How to rebuild a Dellorto carburettor

A Dellorto PHF 32A carburettor rebuilt from scratch. These carbs were used on many late 1970, early 1980 bikes.
This is off a racing Laverda Montjuic and there is no accelerator pump used (it runs 175 jets). I missed out setting of the float height (18mm).

[@hughjones6933]

Alder just sorted the Dellorto PHF 32 on my 3C Your Video is fantastic, a great help for me CHEERS your a TOP Bloke

[@aldermarsh6776]

Glad it was of help Hugh, and great to see someone keeping the 3Cs alive !

[@dazmurphy2017]

Thanks for the informative vid. I have a pair of a Montjuic that I intend to fit to a BMW R65, however I need intake spigots for the rubber mounts. Are the ones in the picture for a Laverda, and if not, where did you get them?

[@aldermarsh6776]

Hi Daz. The spigots were specially made for my race bike as the standard spigots can cause the carb to foul the frame tubes.

[@richardyoumans223]

Hi Alder The top setting on the needle. Does that weaken the mixture. Thanks.

[@aldermarsh6776]

If you move the clip from the middle to the top of the needle, it causes it to sit further into the jet, which reduces the amount of fuel coming into the carb - hence weakening the mixture.

[@Attack2001]

Hi Alder, Your video is extremely timely for me right now. We use phf singles on a pair of race karts. I've only recently noticed the pump biase and now you've shown me the fix. Excellent. Can I ask please are the blanking plates bought or made? Is it just flat plate and what do I do with the two projecting holes at ether side. This is obviously why we missed our dyno session this week. Looking forward to hearing from you.

[@aldermarsh6776]

Hi EvoToad, The blanking plates were made up from a piece of flat ally plate - very simple. The two projecting holes you mention feed into the side of the intake venturi so you don't need to do anything with them, however I had a blanking screw made up just to keep the port threads clean (see video at 13:10). I've just had the bike on the dyno and have kept the 175 jets, but have taken the pilot screws out four turns. Good luck !!

[@Attack2001]

Alder Marsh Thanks Alder we will be making these today as we have two karts. This problem was top of my list as of last week so your video help was perfectly timed. Good luck with your racing as well. Regards Roger.

[@swarduk]

Hi Alder, do you offer a service to clean and setup carbs? I’ve got issues with my Pantah 650

[@aldermarsh6776]

Hi Steven. Sorry, I decided not to offer this service commercially. I can strongly recommend Ducati Paddy though.

[@papastanley]

Hi Alder - at the end you said you put the top in after you bolt the carb body back onto the bike. Really? I just dismantled and cleaned 3 of these off my Laverda 3CL, left two top assemblies together but took out the needle on the third to check which type I had. I had a hell of a time getting that spring and needle clip setup back together on the bench, let alone if it was on the bike. Or did I miss something? Seems pretty tricky to me, what’s your method?

[@aldermarsh6776]

Hi Papa. The key to getting the slide/spring/needle all put together easily is all to do with keeping the spring compressed. Make sure the throttle twist grip is fully closed (I use a rubber band to keep it from moving). Put the needle with fitted clip into the slide making sure the gap in the clip is where the cable end slot is. put the spring over the end of the throttle cable end, and compress the spring as far as you can, then find a way to hold it in this position with one hand. At this point you should have a large length of cable protruding from the underside of the carb cap and (keeping the slide vertical) slip the blob of the end of the cable through the hole in the slide and pull it sideways into position. Then you can release the spring. I'll make up a video clip to show you. Good luck !! G

[@aldermarsh6776]

I've put up a new video to show you how I did it on my Montjuic. Hope it helps!

[@trey8367]

😂