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Post by prodigit on Apr 4, 2013 21:49:01 GMT -5
I have a TaoTao ATM50, gets just under 100MPG, and it's not lean nor rich. The spark plug looks just like new; if anything the tip looks a bit black, but the rest has no specific color to it (not white, not black, perhaps a tiny bit of light tanned skin tone caramel).
From the charts, they tell me, that my scoot is running just perfect as it is.
I'm planning on putting a BBK on it, without changing the jets or carburetor. I want 'a bit' (not a lot) more power, eventhough I'd be running lean.
Would I be able to do this?
I know many would give the advise to change the jets, but what if I just install the BBK head, and run lean?
Is the 22 extra cc's going to make a lot of difference to the fuel mixture?
I plan on running it lean, I only need a tiny bit more torque for a bit faster acceleration.
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Sophomore Rider
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Post by CopperDeer on Apr 4, 2013 22:20:14 GMT -5
I would restrict the intake a tad. I think it's asking for trouble to run it that lean. Higher octane helps that condition in my opinion but only so much. On an air-cooled bike I just wouldn't risk it. My Honda Civic Hybrid had a lean-burn mode the ECM could engage at low throttle cruising on the highway and stretch the A/F as lean as 22:1!!! But that is under very precise EFI mgmt conditions and sequential ignition (two spark plugs per cylinder). If it's MPGs youre after, I think a BBK with somewhat restricted flow might be that sweet spot you've been looking for.
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Post by skuttadawg on Apr 4, 2013 22:21:54 GMT -5
It will burn up unless you upjet . Larger displacement or exhaust or airfilter change will result in more and need more fuel to be balanced . The stock carbs are often sealed so a carb would be a good idea since they are as low as 30 for a stock size and MillSC has had lots of testing and good results with a larger carb and the 50 and 52mm BBKs , so I would listen to his advice . Since yours runs good I would enjoy it until it fizzled as that is a better excuse to take it all apart . I would replace the rollers with Dr Pulley sliders as you may wantto weigh your weights BEFORE ordering any . Mine cam with 8 gram and I switched to 5 grams which improved take off and uphill with the same top speed just higher RPMS . You may opt for heavier than 5 for MPG . Scrappys or Hoca are decent kits as I would avoid being another Ebay junk horror story victim with generic junk . I was impressed with Air Sals 50mm BBK I had on mine with stock carb ,upjetting , airbox and stock exhaust along with the 40mm head enviromoto.ecrater.com/p/9805082/airsal-50mm-aluminum-big-bore |
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Post by skuttadawg on Apr 4, 2013 22:29:30 GMT -5
This happened to a buddies GY6 when he was drinking and broke the muffler off . He rode it for 2 or 3 months without upjetting the barb or replacing the muffler and boom the exhaust valve broke and ate up the piston . I would rather you tell about riding than pushing so upjet it . A jet kit is a great investmen tin order to have many sizes to test and have handy for future mods like a Uni or exhaust upgrade . Here is a kit enviromoto.ecrater.com/p/4129835/naraku-main-jet-set-gy6-50Attachments:
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Post by prodigit on Apr 4, 2013 23:39:41 GMT -5
Ok, so I could go the way of changing the rollers.
Indeed, the engine revs to (hard to say without tach) ~7k RPM, when going 20MPH, and then slowly decreases to ~5k RPM when going 25MPH.
From 25MPH onward, the CVT is maximized, and the engine RPM's climb to max speed.
It's a very balanced setup, where acceleration at 25MPH is VERY slow.
On a windy day, the wind could stop the scoot entirely from going over 25MPH.
Rollers/sliders may be a better solution, I'll look into that!
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Post by JR on Apr 5, 2013 0:01:11 GMT -5
Your weights are a good starting point.
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Post by skuttadawg on Apr 5, 2013 0:16:42 GMT -5
We all want our scooters to go faster and most only think of engine upgrades where CVT tuning can make improvements with diff weights or springs and not cost that much nor as complex as engine rebuilding
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Post by prodigit on Apr 5, 2013 0:22:14 GMT -5
I should have thought of that before.
Anywhere where you can recommend some cheap, but good, sliders?
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Post by skuttadawg on Apr 5, 2013 0:24:21 GMT -5
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Post by prodigit on Apr 5, 2013 0:48:17 GMT -5
So which would you recommend for the ATM50?
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Post by carasdad on Apr 5, 2013 9:17:26 GMT -5
If the ATM-50 is stock....I would go with KOSO 5 gram sliders from Scrappydogscooters. They are REAL KOSO not imitation ones most sell. All customers that want to stay stock 50 have me put them in....take off is faster...and top end id 8-10 mph more. As for the big bore....NEVER run it lean or even slightly lean. I have seen no fewer than 5 customers who had another shop put on a BBK for them...and left the stock jet. All 5 had piston meltdown or cracked piston. My gf scoot is a 4T with a BBK and #82 jet vice #72 it came with. Her mileage is the same...but that is because she does not run WOT all the time....she rides it 'normally' and the extra torque from the BBK allows her engine to have to work less to cruise at 40.....where her stock 50 setup the engine was working hard and really revving hard to get to 40mph. Btw...a note to ALL on here...the youtube vids on installing KOSO sliders is dead wrong! They go in so the word KOSO is on top and visible. Most tell ya to put 'KOSO' up against the center of the variator..even MO from Scrappy's said this. Not attacking anyone...but that is the wrong way. I tried both and with KOSO facing the center there was barely even a slight improvement. I put them in with KOSO up and now take off is right now! Top end gets 10 more mph even. Sucks that KOSO sells a product without instructions when they make super quality products. After many attempts to email or call them....you eventually get through....and they will tell you... 'KOSO' goes up. So I asked why not one of the fine products they make come with instructions. No reply first few times....then was told items they sell are for a mechanic to install and the mechanic should know what to do and how to do it. But still...their parts rock..are top notch..and the first brand I seek when buying performance parts.. ;D
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Post by prodigit on Apr 5, 2013 13:08:45 GMT -5
why's koso so much better than other brands?
Does the price increase justify buying them, even if it's on a scoot that probably will retire in a year or two?
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Post by millsc on Apr 5, 2013 15:24:08 GMT -5
I have koso in my t3 and dr pulley in my tapout scoot the dr pulleys are slightly better and a doing a big bore kit without upjetting is a no no you may come close to being ok with the jetting if you keep the airbox and stock exhaust with a 72cc kit at least in the summer
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Post by carasdad on Apr 5, 2013 18:15:35 GMT -5
why's koso so much better than other brands? Does the price increase justify buying them, even if it's on a scoot that probably will retire in a year or two? Well I have tried 2 different sets of Dr Pulley. The claim tougher material and wear less. Wear less...yes it is true..they did not wear as the material is so durable....BUT they sure wore nice channels in an $  variator...cause the sliders are harder than our aluminum variators. The KOSO sliders do wear...takes about 8,000+ miles...but at $14.00 they were cheaper to replace than the $ variator was to replace..  I have tried Ninja and some generic brand green colored slider they sell on Ebay..but after about 2,000 miles customer came back saying he was losing speed. Opened the variator and talk about worn sliders...wow..looked like you took them to a bench grinder. To answer your question as to why I like KOSO...the Ninja and green cheapies on Ebay are so soft you can slice them with your thumbnail and they wear way too fast....the DR Pulley are tough as they say...almost like concrete and they wear the variator before themselves. That is why I like KOSO...they fall in the middle and I would rather replace sliders than an expensive performance variator after the Dr Pulleys eat it up.. I was blown away when I saw the deep channels they ate in my NCY and Hoca variators.  As Paul Harvey would say..."And now...now you know ...the rest of the story...."  |
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variator...cause the sliders are harder than our aluminum variators. The KOSO sliders do wear...takes about 8,000+ miles...but at $14.00 they were cheaper to replace than the $