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89 sb50. Bbk. no balls 0-15mph
Posted: Sat Jul 06, 2013 12:34 pm
by Kevinstonge
Hi guys. I'm trying to finish up my lady friends E so she can start cruising. The E consists of
65cc unknown bbk
Stock carb with #85 main and k&n(semi restricted)
Oem unrestricted exhaust.
From a dead stop it struggles to accelerate to 10, but once around 15mph it will feel great. Nice and responsive and pulls right to 34. I thought it may need a fresh belt and maybe clutch shoes but everything looked great behind the cover.
I also did a plug chop and found a nice milk chocolate plug.
Any ideas?
Is the injector pump safe to use?( id like to keep it if possible. will the dio pump fit?
Is the pilot too small to handle the bbk?
Any help/comments/2 cents is appreciated. I'm not trying to make it a monster, just reliable daily cruiser.
THANKS!
Re: 89 elite e. no balls 0-15mph
Posted: Sat Jul 06, 2013 7:41 pm
by t8kinover.
are you premixing the fuel?
Sent from my SCH-I500 using Tapatalk 2
Re: 89 elite e. no balls 0-15mph
Posted: Sat Jul 06, 2013 9:16 pm
by swimmingfree
how minney gram rollers do you have in it now??? if you drop the rollers by 3 to 6 grams for the set it will help on the tack off...
swimmingfree
Re: 89 elite e. no balls 0-15mph
Posted: Sat Jul 06, 2013 9:36 pm
by noiseguy
Hard to say, but sounds like its running lean at lower RPMs. If so, it will be making bogging noises at low speed.
Or it could be weights... Or issue with your variator stuck in one position.
Re: 89 elite e. no balls 0-15mph
Posted: Sun Jul 07, 2013 5:43 pm
by Kevinstonge
t8kinover. wrote:are you premixing the fuel?
No, and I would like to keep it that way if possible. My friend is a 23 yr old female that has no mechanical background, and would prob mix it wrong. If premixing is 100% necessary for reliability, then please let me know.
noiseguy wrote:Hard to say, but sounds like its running lean at lower RPMs. If so, it will be making bogging noises at low speed.
Or it could be weights... Or issue with your variator stuck in one position.
I'm pretty sure it is bogging some at take off. Would a low rpm plug chop confirm this??
I always thought the sb50's had no variator.....?????
Re: 89 elite e. no balls 0-15mph
Posted: Mon Jul 08, 2013 3:13 am
by paulpauly7
yes plug chops can be done at any throttle position just use a new plug and google reading a sparkplug colour so you know what your looking at
Re: 89 elite e. no balls 0-15mph
Posted: Mon Jul 08, 2013 11:24 am
by Kevinstonge
I think I have a good idea what I'm looking at. I've always shot for a milk chocolate color.
If I in fact do have a lean condition in the low rpms, is it still safe to run since the most of the time it will be ridden at WOT??
There has to be someone on here running an sb50 or spree w/ a bbk/oem carb/oem exhaust. If so, PLEASE chime in!!
Again, should I be concerned about the stock oil injector not providing enough oil?
WOT plug chop

Re: 89 elite e. no balls 0-15mph
Posted: Mon Jul 08, 2013 2:36 pm
by Red Eft Performance
I would suggest you leave stock airbox intact. That will help with small/fixed pilot jet. Also try the mixture screw at about 1/2 to 1 turn out. That will also help with the small pilot jet.
85 main may be too small as well I would try going up on that as well. Without experience it pretty much turns into trial and error. A cylinder head temp. Gauge with help from meltdown.
Re: 89 elite e. no balls 0-15mph
Posted: Mon Jul 08, 2013 3:56 pm
by Wheelman-111
Greetings:
As far as I know, the E models have no variators. Single speed tranny and the single gear is "second", meaning 0-15 won't be blistering 34 is respectable for this engine.
Do what you can to maximize pump input, and 128:1 premix in the tank should satisfy the 65cc's needs. Eviidently it's gotten by with only the pump so far, but it may be at risk over time.
Re: 89 elite e. no balls 0-15mph
Posted: Thu Jul 11, 2013 11:59 am
by Kevinstonge
Thanks for all the help so far guys!
Red Eft Performance wrote:I would suggest you leave stock airbox intact.
I wish I had one... I'll try to find one on here.
Red Eft Performance wrote: Also try the mixture screw at about 1/2 to 1 turn out..
I think I'm in that ballpark. Ill check today.
Red Eft Performance wrote:
85 main may be too small as well I would try going up on that as well. Without experience it pretty much turns into trial and error. A cylinder head temp. Gauge with help from meltdown.
For the next chop ill be using the gauge from my aero. Hopefully I'm under 400F. If not ill definitely up the main jet.
Wheelman-111 wrote:Greetings:
As far as I know, the E models have no variators. Single speed tranny and the single gear is "second", meaning 0-15 won't be blistering 34 is respectable for this engine.
Do what you can to maximize pump input, and 128:1 premix in the tank should satisfy the 65cc's needs. Eviidently it's gotten by with only the pump so far, but it may be at risk over time.
Good to know about the single speed is only "second" gear.
I'm not sure there's anything I can do to maximize my existing pump. Anyone know if the 86-87 aero or se50 pump will fit this engine??
From here on out ill be mixing the gas 128:1. Thanks wheelman
Re: 89 sb50. Bbk. no balls 0-15mph
Posted: Fri Jul 12, 2013 7:17 pm
by Pete M
Does it idle, or do you have to keep revving it?
Re: 89 sb50. Bbk. no balls 0-15mph
Posted: Sat Jul 13, 2013 1:30 am
by Kevinstonge
Idles perfectly. No stuttering. I moved the mixture screw from 1 3/4 out to 1 out and it still sounded fine. I bit more responsive off the line, but still doggish. My plan is to fit a stock air box on and tune from there. Im leaning toward an 88 main, and 128:1 in the tank... Ill update as soon as I get the oem airbox.
Re: 89 sb50. Bbk. no balls 0-15mph
Posted: Wed Jul 24, 2013 9:58 am
by Kevinstonge
Got my oem airbox and new filter installed. I'm going to do a chop later today, I'm just curious where my temps should be with this setup. I'm assuming anywhere under 375 degrees is fine? I still have the 85 main in but I'm thinking of starting with the 90 and work my way down..
Re: 89 sb50. Bbk. no balls 0-15mph
Posted: Wed Jul 24, 2013 11:40 am
by bubonik
I'll be watching this thread
different scooter, similar issue

Re: 89 sb50. Bbk. no balls 0-15mph
Posted: Fri Jul 26, 2013 4:17 pm
by Kevinstonge
So i took it out for some test runs and here are the results.
-Airbox installed with new freshly oiled filter, 90 main, 128:1 premix-
Idled great. After 10 mins of idling the cht gauge read 212. Took it down the road and a WOT pull would get the temps to 290, but no higher. And no heat spikes when closing the throttle after a wot run. 0-15 felt less boggy, but still not great. top speeds reached 29 on the speedo. It definitely felt rich but I think it's mostly from the extra oil on the filter.
Chop
-K&N filter installed and not oiled.( do they typically come oiled or not?) also mostly restricted by tape. 90 main. 128:1 premix.-
Idled rough until I raised it about 1/4 turn. Temps got to a consistent 325. Spiked to 335 wot to closed throttle. Felt much nicer through the rpm range and definitely a lot more top end. 0-15 slightly better than with the airbox, but still slow of course. Top speeds rose to 33-34 via oem speedo.
Chop. Excuse the * pic and bad angle. Tigon ally I thought it looked lean, then remembered it was a new plug and originally all white.(haha). From what you can see in the pic it looks to be pretty brown on the left. I'd do another chop but its not my scoot and I don't want to put another dime or minute into it.

WOT
