would explain my highway fuel consumption lol.

look forward to the tune tomorrow.

but with the thinner oil & the play it's running alot better.

Nah, the damper oil only plays a part when you stick your boot into it. It's the SU equivalent of an accelerator pump on lesser carbies At constant throttle position, the needle profile dictates the fuel flow.

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Simon

The adventures of an owner builder in the Tallarook Ranges

yeh i played with the mixture a bit & tried to lean it off.

but honestly i'm not a engine tuner so would rather pay to have it tuned & driving right.

but im surprised how much the oil made a difference.

idle as well the revs slowly died & i think the pot was having trouble moving up & down.

Yeah the dashpot oil changes the response of the engine when you expect a response -- i.e., when you put your foot down. It's easy to give more credit to that tweak than it's due.. if your needle is wrong, you'll still end up with the wrong mixture at some / all points throughout the rev range regardless of throttle position or idle-mix setting.

That said, it is satisfying when you change the dashpot oil and it goes that much harder, it's tempting to call it fixed



You'd be surprised how much better it'll go when you just take the carb apart and clean it

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Simon

The adventures of an owner builder in the Tallarook Ranges

Nick

Autobarn sell proper SU oil for $10.

Also my HS6 was a pain till it had the top off and was given a clean with carby cleaner spray. Made a big difference once cleaned. The oil was one part, cleaning all the cr@p off was the other. Once that is done I guess you can look closer at needles etc.

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Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

thanks Ls i will buy some tomorrow.

yes they are rebuilt twin su's.

just needs a good going over & that will be done tomorrow.

Interestingly, the workshop manual (incorrectly) says to use Engine Oil, which is actually OK for most normal driving. The genuine SU oil is straight 20 weight.

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Hey how did this change into a discussion about dashpot oils.

I've tried everything apart from the proper SU Dashpot oil. The best result I've had is from Shell Helix HX3 Multigrade 20-50. I've tried two stroke, mineral and synthetic, auto trans fluid (maybe it depends on the brand because I know alot of people on here use it and it works for them), three different weights of Motul Synthetic fork oil and a couple of other things, nothing worked I still got bad throttle response and inconsistent running. Next time I'm near an auto store I'll get some dashpot oil and give it a go.