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Post by milly on Sept 16, 2017 18:54:37 GMT -5
I am putting on a Naraku 72cc bbk on a scooter
I did a 80cc one and fitted a A9 camshaft as recommend.
I have read somewhere that an A9 camshaft is not necessary on the smaller bbk.
Is this correct please
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Post by greginisn on Sept 16, 2017 19:56:50 GMT -5
Hi,
From what I've read people seem generally very pleased with the A9 and the 72cc kit. Although some say it wasn't worth it I have to wonder if they got the cam timng right. You know, maybe 1 tooth off? I'm planning todo a 72cc kit too but will ride it for a bit before I go for the A9 cam. The reasoning is that doing both together I'd never know for sure how much the cam actually helped.
My scoot is quite new and some people have also written that the A9 cam and the cams in recent TaoTaos have the same grind. I don't know, it could happen, but I am dubious.
Good luck, Greg
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Post by cagiva4ever on Sept 18, 2017 8:31:50 GMT -5
maybe this has some usable input for "milly" , as a A9 cam related : regarding user feedbacks, why they maybe varie: if A9 cam timing has been wrong, maybe factory hasnt Aligned the Cam sprocket right on the CAM..as doesnt A9 have a basic Shrink fit between cam/sprocket ? and not a w-d-key. iirc if cam/valve timing has been of by 1~2t, then engine hasnt worked properly at all, meaning opposite to smooth and linear and clean rev'ving. i say that from perspective that other A9 user feedbacks have been all good/great on 139qmb 50~80cc. ^^ that all is what ive read over the years, as i do not have my own A9 cam yet, which leads me now to my purpose here: is there Fake/ -or false advertised A9 cam's on eBay for Gy6 139qmb 50-100cc ? as some dont have "Drilled" Cam sprocket as the ones marked AT-A9. its difficult to filter wrong ones as ive not yet found a single seller who has posted Cam specs. im trying to source a genuine A9 cam from eBay for my 50cc 139qmb (later 72cc). eBay is my only option as i do not have/own Credit card for buying from Aliexpress , Amazon etc. i only have Paypal. in European so its not economical to source/buy from states. or economical to even buy from my own Country where qty:1 A9 would cost 3~5x the price of common eBay price for qty:1. at ebay pricing varies much, hence trying to choose the correct/best one. issues such as "XS" brand bearings Vs. "NTN china" etc issues. ive been browsing web 20+hours during past weeks trying to find a good seller/source, with resonable price. any help ?afaik none seller at Aliexpress takes Paypal ? if i choose good, i could buy qty:2~3 for a price of qty:1 vs from wrong seller.. From this forum ive tryed and tryed to Google target search A9 specs etc info, and so far ive found only this, data wise it looks good as a comparison : 49ccscoot.proboards.com/thread/11920/139qmb-cams-cheap-spec-less?page=1direct copy paste from linked topic: Apr 21, 2015
I found this sitting around, and I'm pretty sure it's for my 139qmb A9 camshafts.
"
A9 Cam specs:
Intake lobe widest point: 25.78
Exhaust widest point: 25.67
Lift: 5.86
Lobe Separation Angle: 119 degrees
Stock Cam specs:
Intake lobe widest point: 24.48
Exhaust widest point: 24.52
Lift: 5.02
Lobe Separation Angle: 116 degrees
The A9 cam has 3 degrees more separation, when combined with the wider lobe and higher lift, forces the valves to stay open longer- which allows more time for larger intake and exhaust volumes. This is the reason they rev higher and have more power output than the Stock cam."
Scooters To GO
Affordable Sales, Service, and Performance
744 36th St SW
Wyoming, MI 49509
(877)569-5691
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Post by greginisn on Sept 22, 2017 22:00:47 GMT -5
When I look at the the numeric comparisons I have to wonder how the untrained eye could tell a stock cam from an A9 cam. No cheating and looking at the sprockets allowed.
Greg
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Post by cagiva4ever on Sept 23, 2017 14:35:48 GMT -5
thats the issue problem, as it isnt obvious huge difference by naked eye. hence trying to figure out if ebay has at the moment fake/false advertised cam's for sale.
hence i was asking if them genuine A9's have drilled sprocket....
i have no answers yet. help welcome.
anybody happen to have Naraku 139qmb cam measures, for Touring/R versions ?
NK500.02T
NK500.02R
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Post by cagiva4ever on Sept 25, 2017 4:22:44 GMT -5
ive done some Native interwievs, user feedback on my own Country. apparently some 139qmb Performance cam's do exist are made with plain non-drilled cam sprocket. These cam's are "no-name, no brand" Cam's.
This deffo makes it hard to spot the real performance Cam out of eBay/wish etc sales places. IF buyin cheap not paying the ~3x price Vs Branded one.
i got some sample photos also now, from my Natives who have these "no name" Cam's and have measured and used-use them.
basically only Duration varies (no name Vs stock 139qmb cam). lift and overlap is same. But as its Chinese thingy, some other "no name" cam's might have tiny bit more Lift.
im personally only after little more Torq that the A9 cam will give to a 50cc/72cc with 50cc head.
and im trying to avoid buying Pricy branded A9, if i can find "no name" that is ~3x cheaper per qty:1. idd buy 3x.
if somebody spots a "no name" A9 copycat cam that has non-drilled sprocket, on wish.com Banggood or eBay, Paypal place, please let me know. or if someone knows a seller name/id who has sold them on mentioned pages recently...
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Post by greginisn on Sept 25, 2017 19:58:56 GMT -5
OOPS! Greg  I forgot who had posted this. Holy cats Milly that's a serious price kick up from USA price. But it may be your only assurance of getting what you really want. That's a bummer! From Amazon and Amazon UK. Greg |
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Post by golfmech on Sept 26, 2017 16:19:28 GMT -5
I can tell you with all honesty you can visually see the difference between a stock cam and an A9 I wish I still had them out so I could show you but take my word for it a true A9 has visually thicker lobes meaning longer duration. Right now the a9 cam on eBay for $20 with free shipping is a genuine A9 it's the one with multiple holes in the cam gear. I can't testify as to the performance gain because I did the bbk at the same time but you definitely can see the difference in the lobes.
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Post by cagiva4ever on Sept 26, 2017 18:02:42 GMT -5
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Post by golfmech on Sept 27, 2017 10:37:48 GMT -5
Not exactly sure what your asking but the lobes on the cam in your second picture look identical to the A9. I did see two cams listed as A9's but one had a stock looking can gear and the other had the one with multiple holes in the gear. I went with the one with multiple holes in the can gear under the theory that at least if I'm getting ripped off something will be different lol. I was pleasantly surprised that when side by side I could tell that the A9 I bought had bigger lobes.
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Post by AtariGuy on Oct 2, 2017 12:52:59 GMT -5
at one point during brents project tao-tao he did do some degree measures of an a9 and the stock cam or something of that sort. if i can find it quick, i'll link it in a moment
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Post by cagiva4ever on Oct 2, 2017 13:28:08 GMT -5
that would be nice, it would add up into Collective info. at least for later winter reading and learning.
as ive read forum posts for hours, and its all mostly useless not in depth or nothing at all, just "bolt on style".
i think i have finally found a tru "no name no brand" A9 clone seller. have to wait many weeks for them to arrive once purchase finished. i shall then take make a 1:1 drawing from Lobes, stock cam Vs "no name". that is still not much but something for a Collective info.
for the "Naraku Touring" etc i posted photos earlyer, ih ave valve lift mm's etc, just that thye are basically written in Jibberish speed writing By author. ill try and post them later once i re-read them and try and translate them into english..
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Post by cagiva4ever on Oct 14, 2017 13:17:33 GMT -5
while browsing sellers-sales, stumbled onto this a-hole seller at States www.ebay.com/itm/Camshaft-GY6-50-139QMB-Scooter-Moped-US-Seller-/151840919991?hash=item235a6c91b7:g:TQsAAOSwKIpWFK5H&vxp=mtrtotally Miss leading buyers, by using A9 photo on "top cover/case" and stock cam photo on 3rd, as surprise surprise the sales is for Stock cam. 2 byers on Count..... then there are those sellers who sell stock 139qmb cam and have also 125cc 150cc A9 cam on same photo portfolio, but no mention about double item/choose right or anyhing. only selling stock cam. anyway, i have now found my suplyer(s) good1. found out the manufact product code for identification etc details. ordered a sample from 1 source and more from 2nd source next week. having both C3 expansion clearence and P6 marked ones. as its long wait, its already Xmas almoust when i recive last patch... and it was only last week when i accidently found "90GTVert"s NCY perf cam topic. when i recive my 2nd samples i see if their NCY clones or re-named/buyer re-tailored NCY perf cam's. |
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Post by savage75 on Oct 12, 2023 12:26:22 GMT -5
Anyone know if it's better to use the 64mm valves on a stroker 52.4 millimeter piston 87.6cc without stroker 94.9cc with oversized valves meaning more surface area greater mass or 69mm valves smaller surface area less mass but more travel? I guess it depends on where you want your power low middle range or top end?
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Post by br4inl3ss on Oct 15, 2023 8:29:34 GMT -5
valve lenghts have nothing to do with bore or performance. its only a design, dependent on rocker.
64mm / 69mm valve is not the size of the valve but the lenght of it.
so absolutly no gains there. you either go with 64 and matching 64 rocker, or 69 valve with matching 69 rocker.
A9 cam shaft is not necessary, but really wake them up. its HUGE. not as huge as honda kids and thier vtec eggeration, but huge. it even wake up the stock 50cc so imagine a bbk.
i didnt have the chance to get there with mine but friends around did and i was able to test before and after, on all 50 72 81 and 88cc bbk. they all had incredible gains. but the bigger the bbk, the bigger the gain was, relatively. someone i know is running a naraku 90cc kit with A9 cam, but i didnt test it. he moved far away. but he said the stock vs A9 cam on his 90cc was similar to the difference between 50 and 72cc. maybe a little bit less but not much.
if you get a fake one ( and there is alot ), the gains is ZERO. its stock cam with A9 label.
if they dont give the lobe and other specs, skip.
stock :
intake lobe 25.7mm
exhaust lobe 25.5mm
3 different A9 friends measured :
intake lobe 26.5mm
exhaust love 26.35
ive read some A9 have different measurment but whatever those are from reliable source.
the only gain you can have with valve is finding a big valve head. ots way over price, and difficult to find.
a friend of mine is running a true 88cc ( 52mm ) with 52mm head, but he got the head machined to run Honda bigger and shortened valves ( no idea where they come from... i guess its from 80cc elite or 3wheller or dirt bike i dont know ). the head with valves and machining cost him half the price of the ncy big valve head.
other option is finding the impossible aka the scammer Rolling Wrench 4 valve head. but warning this guy is a huge scammer. he pay carb kit between 25 to 35 for EVERYHING even intake on aliexpress, put the intake on it, remove carb brand marking, and sells for 175 + overcharged shipping ( he use the same marketing tricks as ebay : increase shipping price for profit, but unliek ebay he doesnt drop item price ). thats not big profit, thats SCAM at this point.
and dont try to get any after sale help he will try sell you his useless videos. even if you received a defective product.
reddit is full of proof of his bullshit.
he know his shit, but on the business side, just stay away.
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