Things what DO work: ADA velocity stack/filter


Local time
6:38 PM
Sep 18, 2008
Silicon Valley, CA
I recently ordered a package-deal set of upgrades for my Tanaka 33cc. Since I'm still in the first-1K-miles break-in period recommended by GEBE, I'm holding off on the carb and exhaust upgrades for now. (Well, the carb hasn't arrived yet, and they sent the wrong manifold for the exhaust, but anyway...) The kit also included an ADA air filter, billet choke, and nice aluminum velocity stack.

I did take the time last night to pull off the stock air filter/choke unit and replace it with the aftermarket choke, v-stack, and filter. Since the kit didn't include new bolts, and the stock bolts were long enough, I reused the original fasteners (hex-head bolts, flat washer, lock washer). This led to a minor equipment failure on my ride to work today, and a couple of useful lessons:

(1) If you reuse stock carb/filter fasteners, replace the lock-washers with fresh ones. The OEM lock-washers (split-ring type) had flattened out and were not effective.

(2) A tiny touch of high-temp loc-tite on the carb bolts is a Very Good Idea

As you may have gathered, one of the bolts backed out 3-4 miles into my ride and caused the air filter/v-stack to come loose and swing away from the carb, and the carb itself to lose contact with the cylinder head resulting in loss of power. It's the latter that alerted me to the failure. I reassembled things by the roadside (my bike toolkit includes a neat little hex/screwdriver multitool) and was back on my way.

To make a long story short, was the v-stack/filter upgrade and subsequent worth it? In a word, DEFINITELY.

Speed at full throttle on level ground: +0.9 mph
Speed at full throttle downhill: +2.1 mph

I was quite surprised that the effect was that noticeable, because I've had lackluster experiences with intake upgrades on larger engines, but the bike computer doesn't lie. Performance at WOT is definitely improved with the ADA filter and billet v-stack/choke combo, even with the stock carb and exhaust. I've attached a picture which shows parts similar to the ones I installed and tested.




  • tanaka-ada-vstack-airfilter-choke.jpg
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New Member
Local time
8:38 PM
Sep 29, 2008
**** man i must say good find. but..where did you find these parts? and are their more? frankly, i'd like to go faster than 25 mph (i have an 80cc ebay kit from powerking(?))