Engine and Bike Suggestions

GoldenMotor.com

ren.geers

New Member
Aug 29, 2009
5
0
0
Maryland
I have no experience with motorizing a bike or engines in general so I would definitely appreciate suggestions on which engines types are the best and where I could get them. I was looking at some engines on ebay but I don;t know the difference between the different types(stuff like 2 cylinders). I also want to know what types of bikes are best to add an engine. I'm thinking about an 80cc because I heard they go faster. I have about $210 to spend on a bike and engine. Thanks
 

bseelbach

New Member
Jul 19, 2009
136
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0
USA
Your budget of $210 suggest a 2 cyl 66/80cc or 49cc.
Allow approximately $120-$170 for an engine kit delivered to your house.
Your best bet is to look at your local Craigslist.com for bikes. There are several options for cruiser or mountain bike suggestions on this site. Easiest installation will be on an older 90's bike with traditional 'v' frame with the smaller (not over sized) steel tubes.

Look on both sides of the page for sponsors that sell motor kits.
There is no 80cc, they are actually about 66-68cc but referred to as 80cc.
49cc and 80cc are supposed to have about the same top speed although 80cc have more torque. 80cc are also rumored to have a bit more vibration. Many states have laws that require under 50cc.

Read through the posts. There is a tremendous amount of knowledge here. Enjoy!!
 

ren.geers

New Member
Aug 29, 2009
5
0
0
Maryland
Whats cc stand for. How is 49 and 80 the same speed if 49 is less than 60? and do you have any brands for the engines that you would recommend?
 

bseelbach

New Member
Jul 19, 2009
136
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0
USA
cc stands for cubic centimeters. It is the displacement of the engine.
The difference between the engines is that the 49cc has a bore diameter of 40mm and the 66/80 has a bore diameter about 47mm. The bore refers roughly to the size of the piston.

I do not have a personal comparison of the different sizes but have read (from many threads) that top speed is roughly the same. The larger displacement has more torque.

Search the threads here. There are several vendors and reviews. There seems to be alot of variations between motors. Not necessarily between brands or vendors but literally each motor has its own quirks and personality.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Listen to what bseelbach has just told you. He speaks the truth. One of the most important things to look for before making a decision on which motor kit to purchase is dealer reputation, after sale support and warranty. Many of the members here have been burned by making their purchase from low priced ebay sellers who seem to disappear or become unreachable after the sale. If you check the dealers that advertise here you'll be seeing reputable sellers with good customer support. As for the power differences between the engines they are negligible. The difference in the displacement is not really enough to make a world of difference in power. Some claim that the 80cc, actually more like 67cc has more hill climbing ability over the slightly smaller motor. That is probably true but the fact is you might not be able to tell the difference. As for a bike, check your local GoodWill stores and Thrift, (second hand) stores. There are some great deals to be had there for a good foundation for your first project. Keep us posted on your build and we're here if you have more questions.
Tom
 

ren.geers

New Member
Aug 29, 2009
5
0
0
Maryland
Is two stroke the same thing as 2 cylinder? I noticed that a lot of brands are priced differently on the same the of engine. I've seen skyhawk, grubee and black stallion kits. Are any of those better than the others and which would you recommend?
 

bseelbach

New Member
Jul 19, 2009
136
0
0
USA
Apologies if my abbreviations confused you. When referring to "2 cyl engine", I meant 2 cycle, not 2 cylinder. These engines are single cylinder 2 cycle (also called 2 stroke engines).

As I previously mentioned, all of the engines seem to have slight quality variations. This is engine to engine comparisons as well as vendor comparisons. Some vendors are not very good at after sales service. Example: I noticed issues on my first kit out of the box and contacted the vendor (who happens to be a sponsor n here). Although they claim a 60 day warranty period, they would not return any of my 4 calls or 2 emails. I had to buy a new kit after one week!

On the other hand, some vendors have very good customer service.
 

Sydneysider

New Member
Mar 20, 2009
189
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0
Sydney
they have pretty much the same top speed because there is no difference in their piston stroke, ie amount of travel the piston does from tdc to bdc. that would mean their top speed would be both roughly the same. the difference is in the bore which is the flat area at the top of the piston which means the 66-68cc has bigger area would produce a bit more torque if going up hills..
 
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xlite

New Member
Jun 18, 2009
735
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ny,ny
I beg to differ. My 80cc bikes with 36t go about 5-10mph faster than the 50cc ones which will not even make it up a hill with that sprocket. I think most who claim same top speed refer to stock sprockets which limit both displacements.
 

Sydneysider

New Member
Mar 20, 2009
189
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Sydney
thats right if you have the 36T of course its going to be faster than the 44T.. with the same sprocket, since piston displacement is the same with each 1/2 revolution this means they would both be the same in terms of speed and revs..
 
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xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
thats right if you have the 36T of course its going to be faster than the 44T.. with the same sprocket, since piston displacement is the same with each 1/2 revolution this means they would both be the same in terms of speed and revs..
Not true. The 36t on both my 50cc bikes will barely get up to 22mph level ground. The 44t on these same bikes will do 28mph easy.

My point was there was a major difference between top speed of my 50cc bikes and 80cc bikes, specially when using a small sprocket.
 

Sydneysider

New Member
Mar 20, 2009
189
0
0
Sydney
just wondering dont these motors have the same stroke regardless of capacity? I know the 50cc doesnt have enough power to maintain top speed like the 80cc if they both used the smaller sprocket but what Im saying is their speed and rpm would both be the same regardless of the same sprockets they use. Put it this way, 2 bikes along side each other, one had 50cc and the other 80 using the same 36T keeping to the same speed, wouldnt theyre revs be the same? Im not disagreeing with you that the 80cc would accelerate quicker and reach the higher end speed because of the torque and power.. my main point here is the highest rpm before the things go bang taking into consideration that all components are pretty much identical in these motors except the bore.
 

saetta

New Member
Jul 29, 2008
155
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0
Central Missouri
My 26" single speed cruiser with a 49cc seems to have a higher top speed than my schwinn OCC chopper with the "80cc". Although the 80cc chopper climbs hills with ease compared to the 49cc cruiser. I base my results on the cruiser having 26" tires compared to the chopper's 20".
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
the 80cc would accelerate quicker and reach the higher end speed because of the torque and power.. my main point here is the highest rpm before the things go bang taking into consideration that all components are pretty much identical in these motors except the bore.
Exactly. In fact the 50cc will actually rev higher than the 80cc with a light load.

The issue is torque. My 50cc bikes, unlike the 80cc, just don't have enough to get up there with that small sprocket. Maybe the slant 50s do.