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28mm delly

Posted: Sat Jul 04, 2009 6:16 pm
by lammydave
My 186 mugello is running fine (dare i say that) the set up is...

46mm AF rayspeed

28mm phbh carb with...
40 slide
X7 needle (3rd clip, but may reduce to 2nd)
118 main
50 Pilot
70 Choke
AV 266 atomiser

but......

i noticed that the float valve is a 200, and most opinions say at least 300

question is... if this set up is working (pulls well, plug colour right) what are the implications of changing to a 300 ..... or if i leave it, what are the future implications... decisions, decisions..... :roll:

Re: 28mm delly

Posted: Sat Jul 04, 2009 10:07 pm
by the-brickie
If it aint broke mate... BUT if it blows up I didnt say that :D

Re: 28mm delly

Posted: Sat Jul 04, 2009 11:40 pm
by Knowledge
If you had a problem with the float jet, it would manefest itself with running weak and perhaps pinking. From your description, it sems you're not having either of these problems.

As Man-of-Brick says, if it ain't broke.....

(but if you wanted to convert it to 300, it is probably only a matter of drilling out the existing jet from a 2mm hole to a 3mm hole)

Re: 28mm delly

Posted: Sun Jul 05, 2009 7:05 am
by lammydave
thanks, guys...

i have a spare 300 ... initially the scooter ran weak and holed a piston... it was then found to have an inlet manifold leak, so sorted that and changed the sterling exhaust for an AF rayspeed....

things are ok now....

does the float jet control the rate at which fuel enters the float bowl??

Re: 28mm delly

Posted: Mon Jul 06, 2009 4:42 pm
by Knowledge
does the float jet control the rate at which fuel enters the float bowl??
Yes. The bigger the hole, the faster the rate of flow. It is the float's responsibility to ensure that it shuts it off again.

Re: 28mm delly

Posted: Mon Jul 06, 2009 5:11 pm
by soosh
Dave,i always use a 300 jet,as you know there is no need to drill out,just screw the jet in.Allowing a better rate in is always safer and it will shut off ok.A lot of dealers will supply a 300 as standard when you buy a 28/30.Ive even used a 350 once and its still fine but you should be fine on 300.

Re: 28mm delly

Posted: Tue Jul 07, 2009 10:07 am
by paul213
if you drill a 200 out to 300 they can stick shut as the hole is right on the very edge of the rubber tip from 250 up the needle is bigger in diameter .
if you do change the assembly dont forget to check the float height when I changed mine it made the level in the float bowl low . cant remember where I got height info from but was from a link on here.

Re: 28mm delly

Posted: Tue Jul 07, 2009 9:02 pm
by byron
paul213 wrote:...check the float height when I changed mine it made the level in the float bowl low . cant remember where I got height info from but was from a link on here.
good guide here

Re: 28mm delly

Posted: Wed Jul 08, 2009 5:25 am
by lammydave
thanks for the help, guys...

looks like the 300 is going in......