Hi All,

 

I picked a pair of these up a little while ago and have been meaning to get around to paying them the attention the require. They had been sitting for a few years, but the butterfly's still move in a nice smooth motion and with a decent clean they should come up nice. I am thinking about buying a DHLA40 rebuild kit, something like this...

 

Click Here

 

I was wondering if anyone else has done a similar service to their Dellorto's or equivalent, and how they found the experience. Would this be all that is required for a fully serviced carburettor? I need to get the two carbs re-jetted to suit my motor (hopefully a 5K to replace the 3K in my 1972 Ke20), should this be done first, or can it be achieved after the new kit?

 

Also, whats the best thing to clean these beasts with? I did spend around 2 hours initially with a toothbrush and a tin full of petrol giving them a mild clean with some good results, but If someone can suggest something better, I am all ears.

 

Any help would be great. This will be a massive learning curve for me, with my aptitude being more electronic/electrical.

Edited January 9, 200818 yr by bboy_h

Gday mate,

 

I'm going through the same thoughts as you are at the moment. I've rebuilt a couple of OEM carbs in the past, and I've been pulling my DHLA's apart and taking a look inside them recently.

 

If money is no issue, I would suggest you just buy the kit and just do it, especially if you don't know the carb history. Most of the bits will be self explanatory as you take them apart.

 

As for rejetting, this kit wont do that for you. Most likely you'll need to buy jets etc seperately. Check out Gem Parts on ebay, they have some jet sizes.

 

Before you buy though, have a good read through this:

 

Dellorto Jet Sizing

 

If you follow that through, you will have all the numbers you need to chheck against what you already have. Its a simple matter of removing the plastic cover on the top of the carb and unscrewing the little brass screws you see. These are the main and idle jet/emulsion tube asseblies. Have a look and you will see numbers, cross check those against the article above.

 

Also, peer down the inlet side, and you should see a number cast into the face of the venturi, something like 28-38, thats your venturi size.

 

Once you have all those numbers in the ballpark, you should be ready to put them on a car and start tuning as per that article.

 

Also, I have another link that explains the operation and guts of the carb really well, i just have to dig it up. Its a must read for anyone trying to understand how and what these carbs do, so I will post it up tonight when I find it.

 

As for cleaning, probably petrol and elbow grease. A bit of Autosol metal polish once clean will polish it up too probably.

 

Cheers.

 

tom.

Guys these carbs are easy to service, a standard carby would be harder,

 

just make sure you put everything back in the right place.

Carby cleaner is the stuff you should clean them with.

 

the carby kit only comes with gaskets,seals,diaphrams, and needle and seat. NO jets!!!

it should also have a diagram with an exploded view of the carby.

 

Don't remove the throttle plates as you can damage these easily.

there is also bearings on the throttle shafts, it's good idea to put some grease into these, just pop off the grease seal to get to the bearing.

 

Don't forget to set the float level as well, Google it. it's measured from the base to the bottom of the float with the base upside down, the instructions may even have it.

 

hope that's helpful.

ok heres that other link

 

definitely read both those pages, and you will gain a good understanding of how they work (which then equates to knowing how to work on them!)

 

even better, read it as you pull them apart.

 

Reading Time!

 

Good luck

nice link!!! :drgrim:

yeh its killer isnt it.

 

took me quite some digging to find that.

Top site, do you know of some good ones on SU's?

I have been through a couple in the past, when I was looking to use them:

 

Su Carb operating principles

 

Nice cross section diagram. Always a good thing.

 

This has some good stuff as well, but not heaps More on SUs

 

There is a good article on tuning and balancing them as well, I can't find it at the moment. Will update.

Top Stuff.

 

Thanks for that.