Dellorto Carb Anti-Surge Washer

A MA article on tuning the PHBG Carb recommended removing the anti-surge washer the sits under the main jet, saying it can block fuel and cause a lean condition. Is this true? It's under the main jet, and I can't see how it would block fuel. If Dellorto put it there, it must serve a purpose.

Joe

Re: Dellorto Carb Anti-Surge Washer

Always trade them out

Re: Dellorto Carb Anti-Surge Washer

From what I can tell it's mostly used in off-road dirt bike style applications, don't think it's very useful for street bikes

Re: Dellorto Carb Anti-Surge Washer

Anti-percolation - if the vibrations of your engine is causing fuel foaming this is part of the cure.

Pretty safe bet that Dellorto did not purposely install a defect in all of the 100,000s of PHBG carbs they have produced, neither have they installed a feebee part that you can throw away just on a whim. As a manufacturer, I am sure if a part was only applicable to a small percentage of clients, they would sell it at extra cost as an option.

...just saying...

Re: Dellorto Carb Anti-Surge Washer

Rebel, I like your theory. I don't see Dellorto adding parts unnecessarily. If it's there, it must have a purpose for most users. The MA article on tuning must have made an error. Joe

Re: Dellorto Carb Anti-Surge Washer

It acts as a baffle just like a fuel tank or oil pan baffle, it keeps the gas from sloshing around to much.

Re: Dellorto Carb Anti-Surge Washer

The washer is so small, compared to the size of the float bowl, it would be hard for it to keep much fuel from sloshing. Perhaps it's there to protect the idle jet from getting splashed when cutting the throttle for a quick stop, and killing the engine. The idle jet is right below the washer.

Still not sure where the author of the PHBG tuning site on Moped Wiki got that the washer should be removed. He said "Remove it because it often blocks fuel to the main jet and causes extreme lean conditions. "

Re: Dellorto Carb Anti-Surge Washer

The wiki unfortunately is full of a lot of conjecture. If people are running the surge washer without issue they should update the entry!

Re: Dellorto Carb Anti-Surge Washer

I never was good at updating the wiki, I tried, I failed, I.m old, I have enough issues with the webnet, I am no Mike Zuckerberger you know...

> Mike Boyd Wrote:

> -------------------------------------------------------

> The wiki unfortunately is full of a lot of conjecture. If people are

> running the surge washer without issue they should update the entry!

Re: Dellorto Carb Anti-Surge Washer

Rebel, as much as the Wiki could exponentially gain from your knowledge being permanently added and categorized on here, you have already done more to help on threads over the years than almost anyone and I could never ask or expect that of you :)

hoping maybe OP will have success and be down to throw in some edits for posterity

Re: Dellorto Carb Anti-Surge Washer

Overpriced Parts /

> Joe T Wrote:

> -------------------------------------------------------

> A MA article on tuning the PHBG Carb recommended removing the anti-surge

> washer the sits under the main jet, saying it can block fuel and cause a

> lean condition. Is this true? It's under the main jet, and I can't see

> how it would block fuel. If Dellorto put it there, it must serve a

> purpose.

>

> Joe

>

> https://www.dellorto.co.uk/wp-content/uploads/2015/05/9779.jpg

It does make lean for me on light ported Puch polini 4 pedal 21mm phbg that has high 101jet (comes with 92 jet, 262 atomizer) and rich 264 atomizer and rich needle setting and a puch polini 19 mm phbg with rich 96 jet and needle setting but other bikes that I run closer to stock jet/parts

I had no lean problems so some bikes I run them some I don’t, washer is more needed for bumpy and off-road use,

One bike I have to run anti-surge washer and spring loaded float needle to stop surging (Spring loaded float needle is pretty cool too it helped surging and stopped staling on fast/emergency stops on a problematic bike)

Float height is so important, on some bikes/some carbs you need to have so high that it almost leaks ,

Re: Dellorto Carb Anti-Surge Washer

Roffman, so the anti-surge washer is making some engines run lean for you? Any theories why? The washer is held in place by the main jet, so that jet is below the washer. The washer shouldn't impede fuel to it. To the idle jet, maybe. See photo. When in place, the washer is held in by the main jet.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account