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| | | | | Gas Bicycle Engine Kits Most motorized bicycle engine kits are either a 2 stroke or 4 stroke. Both need careful installation and setup, find out from our professionals here! | Dellorto PHBG replacement Jet Discussion at Motorized Bicycle Engine Kit Forum in the Gas Bicycle Engine Kits forum. Is everybody here aware that the jet in carby is replaceable? By chance I discovered that Dellorto PHBG main jets ...  | | 
06-24-2008, 07:37 AM
| | Senior Motorized Bicycle Builder | | Join Date: Jun 2008 Location: Australia
Posts: 97
| | Dellorto PHBG replacement Jet Is everybody here aware that the jet in carby is replaceable? By chance I discovered that Dellorto PHBG main jets are a perfect fit! The 70cc's really need a bigger jet. I am using an 0.85mm jet which compares to 0.70-something for the stock. I raised the pin clip to the highest (leanest setting) and then dropped it back by a 1/2 using a tiny washer.
That is another great tip: To get an in-between clip setting simply use a tiny washer.
Bigger jet is a massive improvement with the leaner clip setting needed for compensation. Now my engine is very smooth during the mid range and no longer starves for fuel at full throttle. I feel that idle may be a little lean however because it idles very high now.
Dellorto PHBG jets are cheap mine cost $5. | 
06-24-2008, 02:55 PM
|  | MODERATOR | | Join Date: Jan 2008 Location: Ashtabula county, Ohio
Posts: 4,072
| | Re: Dellorto PHBG replacement Jet I posted your other post about the delortos in "Classic Posts". It's permanent.
__________________ If it ain't broke, and you mess with it long enough, it will be. | 
06-24-2008, 03:58 PM
|  | Moderator | | Join Date: Mar 2008 Location: Tucson,Arizona
Posts: 2,495
| | Re: Dellorto PHBG replacement Jet Thank's for that tip RLorange...good info  | 
06-24-2008, 04:05 PM
|  | Master Bike Builder & Forum Sponsor | | Join Date: Dec 2007 Location: Duvall, WA PNW
Posts: 1,663
| | Re: Dellorto PHBG replacement Jet GREAT post. I'm familiar with the tiny washer trick - but I had no idea Dellorto PHBG main jets are a perfect fit......where did you get yours? | 
06-24-2008, 06:40 PM
|  | MODERATOR | | Join Date: Jan 2008 Location: Ashtabula county, Ohio
Posts: 4,072
| | Re: Dellorto PHBG replacement Jet See the classic post section, there's a link to several places as low as 2.11.
__________________ If it ain't broke, and you mess with it long enough, it will be. | 
06-24-2008, 08:32 PM
| | Senior Motorized Bicycle Builder | | Join Date: Jun 2008 Location: Australia
Posts: 97
| | Re: Dellorto PHBG replacement Jet Lots of places sell them try a minimoto dealer 'cos they use Dellorto's for pocket bikes.
Next experiment is to try fitting a Dellorto PHBG 19mm Carby to my engine!!
19mm might be too big but I got it very cheap (its a replica) and they do use them on mini bikes with sucess. | 
06-24-2008, 11:50 PM
|  | Master Bike Builder & Forum Sponsor | | Join Date: Dec 2007 Location: Duvall, WA PNW
Posts: 1,663
| | Re: Dellorto PHBG replacement Jet I was looking at the 19mm as well.....keep us posted.
I ALMOST ordered an 80,83 and 85 from DELLORTO Direct - but $10 for shipping - yikes....
Last edited by Pablo : 06-24-2008 at 11:53 PM.
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06-25-2008, 07:20 AM
| | Senior Motorized Bicycle Builder | | Join Date: Jun 2008 Location: Australia
Posts: 97
| | Re: Dellorto PHBG replacement Jet Well I can tell you that the Throttle cable fits but you have to remove the cable guide at the carby.
The carby slips OVER the manifold snugly which is an amazing coincidence unfortunately this doesn't work for long because liquid fuel quickly gathers at the 'Step' down to the smaller diameter intake tube so it runs rich as ****.
I did get it going tho briefly. These PHBG's have THREE jets! an idle circuit, main jet pre-mix circuit and a choke circuit. There is an idle mixture screw but no main jet mix screw cos it doesn't need one being a pin/clip design like the stock NT's
All I need is my custom 19mm manifold made up.
I am drooling in anticipation | 
06-25-2008, 07:22 AM
|  | Master Bike Builder & Forum Sponsor | | Join Date: Dec 2007 Location: Duvall, WA PNW
Posts: 1,663
| | Re: Dellorto PHBG replacement Jet Please post picts of the manifold when you rig it....you da man!!  | 
06-25-2008, 07:40 AM
| | Senior Motorized Bicycle Builder | | Join Date: Jun 2008 Location: Australia
Posts: 97
| | Re: Dellorto PHBG replacement Jet Will do for sure. My Dellorto Repllica cost me $40 AU! Hope it is good working order.
I've got an expansion chamber muffler coming soon too, I'm going to get the same guy to make me up a header pipe. really wanted to get the one from Easy Rider but postage to Australia... I'm looking at $200+
Being lazy I'll have to post some pics soon | | Thread Tools | | | | Display Modes | Linear Mode |
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