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4 Stroke carbs

Posted: Tue May 11, 2010 9:47 am
by des
I have a 26mm Dellorto PHBH FS laying around the shed can this be used on a Lambretta or is it forever confined to the dark corner of my shed.

Re: 4 Stroke carbs

Posted: Tue May 11, 2010 10:29 am
by shocky
des wrote:I have a 26mm Dellorto PHBH FS laying around the shed can this be used on a Lambretta or is it forever confined to the dark corner of my shed.
yes it can be used mr knowledge has done a few it involes drifting the brass tube that the neddle goes through out and puting the correct spray tube in i think they cost around £10 other jets neddles and slide may be needed as well to make it work correctly so factor that in and order if needed when u get the spray tube or ask on here there plenty of people with spares ohh and good luck

Re: 4 Stroke carbs

Posted: Tue May 11, 2010 3:04 pm
by des
Image

Cheers Shocky, is this the part you part you mean.

Before i order what jets etc would you recommend if i wanted to run it on a SR186 kit with a Suzuki piston

Re: 4 Stroke carbs

Posted: Tue May 11, 2010 5:23 pm
by shocky
des wrote:Image

Cheers Shocky, is this the part you part you mean.

Before i order what jets etc would you recommend if i wanted to run it on a SR186 kit with a Suzuki piston
yes thats the par,t i cant make any recommendations as every one is different but im sure there someone on here running something similar altho the 26 is a carb thats not that popular the 25 and 28 are some struggle to set the 26 up i dont know why as ive never used one maybe ring a few dealers/tuners first

Re: 4 Stroke carbs

Posted: Tue May 11, 2010 5:29 pm
by shocky

Re: 4 Stroke carbs

Posted: Tue May 11, 2010 7:59 pm
by oldbiker
You my find that you need to change quite a few bits. slide and needle (most likely) and I have a feeling that most carbs have different weight floats for 2 + 4 stroke engines but 4 stroke carbs can be set up for 2 stroke use.

I find nrp carbs to be about one of the most helpfull places for carb parts (that`s all they sell) They are on the net but the web site is not complete, they do reply to emails and the service is quick I have used them for a couple of years.

http://www.nrp-carbs.co.uk/

Re: 4 Stroke carbs

Posted: Tue May 11, 2010 9:47 pm
by carlos fandango
Posted this earlier


You can use them no problems. But you need to do a few mods. first.

The spray tube/atomiser bush ( the brass part that protudes into the carb bore/venturi.) if it does not protude then its a four stroke and needs changing.
Its a push fit and costs about £9 [url]http://www.dellorto.co.uk/merchandise/p ... nID=24/url]

Then carb has two small holes at about 6 o`clock one the front of the carb. the right hand one will be blocked with a brass plug (on a four stroke), this needs drilling out. the hole should go all the way through to the spray tube.

Obviously the jets and needle will need changing as appropriate. it also may have an extra jet this is a power jet and can be blanked of with a suitable screw/bolt.

Ive done these mods. recently on a 26mm and works fine. i can post pics if you want?
Russ

Re: 4 Stroke carbs

Posted: Wed May 12, 2010 8:58 am
by des
carlos fandango wrote:Posted this earlier


You can use them no problems. But you need to do a few mods. first.

The spray tube/atomiser bush ( the brass part that protudes into the carb bore/venturi.) if it does not protude then its a four stroke and needs changing.
Its a push fit and costs about £9 [url]http://www.dellorto.co.uk/merchandise/p ... nID=24/url]

Then carb has two small holes at about 6 o`clock one the front of the carb. the right hand one will be blocked with a brass plug (on a four stroke), this needs drilling out. the hole should go all the way through to the spray tube.

Obviously the jets and needle will need changing as appropriate. it also may have an extra jet this is a power jet and can be blanked of with a suitable screw/bolt.

Ive done these mods. recently on a 26mm and works fine. i can post pics if you want?
Russ
If you could post some pic`s that would be great cheers Russ.

Re: 4 Stroke carbs

Posted: Wed May 12, 2010 10:25 pm
by carlos fandango
des wrote:
carlos fandango wrote:Posted this earlier


You can use them no problems. But you need to do a few mods. first.

The spray tube/atomiser bush ( the brass part that protudes into the carb bore/venturi.) if it does not protude then its a four stroke and needs changing.
Its a push fit and costs about £9 [url]http://www.dellorto.co.uk/merchandise/p ... nID=24/url]

Then carb has two small holes at about 6 o`clock one the front of the carb. the right hand one will be blocked with a brass plug (on a four stroke), this needs drilling out. the hole should go all the way through to the spray tube.

Obviously the jets and needle will need changing as appropriate. it also may have an extra jet this is a power jet and can be blanked of with a suitable screw/bolt.

Ive done these mods. recently on a 26mm and works fine. i can post pics if you want?
Russ
If you could post some pic`s that would be great cheers Russ.
Here you go..... the first pic is the 4 stroke 26mm (spray tube already fitted) the hole at 6 oclock is the one which has a brass plug
Image

This pic shows a 30mm two stroke with the clear hole ( not very goo pic.)Image
Obviously make sure you clear any swarf from the carb :shock:

Re: 4 Stroke carbs

Posted: Mon Jul 29, 2019 9:32 am
by Norrie Bodge
Old thread I kno ?
Just acquired one of these carbs, anyone know what motorcycle are fitted with these?

Cheers