Does this look to lean

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Main scooter: Lambretta LI 125 S3
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Mon Apr 17, 2017 7:58 pm

If your running in I doubt you've got that colour by running on the main jet so make sure your x7 needle is on the bottom clip, if it's still looking lean put a small washer under the clip to gain a bit more, maybe worth going up to av268 atomiser for the run in period then try a AV 267 + 120 main jet+ use a b7es plug (or equivalent) for the run in (300 miles)

That's what we've done with mine anyway and all is good.

Mr G in NYC
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Mon Apr 17, 2017 8:44 pm

I would change the needle to a X13 as it will deliver a rich mixture
at 50% throttle than a X7 needle.
X13 gets richer slightly later
X7 stays weaker longer .

Something to bare in mind .


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Mon Apr 17, 2017 10:52 pm

It looks lean to me but probably ran okay. Go up on the main main jet

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Tue Apr 18, 2017 9:12 am

doing a plug chop and reading the plug is not as easy as some might think, really you need a long hill so you can get some loading on the engine, hold it at a good speed with the throttle in the correct position for the range your checking, for a reasonable lenghth of time, then clutch in and stop,turn off engine and check plug colour, as said an older plug is easier to read as it has more deposits on it to change colour, my mate just holed a piston coming back from scarborough coming up hill no 3, i guess he was working his engine just a bit harder and longer than normal.

Chris in Margate
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Tue Apr 18, 2017 10:43 am

"Flying" can be a symptom of weakness.

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garry inglis
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Tue Apr 18, 2017 12:35 pm

Let us no how you get on with this

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Tue Apr 18, 2017 2:05 pm

mick1 wrote:get some masking tape and mark your throttle 1/8. 1/4. 1/2. 3/4

Run about a mile holding at the position then cut the engine and check the plug.

This will help identify if your, pilot, needle (+ clip position), slide, atomizer and main jet are ok

... please do note what Mick has said above as a plug colour from 1/2 throttle running will tell you sweet FA about how your bike is jetted at full throttle, and a full throttle plug colour will tell you nothing about lower throttle position.

A good pal did 1000 miles of running in at low throttle openings, with perfect plug colour, then seized it the first time he tried to run at full throttle! Please don't think that plug colour will tell you how your bike is jetted throughout the range. At best it can give you a vague idea of average but is more likely to tell you only about the last throttle position you were running at... provided you held it there, without throttle variation, for enough miles to take on a representative colour.


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Tue Apr 18, 2017 5:00 pm

Thanks Adam,I fully undertand what you are saying and take on board your advice.

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Tue Apr 18, 2017 7:28 pm

Got hold of a 120 main today,will try tomorrow.Have put the clip on the x7 needle on the lowest groove.
But,can someone please explain what the difference the atomizer,needle and slide will make.I.E.,is an av266 richer than an av 264?What will fitting a 40slide do compared to a 45?etc,etc.
I never ever had these problems with 2 stroke outboards,and my head hurts.

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Tue Apr 18, 2017 9:48 pm

A 40 slide is richer than a 45

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