70 mph? By bcgreatness (Read 6,590 times)

[bcgreatness]

Hi everybody. been checking out the scooter doc site for a few weeks now and finally decided to join. just got first scoot which is a roketa md-74-150. didnt know much about it much less that you can fine tune them. have been looking into the wide world of mods for the scoots. i discovered that my scoot has the gy6 motor and a long cvt case, going to take it apart tomorrow to see if it has an ac or dc cdi. what i was wondering from everybody here is if its possible to hit 70mph on the scoot that i have without going big bore or 200cc swap. i was thinking about doing the air flow upgrade ( foam air filter, aftermarket exhaust, 125#-130# rejet as stock on the gy6 is 115#) any advice from you seasoned scoot docs on how to schieve my goal? ALSO im in florida i read a post sombody said there were a few troops in florida. can i get a shout out to see if theres any close by? thanks for reading.

[drjeff]

Since you live in Florida, I don't believe there are any hills large enough to get it up to 70 as you go down hill.

So no.

[Bashan]

Howdy bcgreatness, a slightly belated welcome to the forum to you. Honestly, 70 is a huge stretch for a GY6 and simply not realistic. Steven at MonsterGY6 does extensive modifications on GY6s for a living and he's popped 70. But you'd pour a fortune into it and the life expectancy of the engine would be very short. If you want or need to go 70 get a 250cc scooter, it would be a lot cheaper and more reliable in the long run. Rich

[jct842]

unless you do both ends of the airflow thing forget it. the exhaust has to be done at the same time not just the intake. these scooters are great for what they are, and they are not a 70mph scooter. the mods only are going to help performance in their normal speed range, like get to speed quicker type of thing.

[bcgreatness]

Nov 28, 2011 8:57:47 GMT -6 jct842 said:

unless you do both ends of the airflow thing forget it. the exhaust has to be done at the same time not just the intake. these scooters are great for what they are, and they are not a 70mph scooter. the mods only are going to help performance in their normal speed range, like get to speed quicker type of thing.

Oh ok. So the air flow upgrade, a new cdi, iridium plug (have a torch but want to see what all the fuss is about) maybe a slightly heavier roller/slider weight would only help the acceleration and only add a max of 5 mph more? I am satisfied with its overall performance it tops 57mph on flats and 60 down hill (its some what hilly here )and it gets there fast. Was thinking about adding a few mods in hopes of atleast 65-70 on the flats but I guess 70 wont happen. From experience would it be worth it to add the mods listed above? And if I did add those mods would I atleast hit 60 - 65 on the flats? Thanks for you words of wisdom everybody

[bcgreatness]

Where did you find that fancy chrome luggage rack? I bet that ads alot to the top speed lol

[Alleyoop]

Bcgreatness,
To really get more TOP END out of the 150 put in Taller Tranny gears. If you do not up the displacement of the motor and leave it the way it is only go 2 up and 2 down on the gears.
So if yours had say 14/51s just go with 16/49s that will get you anywhere from 6-10 mph more on the top end. It also depends on your RPMS and torque of your motor that is why I say 6-10mph gain.
Lefty

[Alleyoop]

HAHAHA!! Good one BmWxPR
Alleyoop

[mike6736]

I gad a young guy today tell me his chino scoot would out run my Honda Reflex...He said he gets it up to 70 mph... A stock 150cc with out even a name on it. I said even if you could go 70 mph where would you like me to meet you when you get there...

Mike

[tvnacman]

lol Mike ,

Guys listen to Alley , the GY6 has plenty of tork , the speed is in the gearing !!!!!!! On my 150cc stock everything I was able to get 50mph . I changed the 12g rollers to 13gram sliders I picked up 10mph its a little soft on the hills . I won't call it a high proformance variator , just one with a larger diameter . Alley ordered one that I linked him to before I did . Alley has installed it, from the feed back from him I can't wait to get mine!!!

John

[Alleyoop]

And that is a FACT JACK.
That Variator has a good low end ratio and good top end. I ran it with the 13gram rollers first cause that is what it came with. I did not like the lower rpms on my motor so I came back and put in 12g Dr. Pulley Sliders big difference. Today I had the sucker up to 7000k and still had a little more to go but had to back off due to traffic. I was cranking just about 65mph came back and took the cvt cover off to check the mark I put on the Variator and it still has about 3/16-1/4 mark left I shot for 1/8 mark left. So maybe 12.5 gram will move it up and just loose a little on the RPMS.
Alley

[ncredleg]

Dec 1, 2011 21:04:54 GMT -6 Alleyoop said:

And that is a FACT JACK.
That Variator has a good low end ratio and good top end. I ran it with the 13gram rollers first cause that is what it came with.

Okay, so , what is this variator and where can I get one.

[Alleyoop]

Ncredleg,
PM TVNACMAN you probably will pay less than I DID.
It is a 107mm Variator which will fit the 150s, that is the largest you can fit. The OEM they come with are usually about 1/2 inch in diameter smaller.

the 107mm measures 4 1/2 inchs across so measure yours, it will probably come in just a hair over 4 inchs.
Alleyoop

[mike6736]

My point was you can not ride for long periods at 65mph, for high speeds you need a larger bike. I have seen some 150cc scooters move out from a light like a bat out of #$@%.

Mike

[kz1000st]

Not to start a riot but if you're going to ride at 65 mph for extended periods you need a motorcycle. There are plenty starting at $500 on Craigslist, some even less that need work. Most have decades of life left in them and will do 65 mph with no stress.