Thanks.
There are several differences between carbs, if i rember correctly 63 or 65 carb has a different internal volume. This again affects fuel economy and how the engine tunes. There is a lot more to the carbs than what meets the eye.

Thought so, thank you!!

Thanks for the info. So can i say both carburators are identical except for the neck section material? No different in tuning characteristic?

There is a .5mm internal difference between the two in the exit (bottom side) of the carb , not noticeable in the tuning , yes one of the carb bodies (063) is composite material all the way from the bottom to the slide barrel and one (069) is lined with metal and machined instead of molded .

Never fear its a non issue

If he were asking about a 63 and 65 I'd say you are correct but he was asking about a 63 and 69

Ya that ones a wee bit "different" Pauly

Then the Question:

Does the 65 use less fuel and how does it tune comared to 63 and 69? I have asked before but it was when Nova announced it. Now, maybe someone have experience with it :-)

The 65 in theory is supposed to use less fuel. I have one on my clockwork btt and on some track I've been able to run 12 minutes full to empty. I never tired the stock carb on it so I can't tell you if it would be just as good on milage or not. The top end needle usually ends up in a similar place as the stock carb but since the low speed is so much different it's tricky to get set from the beginning. It super buried in but that's normal because of the different look of the slide. The smaller restrictor you use like any carb it will be more sensitive to needle adjustments.

I often switch between 63 and 65 depending on track location. Since 65 is 7mm carb it uses less fuel to mix with air to get perfect mixture (63 is 9mm) Given the same track (45 seconds track) i can get 14 min with 65 compared to 12 min with 63. However, when i race at high altitude, its very difficult for me to get the tune right with 65. The room for error is very small. 63 is a lot more forgiving. 65 is smoother at the low end. And the low end needle with 65 is almost all the way in. Hope its useful. I havent tried 69 yet so i cant compare.

wow 14min with the 65 carb..... are you using 5.4/5.2 venturi or smaller one??
can't even get the tuning right for this carb maybe due to my hot wheather

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I always use 5.4 ventury. Im not saying its the best but when i first switched to BTTS, i started with 5.4 and 9901 pipe and stick with them. Never tried other combination. I find it 'easier' to tune when its closer to sea level with 65 But when i race on higher ground, i'd rather use 63. Anybody know anything about 69 carb?

Other than this new carb, does Novarossi have anything new they're coming out with in 2013?

I tried the 9901 with the 41021 in Australia and can't believe what a waste of money that pipe was. Very disappointed in the performance. Lost heaps of top end and bottom was ok. But only okay. I will order a 9886 or 9853 with a 41001 header and see how that goes, hope I'm not wasting more money on bad advise.


I usually run the 2096/41021 combo and it seems reasonably good. Want more over all grunt though.

Didnt you ask about EFRA legal pipes?

Neither of the two you mentioned are EFRA legal

Good luck to you

9853ss/41001 is a very good buggy torque setup bug not EFRA approved