Choke Jet on PHBL 25

[Storkfoot]

I had no experience of the Dell’orto PHBL 25 until a few months ago.

I have struggled to get the starting and tick over right on a Stage 4 200cc. I notice that the starter jet (choke jet, not the pilot) is a 60 whereas, on the PHBH30 I have on my TS1, it is a 70.

The engine will be going on a dyno in the next week, or so, so I am not after overall jetting ideas, I’d just like it to start readily and tick over when I present it to the dyno operator.

Has anyone any experience of whether, say, a 65 or 70 would help?

[Cgt75b]

I’ve run a phbl for a number of years and never had the need to change the starter jet, is it something related to your filtering system?

[Storkfoot]

I’ve run a phbl for a number of years and never had the need to change the starter jet, is it something related to your filtering system?

What engine is your PHBL25 on, Paddy?

It’s not either of the filters in the carb or tank. I have tried a couple of slides, atomisers and needles, as well as a fist full of pilots. At one point, I had an air leak which confused matters. That’s why a dyno awaits

[martyn dwane]

I ran a PHBL 25 on a stage four with a RS Clubman thru a modified air box (drilled holes and swan neck cut out) never changed the choke jet.

[Cgt75b]

I’ve run a phbl for a number of years and never had the need to change the starter jet, is it something related to your filtering system?

What engine is your PHBL25 on, Paddy?

It’s not either of the filters in the carb or tank. I have tried a couple of slides, atomisers and needles, as well as a fist full of pilots. At one point, I had an air leak which confused matters. That’s why a dyno awaits

It’s on a piston ported cast 230

[Wack]

I had a 25 once that wouldn’t start on choke and when I took the jet out it wasn’t drilled correctly from the factory.

[Storkfoot]

Just to finish this post off, the standard choke jet is fine. I had other issues which were adversely effecting starting and tickover.