|
|
| Author |
Message |
| benandthe |
This post is not being displayed .
|
benandthe
Traffic Copper
Joined: 24 May 2010
Karma :  
|
 Posted: 02:36 - 18 Aug 2011  Post subject: 70cc moped top speed issues, carb maybe? |
 |
|
Got a semi-worrying issue (maybe I'm just worrying too much?).
Basically I've been tinkering with my 'ped alot since I re-registered it as a 70cc and re-insured it...
70cc Stage 6 Racing aluminium, single piston ring big bore kit,
Full mass crankshaft,
19mm carb with open air filter and a 100 main jet with 60 pilot,
Stage 6 racing Drive face.
The main issue I've got now is that once I'm hitting 60mph+ I'm now getting a fair amount of vibration in my feet and also it's bogging down if I full throttle her.
I'm thinking maybe the carb (well kinda know) the carb is not set up correctly, but still she responds very well right up to 60mph.
Anymore and it's a struggle 
Could also be that I'm possibly maxxing out the gearing (that's still standard, so could be spinning as fast as it can and just is causing vibrations now? (I've already done a gearbox oil change, so should be running as smooth as it can do, for what it's worth)
I'm thinking of going up in carb size again (standard was 17.5mm), a friend has a 24mm flat slide carb I can pick up friday.
Also could it be down to the rollers/variator?
Still got the stock variator with 6g rollers in there, they haven't been replaced in 3 months though, but I have no flat spots.
Here's my 0-60mph, on just over a 100 metre stretch of private track clicky.
Thanks in advance to anyone who can help!
I'm stumped! Any questions, please ask!
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS) |
|
| Back to top |
   |
You must be logged in to rate posts |
|
 |
| hmmmnz |
This post is not being displayed .
|
hmmmnz
Super Spammer
Joined: 22 Aug 2006
Karma : 
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| benandthe |
This post is not being displayed .
|
benandthe
Traffic Copper
Joined: 24 May 2010
Karma :
|
| Posted: 05:55 - 18 Aug 2011 Post subject: |
|
|
| hmmmnz wrote: | my guess is that you are over revving the motor,
i would change the output gear to lower the revs at top speed
you might have to condensate with a roller change |
I was thinking it could be along those lines, but with the Isle Of Wight Scooter Rally next Friday, I can't afford to replace everything, only one or two things. 
I'm using 6g rollers at the moment and, as I said, the standard variator.
Every tuning company I have spoken to have all said the standard variators are awful and they recommended changing it to a sports one.
Apparently they have different roller tracks, changing the way it accelerates and also the rollers are about 0.75g heavier than stock (also 6g, I've replaced the stock 6g's with new 6g's as I found they worked well with my old set-up,obviously not too well on the new one though, much more power, especially at mid-high revs.)
Will give it a go with new rollers Friday, when I get paid, problem is, parts wont arrive till Monday, cutting it a bit fine...
Thanks! 
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS) |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Acemastr |
This post is not being displayed .
|
Acemastr
World Chat Champion
Joined: 01 Oct 2008
Karma :
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| benandthe |
This post is not being displayed .
|
benandthe
Traffic Copper
Joined: 24 May 2010
Karma :
|
| Posted: 13:54 - 18 Aug 2011 Post subject: |
|
|
| Acemastr wrote: | seems to pull to almost 70 fairly well, how fast are you expecting this thing to go?! |
well my original target was 0-60 in 10 seconds or less, done that, so now I want it under 7, but with a top speed of around 80-90.
I'm going to have to change all my clocks and everything and get a digital set up, rather than the current analogue on there, can't tell what speed I'm doing at the moment once it goes over 70
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS) |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| cb1rocket |
This post is not being displayed .
|
cb1rocket
World Chat Champion
Joined: 30 Jan 2010
Karma : 
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| Ariel Badger |
This post is not being displayed .
|
Ariel Badger
Super Spammer
Joined: 02 Dec 2006
Karma :
|
| Posted: 20:35 - 18 Aug 2011 Post subject: |
|
|
Fit a bigger carb and you are going to need to open out the ports. Not an easy job especially on a 2T.
https://bidpro.comoj.com/port_2_stroke.html
____________________
Bikers make great organ donors, get 115 on your licence today. |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| benandthe |
This post is not being displayed .
|
benandthe
Traffic Copper
Joined: 24 May 2010
Karma :
|
| Posted: 00:23 - 19 Aug 2011 Post subject: |
|
|
I was thinking of getting a new carb, 24mm flat slide, can get one tomorrow, but she still bogs, more so when she is warm.
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS) |
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| TQ |
This post is not being displayed .
|
TQ
Trackday Trickster
Joined: 17 Dec 2009
Karma :
|
|
| Back to top |
| |
You must be logged in to rate posts |
|
|
| benandthe |
This post is not being displayed .
|
benandthe
Traffic Copper
Joined: 24 May 2010
Karma :
|
| Posted: 23:01 - 19 Aug 2011 Post subject: |
|
|
| TQ wrote: | You'll struggle to get above 75-80ish without modifying the gearing which is a pain in the arse to do because (I believe) you need a hydraulic press.
A Malossi or Polini variator shouldn't cost you too much and fitting it is a piece of piss. I'd try that before you go any further. |
Most of the gear-up's are pre-pressed anyway so that saves alot of trouble!
I've got to buy a new air/fuel mix screw as I lost mine earlier. anyone got one for a 19mm Dellorto Carb? PBHG (I think that's the right name. lol)
____________________
Sold: NRG 50cc, SR125cc, CBR125cc, Mito MK 1 125cc, Speedfight 50cc, Stomp 125cc, cbr125cc, NRG 172cc, CBF 125cc, Zip 70cc, stomp 140cc
Current: CB500 (waiting on DAS) |
|
| Back to top |
| |
You must be logged in to rate posts |
|
 |
Old Thread Alert!
The last post was made 14 years, 178 days ago. Instead of replying here, would creating a new thread be more useful? |
 |
|
|
Help & FAQs
Search BCF
Members
Groups
Events Calendar
rating
rating