chat Champion Joined: 17 Aug 2006 Karma :

the pilot air screw (little one right at the front of the float bowl) is set to 1 1/4 on the early japs and 1 3/8 on the Brazilians, after that there is no mixture adjustment apart from changing the position of the circlip on the needle.

id suggest getting a new air filter just to rule that out, check the pilot setting and then going for a long ride using the entire rev range to see if there are any flatspots, if there consistent in every gear from 1/4 throttle onwards then you need to adjust the mixture my adjusting the circlip height, up to lean it off and down the needle to make it richer.

Cheers
John
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own: 81 xs1100g...
owned: 85 rat CG (sold), 91 GS500e (stolen), 84 gsx400f (scrapped), 81 z250 (siezed, siezed, scrapped), 83 cb250rs (sold), 84 gpz750r ratfighter (killed) 84gpz400 (sold), '80 cb650 ratfighter (wrote off) 95gsx6/12f ratfighter (killed) 91 xj900 (sold)
stinkwheel Well I just had my hands up a pigs fanny. Which makes your concerns pale into insignificance.

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

If you like ride your bike more gently, try running a slightly "hotter" plug, which means using a plug with 1 number lower than the one you have now. Change your 8 grade plug for a 7
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy