No need for speed

GoldenMotor.com

leftywoody

Member
Aug 23, 2008
405
0
16
Lagrange Indiana
I have 2 identical Black Stallion 66cc motors on 2 differant 26 inch bikes . One tops out at 22 to 25 MPH and the other tops out at maybe 20 or less both start easy and idle great . The clutch isn't slipping . The breaks are not dragging the kit sprockets are the same . The slower bike has not enough miles to be considered broke in . The faster bike has . The slower bike was accidentally run for a while with a very rich oil/gas mix and I thought it might have clogged up the muffler but I haven't checked it yet . Is that a good place to start and will break in increase speed 5 to 7 mph ?
 

Tohri

New Member
Aug 28, 2010
159
0
0
People's Republik of Massachusetts
Even though the kits are 'identical' they still vary considerably. Manufacturing Quality (Read: consistency) programs in china basically don't exist, So what happens is that you get motors with sloppy tolerances. Sometimes you get a good one, Sometimes you get a seriously sloppy casting, over/undersize parts, and bad bearings.

What I would do in your situation is Research the crap out of 2 stroke tuning. MacDizzy is a good place to start. Beyond that, All I really did was teardown the motor, look for anything rough, slagged up, or misaligned. Dremel everything to match: Transfers, transfer windows, exhaust port, intake manifold... I mean, just check your intake port at Top dead center. You'll see what I mean, as the piston skirt is probably blocking some of the port. Scribe a line on the piston, teardown the motor, and cut away the area on the skirt that was blocking the intake port. Make sure your piston comes down to the exhaust port's floor at Bottom dead center.

Things like this will improve performance and give you a smoother running motor than any aftermarket performance part. And it'll make the gains from all those shiny parts bigger.
I should organize a sticky or something for a quick guide to hand tuning these beasts
 

dag_29307

New Member
Jul 1, 2009
296
1
0
Enoree, Sc.
If you are going to do a sticky (chuckles quietly) could you keep the descriptions (of the parts and instructions) in layman's terms for the noobs who have no idea what is being said can understand, please? Just a thought.
 

Tohri

New Member
Aug 28, 2010
159
0
0
People's Republik of Massachusetts
Dag: I'll try. I'm usually good with these things, But there's a fair amount of technical lingo involved. Not like we're on the internet or anything where there's a magical wizard that can tell you what any word Ever means or anything.

I'd love to live in that world.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
You will likely get the extra speed you are looking for by simply getting rid of those stock mufflers or at least knocking all the junk out of them and drilling 4-5 3/8" or larger holes in the bottom of it so the engine can breathe better.


I have 2 identical Black Stallion 66cc motors on 2 differant 26 inch bikes . One tops out at 22 to 25 MPH and the other tops out at maybe 20 or less both start easy and idle great . The clutch isn't slipping . The breaks are not dragging the kit sprockets are the same . The slower bike has not enough miles to be considered broke in . The faster bike has . The slower bike was accidentally run for a while with a very rich oil/gas mix and I thought it might have clogged up the muffler but I haven't checked it yet . Is that a good place to start and will break in increase speed 5 to 7 mph ?