well have established that i have 1.5 twin sus on the a15 (thats what gx had as well i belive) but struggling to find out the jet size. should it be .90 or 1.0 thou size jets from factory?

reason being if its .90thou have plenty of mini guys that have parts on hand, if its 1 thou then have to either order needles from sydney or o/s if not available.

Any one have any idea as a strarting point what size jets i should be lookning at and needle size if possible.

stop fooling yourself mik

everyone hates these carbs cause they cant find someone (experienced mechanic) who can tune them right... now your asking for opinions on the net?

take it to rob!!!!!!!!!!!!!!!

Original GX engines used Hitachi Variable Venturi carbs. They look & work like SU's, but they are Hitachi's.

Sort of like fitting a Holly to your car & calling it a Rochester.

I, & several others I believe, have used the original GX induction for many years with great success, & if the performance of my 1200 GX engine is any guide, then I would swear by them as being the best all round street induction for our A series engines.

uhhhh, tuning su hitachis ain't rocket science mate

Quote:
speak for yourself mate
i love em, never had an issue with em, and never had to touch them once, after i had it running right.people always seem to be after these carby setups

vairiable venturi, vairiable main jet.. bit like a Rochester Quadrajet (another majorly underated carb, 780cfm, vairiable mains, air valves on the mechanical secondaries).. ha ha

it's all about supply and demand...

but don't tell everyone.. they will all want some..
you should get hold of an SU needle book, that is if they are SUs as Chris mentioned, and a dyno, once they are tuned, to suit your application, they will be great, same as any carb..

i am a big fan of them myself, i replaced the webers on my rally car with these and never looked back

im not fooling myself on anything. will take it to rob once i can get a day off during the week, which wont be till after August!

I was talking with my old mini guy and he was asking about what jet size etc. They are hitachis but apparently you can still you the same jets and needles from the su catalogs.

My mini guy can have a quick look on a saturday for me when i get the car back but Rob doesnt do weekends due to the rally stuff etc.

I tried lloking for a su book on the web but not much there for free.

looking so i can understand whats going on with them. I dont hate them, if i hated them would i have looked for so long for a set before getting these!

Im trying to build some knowledge about these things, apparently thats a crime now.