fitted a dellorto and still no joy

[leehuggy72]

hi all,

bought a dellorto as i had issues with my keihin 28pwk

its a 28mm phbh

118 main
50 pilot
av266 atomiser
40 slide
x7 needle
70 choke jet

fitted to a mugello 186 with a scootrs pipe, bgm stator and af flywheel
My keihin would tick over fine but would bog down as soon as i tried to pull off.. tried every thing with no luck.

so i bought a dellorto

problem i have now is the carb just spits out fuel especially from the choke hole at the venturi opening ...

i had a similar problem with the keihin.. it was as if the compression/timing was pushing the fuel away from the carb and not drawing it into it.. i've had the timing checked and strobed plus the squish is ok and the plug gap set to .5mm..
i'm really losing faith.
the amount of fuel it kicks out is quite alarming. i just want to get it mot'd and this is doing my head in

please help

[J1MS]

Make sure the choke is closing off completely and if it is, then it might be a problem with the float valve not shutting off or the float heights being too high or the float weights being too heavy. other than that I'm not sure what else it can be.

[leehuggy72]

Make sure the choke is closing off completely and if it is, then it might be a problem with the float valve not shutting off or the float heights being too high or the float weights being too heavy. other than that I'm not sure what else it can be.

thanks for the reply j1ms

the scoot won't start with the carb at all.. (my keihin at least did tick over and rev ok)
the choke opens and closes fine,
the float valve shuts off the fuel ok
the float height is 24mm from carb body to back of float when checking float height do you let the float settle on its own or do you push the float which in turn pushes the needle to shut , then check the height
as i've put the carb on a flat surface then measured the distance even tho there is some play towards the needle

the float weights are 9.5 grams

[J1MS]

The float settles itself to measure, this can be done for a carb with floats attached with the carb resting on its bell mouth so the float sits at 90 degrees or without floats and just float arms with the carb upside down, normally a two stroke runs on light floats with a lower fuel height in the float bowl than a four stroke, but I cant remember which weight I normally used in a PHBH, as I haven't written anything down from the last one I set up and I don't have one here.

They are normally very good, and easy to set carbs, but most run on either X7 or X13 needle with an AQ 266 or 264 with a main jet from around 110-125 on a 55 pilot jet air screw somewhere around 1.5-2.5 turns out.

Daft idea but maybe empty the float bowl of juice, clean the pug and kick the engine with the plug out to clear fuel.

Replace plug, turn on fuel for about 5 seconds then turn off. and it keep switched off, now try kicking the scooter over, then and only then turn on the petrol when its running. It might take a couple of tries draining and cleaning the plug then refilling the float but if it finally starts then its most likely fuel height problems in the float bowl...

All the best of luck.

[leehuggy72]

i'm going to take the carb to pete at beedies see what he thinks

its done my head in

thanks j1ms

[minotaur]

just a thought, is the exhaust endcan clear, had a problem years ago when my webbing blocked it up and scoot would only just tickover, but not rev............