Quote:
Originally Posted by blueboy5000
38mm is the standard size of a 50cc gy6 carb filter-side. That carb is a basic 19mm standard 50cc carb.
The standard size carb for the 150cc is a 24mm with a 42mm filter-side(inlet).
50mm is 74.5cc, so it's an 80cc, not a 100cc.
Now about carbs in general:
Bigger NOT better. With carbs, it's about stoichiometrics, which is optimizing the air to fuel ratio, it's not about simply throwing more gas at it. So a 150 carb is pretty much useless to a 139.
You probably have a larger main jet in your current carb, or it would be dangerously lean, or most likely, not run at all with the stock main jet.
The speeds you indicate are about the maximum for your cc's w significant cvt mods.
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If you read my OP, you would see that I know a 50mm BBK is not a 100cc (just what they CALL it)
lol...
Nonetheless, I have more info on the bike now. it does about 45mph on flats, GPS verified, with my 190lb a$s on it! I would like to get some more speed out of it, take off is GREAT but top end really struggles, IMO. I think the previous owner PROBABLY put lighter rollers in the stock Variator, with all of the other stock CVT stuff.
That said, I don't think my carb is stock, but what do I know? I'm just a "Junior Member"! Haha... I do have a stock Tao Tao carb sitting right here, it looks nothing like it and you can't even adjust the low jet setting - without me dremeling/filing a grove in it for a flathead! Which I've obviously already done. Anyways, it HAS to be upjetted, whether stock or not. It smells SUPER rich when being revved, after its warmed up, in my garage. Even get a little smoke, but I REALLY can't tell if it's black or blue. :mad: It doesn't smell like oil WHATSOEVER though and DOES smell rich, like I said. So I believe it's unburnt fuel! My oil level hasn't changed A LICK since buying it and it's still nice and golden, no blackness whatsoever, which to me is a trip. I've put AT LEAST 100+miles on it, since I've had it and the oil is flawless. I love THAT part!
I admit, I'm being lazy. I Still haven't checked the jets, I will very soon, when I put on a metal intake mani. THAT is another reason I don't think it's the stock carb, as it has a different intake elbow than stock! I think that part is pretty well tuned for the low end, nonetheless. I think the main jet could be leaned out a little more AND/OR have this performance exhaust I have sitting here slapped on (that would lean it out probably ABOUT "perfect") It's actually a bigger pipe w/ a 4 Stroke 80cc Dirtbike Muffler. I will be ordering a jet tuning kit (for the main) here very soon. I REALLY need to check the spark plug and do the 'ol site test, see if it looks as if it's rich or lean. I'm pretty positive it is going to be wet and black though! But, when I get the energy, it'll be pulled. Probably once I get all these "tuning parts"! I pulled the needle to see if it was adjustable, in order to maybe lean it out up top. Well, guess what?! It wasn't adjustable and someone had put a washer on the needle in order to get more fuel, from the main jet, at WOT. I've since removed that. (After removing it, the bike went from 43mph flats to 45mph flats). I also tuned the low jet on the carb that's on there, it idles and responds MUCH better, which I didn't even think was POSSIBLE! Lol! BUT THE LOW JET ADJUSTMENT ALONE WAS NOT STRICTLY THE REASON I PICKED UP LOW END....
I went as far as to pull my "Magneto Pick-up" off and used a dremel to "cut" into the bolt holes ON THE PICKUP "MOUNT"! I just dremeled out the RIGHT SIDE of the bolt holes in order to MOVE the pickup a little to the left (advancing timing).
I take no "credit" on coming up with this, but on YouTube of "Project Tao Tao", the guy does it and it actually works!! Doesn't everyone love "free mods"?! He had clear indication of exactly how much timing advanced was occurring at various speeds. It PROVED to work correctly and actually BETTER than any "performance CDI" he had! Amazing, I'll save my money!!! I checked my timing before and after, it only advanced it a tid bit! Enough to make a DRAMATIC difference (with the tuning of the pilot jet as well) on take off though!!!
Man, this thing FLIES to about 30ish and THEN really starts slowing up all the way to its top end. I would like some opinions here, but this is what I plan to do:
- Get all aftermarket CVT stuff, including a Kevlar Belt and a "Roller Tuning Kit"
- Get a "Main Jet Tuning Kit"
- Install aftermarket exhaust and muffler
- Possible valve lapping, but DEFINITELY ADJUSTMENT! (What's the best valve clearance for this 50mm BBK?)
If I can get this thing to do 50MPH, SAFELY, with me on it... I would be completely happy and I would begin on lowering, building a custom stretch kit, hardtail, LED lights, paint, New seat, etc etc... I plan to keep this bike "forever", as a backup for all of my vehicles. I WISH I would've never gotten rid of my Metro!!!
WHAT DO YALL THINK?!
(PS: Can I use ANYTHING off my Znen 150cc GY6 on this smaller Tao Tao 50cc GY6? Rollers? Variator? Any of that stuff an "upgrade" for the BBK TAO?