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Adjusting a PHBL 25

PostPosted: Thu Jun 04, 2015 3:29 pm
by muddy
The tickover is a bit low and starting isn't the best so I thought I'd adjust the carb settings. There's 2 adjusters 1 larger one with a spring. The problem is were ever I tun these 2 screws there is no effect on the engine, any suggestions please.

Re: Adjusting a PHBL 25

PostPosted: Thu Jun 04, 2015 9:03 pm
by 2ndtimearound
I`ve just had a lot of messing with mine on a fairly standard TV175 see post below yours & hope I have now sorted it more or less. Have a look on the MB tech site , as there is a lot of info on there about the carb set up.
Basically your big screw should adjust the slide up/down depending on whether you screw it in/out & should increase/decrease revs (take the bellows off & you can see what happens). The small jet at the back adjusts the fuel at tickover/low speed & richens mixture screwing it out, weakens screwing it in. This screw shouldn`t be screwed out too far or it may fall out - have a look on the Broadhurst site - they will take you through it.

Happy reading/fiddling.

Re: Adjusting a PHBL 25

PostPosted: Thu Jun 04, 2015 10:15 pm
by muddy
Thanks for the info mate

Re: Adjusting a PHBL 25

PostPosted: Fri Jun 19, 2015 7:10 pm
by Cgt75b
The anti surge washer in the float bow, can this be removed without issue, or does it need too stay in there ?

Cheers

Sorry for plonking on the end, didn't want to start another thread.

Re: Adjusting a PHBL 25

PostPosted: Fri Jun 19, 2015 8:40 pm
by rossclark
I'd say dellorto put that there for a reason, leave it be.

Re: Adjusting a PHBL 25

PostPosted: Sat Jun 20, 2015 2:20 pm
by Cgt75b
Fair point taken. But the question still remains is there any ill effects to running it without ? Innocenti built scooters that shouldn't go 100 mph but some do!

Re: Adjusting a PHBL 25

PostPosted: Tue Jun 23, 2015 12:54 pm
by 2ndtimearound
Maybe I`m blind, but I`ve had my PHBL 25mm to bits quite a few times changing jets & I`ve never seen an anti surge washer in the float bowl - I assume looking at the parts diagram it just sits over the jet to stop fuel slopping about when you`re going for it? :oops:
For what it`s worth, mine has been on a 190 cylinder & I never noticed any bad running on acceleration/cornering.

Re: Adjusting a PHBL 25

PostPosted: Thu May 12, 2016 11:07 pm
by northernpete
Can I ask what manifold you guys are using....I have a phbl 24as carb (same body I believe) and can't get a manifold to fit ( solid mount,185 barrel) :?