Quality Engines and Sound Questions

GoldenMotor.com

mkatt4x4

New Member
Aug 30, 2013
65
0
0
Canada
First off I am completly new, I have been trying to google search a few concerns of mine, but I ran across this forum and it looks interesting.

I need to know which are the best quality engine kits to buy for the 66cc/80 or higher. Sick Bicycle or Grubee Skyhawk is what I have been looking at, I heard the kits sold at Toys 4 Boys Motorsports is cheap chinese engine and components. What good quality engine kits do you suggest?


Second question is, and this I researched for hours. I need/want to silence the engine waaaaay down, is it possible to lengthen the exhaust, expansion chamber glasspack, wrapped the headpipe and chamber with wrap, reduce the intake noise somehow??????, or what else would you suggest. I guess I will have to try all these methods, because no one I have found has really silenced them, I bet you everyone wants them louder, but I dont want to draw attention to myself, I like to blend in.
 

xseler

Well-Known Member
Apr 14, 2013
2,886
151
63
OKC, OK
I have a Grubee Skyhawk that has served me very well.

I've made a custom exhaust for my bike, and as I was 'experimenting', I found that if you added some pipe after the muffler, it quietened it down even more.

Good luck in your upcoming adventure!!
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Several good vendors on the forum here and a couple vendors on ebay that have served people well, I have had excellent service with buying from forum members and also ebay vendors.

I do believe that some of the china girls are put together better than others, there are so many factories over there that churn these things out and some of them use lesser quality bearings and the castings are not as good as some of the others, but I still stick to what I've experienced personally and seen here on the forum and say, all of them are a crap shoot as to whether or not you're getting one that will be a good runner and fairly trouble free out of the box when properly installed and tuned up.

Some people that are very skilled are building some of these engines ground up and making many needed upgrades and then selling them at a premium price $500-$800, personally I wouldn't spend that kind of money on one of these engines but it is an option that seems to be good for those who want to invest that much in a few extra MPH and the look of the custom cyl. head and other goodies which I also like.

do plenty of reading here of the forum and you can make an informed decision on which way may be best for you to go, I have voiced my opinion somewhat reluctantly many times about certain vendors and the positive results I've had with their products, I kinda hate to say much because I believe there are others here that would give me the same positive opinions but I just have not done business with them yet and I hate to sound like I'm picking one above the other or promoting one above the other.

You are in the right place to learn all you will need to know about tackling your first build, several very knowledgeable people on here that will jump right in to be of help in any way that they can to encourage you get things done in a way that will hopefully minimize failures and problems and result in a safe, fun and reliable as can be motorized bicycle.
Welcome to this great bunch of motor bike lovers and I wish you the best with your first build.

Peace, Map
.wee.
 
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unknown03

New Member
Aug 8, 2013
22
0
0
USA
Just an additional info. Never purchase from ZoomBicycle, i've had 2 flying horse engines from them and i can say that there is no way those engines can beat this Grubee i have now from MotorizedBicycle Canada.
 

mkatt4x4

New Member
Aug 30, 2013
65
0
0
Canada
Thanks for the tips, unknown03, mapbike, xseler.

There seems to be so many engines out there, after just causually surfing.
 

stinky

New Member
May 21, 2011
84
0
0
The South
I bought a license plate sound deadener kit off of ebay from GT Products. It is same material as you get in kit. For like 4.99.
http://www.ebay.com/itm/LICENSE-PLA...764?pt=LH_DefaultDomain_0&hash=item19d2f938cc
I put in the sound deadening in 2 layers on the clutch cover and the dynamo cover. I have a video that I made, but I haven't posted on Youtube yet.
That killed the sound really well.
I was thinking that if you bought some heavy dense wood, lignam vitae, cocobolo,
Ebony (lol) nice piece of that is expensive!! but would accent my black motor. Cut to
size and bolted outside the motor would make a excellent noise deadener.

Some people put a mouse pad on outside, but I don't like that because it would hold water.

Oh and with what I have done it definitely has quieted it down. Not much louder than a lawn trimmer edger thingy. Make sure you put some cut down
rubber inner tubes over your frame!! If you can, find old flat linotype lead and use that!! Lead is even better!!!

http://www.youtube.com/watch?v=GUZcD5Cpe2I
http://www.youtube.com/watch?v=MdiWgdDPdNM



Some other guy on youtube puts bent pieces of tire between the fins to stop them rattling at higher rpms. This is good vid!!
http://www.youtube.com/watch?v=hg4RjQTw8kA&feature=related
 
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CTripps

Active Member
Aug 22, 2011
1,310
1
38
Vancouver, B.C.
Another thing you can do to change the sound is change the exhaust so it doesn't point at the ground, go straight back with it. Then the sound waves don't immediately 'bounce' off the pavement while it's running.

I recall someone saying that taking the muffler apart and (loosely) packing it with steel wool also reduced the noise. Don't know if it works, haven't tried it.

When I did the exhaust for my cruiser, I fabbed a bracket and welded it to the end of the exp. chamber to bolt the exhaust pipe on to it, with the pipe straightened so the muffler ran along the chainstay. Obviously, it sounds different to the beast because of the exp. pipe, but I think it is a little quieter.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I wood use the scouring pads instead of steel wool myself, I have tried the scouring pads in an exhaust just to see what it would do and it does quieten it down some but you will loose serious power in my experience, these little engines need to breathe good to run right and make good power, choking them with any extra back pressure has never been anything but negative in my experience.
If you dont care for the engine running at it full potential then you can quieten it down, but just be prepared for the MPH loss and the hill climbing power loss.

http://www.amazon.com/s?ie=UTF8&page=1&rh=i:aps,k:copper scouring pads

Map