Ported CAG carburetor with pictures!

[Crash Dummy]

There is three big problems with a Dellorto gti89
They cost $60 for the kit
They often fracture around the neck where they join onto the manifold
They don't fit on my F2 CAG

And so far in my experience I haven't tried a walbro carb that will do the job either.

[gtti89]

we had a guy who raced here in Bundaberg (now races in gladstone) with an F2 with a 14/14 fitted, i dont think he ran a pod style filter (from memory it was material like fly screen) and it fitted with room to spare , however i dont know if he shifted the engine forward

zocchi manifold (rubberised one) will solve the cracking problem
i raced all last year with a 14/14 and zocchi manifold and had no problems

[andrewbower2]

$85 for the rubber manifold

[Crash Dummy]

When a new CAG can be bought for as low as $150 I probably wouldn't be able to justify spending $85 on a manifold then $40 on a carburettor. It seems kind of silly IMO if your capable of going DIY and getting 98% of the result or more.

But different strokes for different folks. I'm the kind of guy where if I can do something myself and achieve a good result from it I'll go for it. Especially now that haven't got a money tree growing in my yard since I moved house.

[gtti89]

Originally Posted by Crash Dummy

. Especially now that haven't got a money tree growing in my yard since I moved house.

i would lend you mine but the wife has stripped it bare

with my old bike i guess racing in a competitive class, i needed as much hp as i could grab

[Bighomedog11]

I got a question before i do mine. I am wonderin were it says Carb throat. Dont grind back there only grind threw the intake and stop were it says Carb throat? And i also want to know do i just make the inside and outside as big as the choke plate? Or is that too big? Because i dont wont to make it too big and it not work right. please help because i really want to do this just worried i might mess up

[Crash Dummy]

It is not advisable to go larger then the choke plate. Although it won't hurt engine performance it could make starting the engine difficult.
The taper should stop before the sliding piston.
The way this works is you can virtually increase the size of the throat so long as you don't go so large that you end up grinding the walls that the sliding piston travels along because this provides a seal. If you go past that you end up having air bypass the slide and won't be metered. The other limit is that if you do grind out too much material you do run the risk of breaking through into the float chamber.

Bighomedog11 the key is to just take it easy. GO SLOW. Your looking for a nice smooth gradual taper. The grind doesn't have to be wild. Your just looking to improve the flow into the carburettor and if you choose the grind the throat out then your aiming to increase the overall volume that may pass.

Now to all who have read this article. Thank you.

[*79*]

whats the best performance carb

[gtti89]

for a worked cag - 15mm genuine dellorto

watercooled - 18 or 19mm genuine dellorto

these do require brains to set them up, and that scares a lot of people

[mac90]

i have not tried the genuine dellorto,s

i used a genuine wt603 walbro & they work really well
they also need a bit of a fiddle to get the mixtures set up but not all that hard

but i would buy genuine of either the reps are just that a replica or cheap copy of the real deal