Recommended upgrades? 48cc Grubee Skyhawk

GoldenMotor.com

Brent436

New Member
Feb 14, 2010
55
0
0
Massachusetts
Hey everyone,

I'm looking to pull some more power and speed out of my little 48cc Grubee Skyhawk.

1) I want to get a shifter kit but SBP is out of stock for the standard kit. How does the DAX shifter kit compare? I assume its pretty much the same kit as i cant imagine it being much different, but is DAX comparable quality to the SBP kit?

2) What carb do you recommend? I've looked at the CNS Carb and the speed carb on spookytooth. I was thinking the speed carb and putting a cone filter on it as ive heard good things about those, but the only thing is that it says its for a 66cc. Will this cause issues?

3) How effective would a boost bottle be on my motor? I can't find one for the 48cc but i was thinking of just throwing a 66cc bottle on there. With my carb and boost bottle upgrade i would be getting the pre-drilled, ported billet intake.

4) What do recommend for an exhaust upgrade? I was leaning towards the SBP Expansion Chamber. Its not too expensive and its tunable. I just don't want my exhaust to be too loud because i don't want to attract any unwanted attention (noise complaints from neighbors, cops, etc.)

I would appreciate any thoughts on these things or suggestions for other upgrades. Thanks for your input.

-Brent
 

Prasinos

Member
Dec 1, 2008
261
0
16
California
A. Don't buy a carb from any motorized bike dealer. Especially the $60 carb is very difficult to tune and has the same venturi size as the stock carb. But a carb from a well known company or take one off of a bigger engine if you can convert it somehow. Personally i have a 16mm Dellorto Sha Carb and the intake side is definitely not going to be the weakest link for a while.

Daxs kit is obviously stolen from SBP. Totally your call but to me it just seems like a dick move to buy stolen goods.

I wouldn't go with a tuned pipe for your 50cc. I bought a tuned pipe when i had a 50 and noticed very little to no difference in power as compared to a muffler sans baffles. The pipes are all made for 80s.


Just port match your intake and exhaust.. Make sure you have a good plug and wire and boot. Take off your air-box. The filter is fine but that box is way too restrictive, at least drill a few holes in the box to let it breath better.

if your bike isint too loud now. cut out some baffles till you get to a good compromise


Also, take off your head gasket for more compression, if you can get away with it take off the base gasket too if your daring enough.


last but not least, use a full synthetic oil and try a few ratios from 20-40:1. If you weren't running synthetic before youl notice it for sure.
 

Cabinfever1977

New Member
Mar 23, 2009
2,288
1
0
Upstate,NY
Get a smaller rear sprocket 36T or 41T, use a regualar carb: drill more holes in airbox,any other air filter will not breath any better unless its thinner, don't get boost bottle; it just boost your money from your pocket, if you have a black muffler buy a regular silver one; one without a cat,or take off cap and drill holes larger inside and put cap back on. Any other muffler will be alot louder.
 

crobo

New Member
Mar 24, 2010
94
0
0
boston ma
cutting holes in the airbox will do nothing for power, it will stop that annoying whistling noise when youre at WOT though.

yeah port matching, or atleast gasket matching is where its at, its easy and youll be surprised at the difference.

as far as a carb goes, the new speed carb is supposed to be pretty good, and a little bigger (18mm i think?). i have heard good things, but not used one myself.

boost bottles are useless, especially so if you don't match displacement.

exhaust is tricky... more restriction=less power= less noise. its all about finding a happy medium that works for you. try drilling a few more holes, one at a time, in your stock muffler. when you find its getting to loud, stop.
 

Brent436

New Member
Feb 14, 2010
55
0
0
Massachusetts
I have the style of stock carburator that doesnt have the box at the end haha. i ended up lucking out with that one. it has a filter, then wire mesh, then a slotted plastic holder to keep everything in. the plastic part looks like those stupid kanye west glasses so it doesnt whistle haha.

Suprisingly when i went to port and polish my ports, they were already done. i dont know how often this happens but the ports look absolutly mint, completely smooth with no jagged edges at the sides of the casting. so i just matched the gaskets to the ports and off i went. made a little difference in power but i want to get a new aluminum intake for better air flow. i think im going to start with getting the speed carb and billet intake once my shift kit is installed and go from there. thanks for all your input, its helped a lot.

-Brent
 

ruppster

Member
Mar 3, 2010
191
0
16
maine
Brent, just because the ports are smooth doesn't mean they're matched and matching the sufaces will make a difference. You have to make sure your tranfer ports are all even also. If you want to make more power with porting and be safe widen up your exhaust port a little bit but don't touch the hieght. Chamfer any ports that you touch and make sure all the factory ports have a good chamfer. Spend a few extra bucks and get a Mikuni or delorto carb. I saw a Mikuni for about $12 more than the speed carb so there's no reason to not buy a quality carb. boost bottles don't add power! They only eliminate sputter and bog when you crack the throttle, that's all they're intended to do. Do the free stuff first and pay close attention to the details then replace stuff. A quality intake and carb is a good start but if you won't get full benifit unless the porting is up to par. If you were to have a pipe made for the motor it would make a huge difference but it would be big money. Just my 2 cents Brian
 

Brent436

New Member
Feb 14, 2010
55
0
0
Massachusetts
Well ive got my shift kit coming in the mail. id go with just the 40T sprocket but i dont want to lose that low speed power. im really looking forward to going through the gears haha. if someone could post a link to where i could order the Mikuni or Dellorto carb suited for my bike that would be greatly appreciated. Thanks!

-Brent
 
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ruppster

Member
Mar 3, 2010
191
0
16
maine
Wahl bros.com has Mikuni carbs. I have no experience with the speed carbs but I find it very appealing to be able to ready get jetting just about any where and they're a quality unit