okk then fair enough anyway the main reason i used the premium fuel was for fuel economy..Anyway so i decided to take off the air filter and have a look and what i found was what looks like a gasket been sucked in?? and also on full throttle the secondary jet is not letting in any fuel could this be the reason of why it is bogging down? ill add some photos of the gasket?

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bump...any ideas on what it could be??

How the hell the gasket do that?

I ran 98 when I ran petrol. Tuned for it and I always had issues with ulp and 95.

In theory they all have different flow properties and in.carby cars thus can.cause issues. Same but not as bad in efi cars. Injector spray etc.

Fix gasket check why secondaries not working, and retune.

in my experience this sort of thing is typical of weber carburettors, a full rebuilt and professionally tuned weber can only be expect to work well for 6 months before issues with gaskets, loose screws and jets, falling out of tune and cracked diaphragms.. had this many many times over the years

best option is the GX style SU's

Second Rc the 32/36 rattle apart easy :)

okk thanks for all the information i think im just going to take it to my mechanic and see what he says i still reckon it has something to do with the fuel but anyway hopefully he will know..

Thanks

Just abit of an update thought i would let you guys know i went to the mechanic that i take my ute to told him what was happening and showed him the gasket he reckons that its either a bad batch of fuel or because its premium fuel that therefore it its pretty much cleaning out all the gunk sitting in my tank and maybe blocked one of the jets of something as for the gasket he said its rare to suck in a gasket but reckons it did it because of the extreme backfiring its been doing which sucked it in. its booked in next Tuesday so he can have a better look.

Thanks

Up Hear in Qld A few Guys in a datsun club NEVER USE any fuel From Caltex
As do i Only Use BP 98. I would get around 280ks out of 30 liters
On a Stock A12. I recently started useing a octant boster with just 91.
on long drive,s that i have been doing i got almost 100ks more out of 30L
And the car runs better now

yehh well i wont be going back to that fuel station anymore might stick to BP from now on. Ahk yehh i have heard a few stories about that octane booster my mate has a AE71 corolla and uses it all the time he reckons its great..

I've never had problems with my twin downdraft Webers except when I had a blowthrough SC setup. With the drawthrough they have been working great. I've been dumping huge amounts of fuel into the cylinders and my plugs still come up nice and clean. Stock Webers have 40's for both primary and secondary jets. I have two carbs and I run 210's in the primarys and 60's in the secondarys. I have gased my car up at the airport a few times with 104 octane with little or no results. No problems with the carbs. It just cost to much to run. I just stick with the 92 octane. Oh and the chokes, I yanked those out. They just restrict airflow.