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Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 6:28 am
by paulnobodyimportant
As Eden said, putting a good advance/retard unit on will improve low down revs. But going back to your immediate issue, its jetting. I've persevered with jetting over the last few years and I've sorted out the practicalities of how to do it. It can be laborious, but once you get the hang of it, you feel good and your scooter feels the same. In the main, I've followed the detail given on CamLams site, see link below.
http://www.lambretta.co.uk/downloads/carbsetup.html
And for bedtime reading, see this Dellorto guide on how your carb works at various revs and what to tweak
http://danskkartingcenter.dk/dellorto_m ... _guide.pdf
Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 11:29 am
by alanscottj
Thanks everyone for your help, much appreciated. The scoot has been dynoed so I know the jetting is right it's just always been a bit boggy as I say at 0-quarter throttle. Gonna open the carb and see what's in there jet wise and get back to you
Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 11:43 am
by Minority
Changed my 30mm PHBH for a PWK copy and found it was smoother and more responsive from low throttle openings. I think it's supposed to be one of the benefits of a flat-slide or D-slide type carb.
Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 12:10 pm
by mick1
^ agree. just changed a 30mm PHBH on my Avanti for a Mikuni TMX 35 (D slide/flat slide) and the difference is amazing. It has totally transformed the low rev's and spitback and is a much easier ride around town.
Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 2:07 pm
by alanscottj
I think my wife will divorce me if I change anything again and need to get it dyno'd again! Think I'll just try and get it the best I can and live with it
Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 4:50 pm
by eden
Yanker wrote:Stick one on yours then? Eden, Oh no I know what you are going to say...no not that the other thing you tw@7
ive got one on mine
Re: How to clean up low revs???
Posted: Sat Apr 11, 2015 7:34 pm
by alanscottj
Cleaned carb and found 55 pilot so I have swapped it for a 53, initial run seems ok, think my air screw needs resetting now though as I have been farting about with it
Re: How to clean up low revs???
Posted: Mon Apr 13, 2015 4:56 am
by onthelam
Minority wrote:Changed my 30mm PHBH for a PWK copy and found it was smoother and more responsive from low throttle openings. I think it's supposed to be one of the benefits of a flat-slide or D-slide type carb.
This I find interesting as I think PWK carbs are plentiful here as they are on Honda and Yamaha two-strokes.
Re: How to clean up low revs???
Posted: Mon Apr 13, 2015 4:58 am
by onthelam
alanscottj wrote:Cleaned carb and found 55 pilot so I have swapped it for a 53, initial run seems ok, think my air screw needs resetting now though as I have been farting about with it
Just curious and sorry if this is a dumb question but are you setting up your air screw in conjunction with the idle speed screw in the conventional manner?
Re: How to clean up low revs???
Posted: Mon Apr 13, 2015 7:30 am
by Minority
onthelam wrote:Minority wrote:Changed my 30mm PHBH for a PWK copy and found it was smoother and more responsive from low throttle openings. I think it's supposed to be one of the benefits of a flat-slide or D-slide type carb.
This I find interesting as I think PWK carbs are plentiful here as they are on Honda and Yamaha two-strokes.
I'm using the OKO version and so far I think it's a great little carb. However I think the copies can be of variable quality