Suggestions on engine to get?

GoldenMotor.com

KoOni

New Member
Aug 14, 2014
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New Orleans, LA
As I posted before, I'm entirely new to motorized bikes. I might be biting off more than I can chew as a newbie, but I'm wanting to put a motor on a fatbike, using a shifter kit (to avoid problems with chain alignment around the 4" tires)

So, I have all these awesome ideas as to what I want to create, and while I think I know the bike I want to use, I'm a bit more cautious when it comes to the engine. I don't want to put a ton of energy into something just to find out I've got some POS made in Vietnam engine that is going to ruin the entire project.

With that in mind, I'd love some suggestions as to what sites sell good engines, what brands to look for, and also what needs to be avoided like the plague. I'd prefer 2 stroke (used to own a 2t 150cc Vespa that I loved, and it was totally easy to maintain) and would love to get something with a little more kick than the typical 50cc engine kits that I see a lot of the time: 80cc would be awesome!

edit: Ok, additional question. After a bit of searching I've been seeing something about 66cc/80cc engines. Which is it? I mean, when one gets one of these what exactly are they getting?
 
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Davezilla

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Mar 15, 2014
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San Antonio Texas
The 66cc engines that Dax sells on his site are of nice quality and they can handle a few extra horses if you decide to upgrade, but these are the only "China Girl" type engines I'll buy for my bikes.
Now if you want an engine that'll really rock, he also sells a 50cc KTM clone engine that puts out 9Hp in stock trim.

Another option is to buy an engine from MotorBicycleRacing as his engines are of the same quality as the Dax engines and they have been proven to withstand at least 10hp in modified condition, he also sells a 9.5Hp version of this engine for racing bikes as well as lots of really well designed and built performance parts so you could build a beast of an engine if you already have a good stock engine.

Another option is the DeNardis engines sold at denardisengines.com, they are the ones who continued to build the Morini engines after Morini quit building them
 

KoOni

New Member
Aug 14, 2014
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New Orleans, LA
The 66cc engines that Dax sells on his site are of nice quality and they can handle a few extra horses if you decide to upgrade, but these are the only "China Girl" type engines I'll buy for my bikes.
Now if you want an engine that'll really rock, he also sells a 50cc KTM clone engine that puts out 9Hp in stock trim.
I'm guessing "China Girl" means engines made in China? Sounds like a romantic and pretty name for an engine that people should avoid. Or am I totally wrong? Are Chinese engines actually ok? As for the 50cc KTM clone, I'm not sure what KTM is but 9hp goes sound agreeable; I'm guessing though that even if it can do that with stock parts it still requires a bit of tweaking to get that type of performance out of it. I'm curious though why it would be that a 50cc would be preferable to the 66cc; In my experience with scooters the higher the cc, the more power, acceleration, and speed. Is there something different about gas bikes that I'm not getting here?

Plus, I'm always a bit suspicious about these sorts of things; Toyota advertised that the Prius could get way more gas mileage of what it really gets, just by saying "under ideal driving conditions" which really means "if you drive in a way that defies logic and all regular human behavior." If a big company like Toyota can get away with saying that, then I have to be a little suspicious when a small company that I'm still learning about makes grandiose claims about 9hp from a 50cc engine. Has anyone here used this particular engine, and can verify that it performs as advertised?

Another option is to buy an engine from MotorBicycleRacing as his engines are of the same quality as the Dax engines and they have been proven to withstand at least 10hp in modified condition, he also sells a 9.5Hp version of this engine for racing bikes as well as lots of really well designed and built performance parts so you could build a beast of an engine if you already have a good stock engine.
Same quality as Dax, but Dax is made in China. I'm confused. Anyway, "beast of an engine" sounds agreeable.

Another option is the DeNardis engines sold at denardisengines.com, they are the ones who continued to build the Morini engines after Morini quit building them
I'm guessing then that Morini engines were good? Totally uneducated guess from the names, but are DeNardis and Morini based out of Italy?

Sorry for all this nitpicking; I just want to make sure I'm getting the best engine I can while still operating on a budget. I don't suppose Puch, Genuine, Piaggio, Lambretta or any of the other well known makers of scoots, mopeds, or small-frame motorcycles sell engines for mounting on bikes?
 
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maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
No. The Chinese are the only ones currently marketing engines designed for bicycle frames.
There are several styles including rack mount and friction drives if you don't like the chinese in-frame kits.
Any aftermarket engine will take some work to fit on bicycle. The "Chinadoll" in-frame engine is by far the most popular, but Dax, Staton and several others make different style kits.
 

KoOni

New Member
Aug 14, 2014
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New Orleans, LA
No. The Chinese are the only ones currently marketing engines designed for bicycle frames.
Ah good to know. Always learning. If all engines are made in China then there's no sense in talking down about stuff "made in China" on this one. I'm just surprised that other companies in Japan, Europe, and the US haven't caught on to the market. Would be awesome to be able to fit a bike with a kit specifically made for this type of thing from Honda or Piaggio or Puch.

There are several styles including rack mount and friction drives if you don't like the chinese in-frame kits.
No, that's cool; I prefer in frame as I want to make something that looks a bit like an old cafe style motorcycle. (thus why I'm looking at hooking it into a fatbike.)

Any aftermarket engine will take some work to fit on bicycle. The "Chinadoll" in-frame engine is by far the most popular, but Dax, Staton and several others make different style kits.
So then, are all Chinadoll engines from the same maker, or is there a difference? I would assume that dax and the other sites I've seen are just distributors, but honestly have no idea.

For example, there's the "Black Flying Horse Engine Kit" from gasmotorkit.com:
Black Flying Horse
and then there's "the stinger" from bikemotorkit.com:
stinger
and dax has their F80 kit, which claims to be "made in the USA":
F80

All are in frame, all are 80/66cc (or listed as something similar, still not sure whether this means its 80cc, 66cc or what) Aside from colors and a few other superficial differences I can't exactly see any differences except the range in price. (ranging from $135 to $224 just in the sites listed, and going even higher on some other sites) Needless to say though, I've learned that when it comes to anything like this looks can be deceiving, and it does make me apprehensive to be buying something without even being able to look at it in person 1st.
 
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Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
The deal with Dax and Neil's kits is that either they go thru each one and correct the flaws left behind from the factory or they most likely assemble them in house, but they also have a very good source where the engines are more carefully quality controlled... One thing I can say for sure is that there is a big difference in smoothness and reliability with their engines compared to the ebay kits.

My latest engine is a Dax bottom end with the top end I modified myself and it runs very smooth with really good powerfrom just off idle all the way up to max rpm. I could make it a lot stronger but there's always a trade off between low end torque and top end horsepower. The 9.5 Hp race engines are a bit slow off the line but very strong once reved out.

Now with the other engines I've mentioned like the 9Hp KTM clone sold on Dax's site, Yes it does make the power it claims to make, but it's a much higher quality engine with far better parts and closer tolerances so it does run very strong. There are a few members in here running that engine and they have nothing but good things to say about it.

Then the Morini and DeNardis engines, these are in a totally different class, they do make the 11hp they claim with the 50cc engine but these engines are also very high in quality and precision with only the best parts in the buildup. It's not uncommon for a 50cc 2 stroke to be able to make this kind of power but it's going to happen at 11000 rpm or more. I know Blata makes a 40cc engine that cranks out 14hp at nearly 15000 rpm and they put it in their brand of pocketbikes about 10 years ago, the Blata Origami can easily do 60mph with a 200lb rider... and this is a 40cc pocketbike. The other secret to these horsepower numbers in such small engines besides lots of RPM is the liquid cooling so they can get awaay with more power without as much engine destroying heat.

For the China Girl engines, their quality can be anywhere from dirt poor to excellent depending on who's selling them and if they take them apart and go thru them before selling them or if they just send you a box that hasn't been opened since it left China... To avoid this gamble, it's best to deal with reputable dealers like the ones mentioned in here and not just find the lowest price on ebay and go for it.


Hopefully this clears the air on the subject some...
 

PIGEONHAWK

New Member
Aug 17, 2014
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Kingston
i have a 125 dollar engine w a light pipe capable of everything it is supposed to do including 9500 rpm smooth as silk. it puts the hurtin on alot of stuff for usability too.
 

PIGEONHAWK

New Member
Aug 17, 2014
15
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0
Kingston
i had one that roosted gravel up so high it was childlike amusement. i tame them down now bigtime. i like the loooong pull and a heavy crank
 
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KoOni

New Member
Aug 14, 2014
18
0
0
New Orleans, LA
The deal with Dax and Neil's kits is that either they go thru each one and correct the flaws left behind from the factory or they most likely assemble them in house, but they also have a very good source where the engines are more carefully quality controlled... One thing I can say for sure is that there is a big difference in smoothness and reliability with their engines compared to the ebay kits.
Ah, so in this case one is paying more for the quality assurance and personalized testing. Good to know.

My latest engine is a Dax bottom end with the top end I modified myself and it runs very smooth with really good powerfrom just off idle all the way up to max rpm. I could make it a lot stronger but there's always a trade off between low end torque and top end horsepower. The 9.5 Hp race engines are a bit slow off the line but very strong once reved out.
Makes sense. Doubt I have the expertise yet to modify engines myself: most I did on my old scoot was adjust carbs and replace tires (really easy on split rims. Anyway, I really prefer a quicker acceleration rather than a high top speed; even on the old vespa which could occasionally pop up to 60mph or more what I enjoyed most was being able to quickly jump up through the lower gears and maneuver around the narrow windy roads here in Nola.

Now with the other engines I've mentioned like the 9Hp KTM clone sold on Dax's site, Yes it does make the power it claims to make, but it's a much higher quality engine with far better parts and closer tolerances so it does run very strong. There are a few members in here running that engine and they have nothing but good things to say about it.
Once again, good to know. Do you know if that engine comes with all the fittings to hook it up to the frame? Even if its only 50cc it sounds like an awesome choice.

Then the Morini and DeNardis engines, these are in a totally different class, they do make the 11hp they claim with the 50cc engine but these engines are also very high in quality and precision with only the best parts in the buildup. It's not uncommon for a 50cc 2 stroke to be able to make this kind of power but it's going to happen at 11000 rpm or more. I know Blata makes a 40cc engine that cranks out 14hp at nearly 15000 rpm and they put it in their brand of pocketbikes about 10 years ago, the Blata Origami can easily do 60mph with a 200lb rider... and this is a 40cc pocketbike. The other secret to these horsepower numbers in such small engines besides lots of RPM is the liquid cooling so they can get awaay with more power without as much engine destroying heat.
At this point I love what I'm hearing, but I know that the maintenance is probably beyond my capabilities, let alone the budget.

For the China Girl engines, their quality can be anywhere from dirt poor to excellent depending on who's selling them and if they take them apart and go thru them before selling them or if they just send you a box that hasn't been opened since it left China... To avoid this gamble, it's best to deal with reputable dealers like the ones mentioned in here and not just find the lowest price on ebay and go for it.
I see; thus why you suggested Dax or Neil. Is there any word on gasmotorkit.webs.com? Their site says "QUALITY BICYCLE MOTORS-NO SUPRISES" and the site is a bit less shady looking than some that I've seen, but I guess it would help to know if anyone has any experience with them or their "Black 80/66cc Flying Horse engine kit."


Hopefully this clears the air on the subject some...
It really does, and I'd like to thank all of you for the info. Unless someone has something good to say about someplace else I'll probably go with dax or neil.
 

Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
Grubee kits are ok, but they're not as universal as the other kits, meaning not all of their parts are compatible as the other engines out there...

The GT5 type engines are nice and reliable with good manners after upgrades are made but parts can be harder to find

all of these engines are very simple with very few parts which makes them really easy to work on and gain experience on, if you mess up on a porting job, it's only $25 for a new cylinder or $10 for a new piston, or you can buy a pre ported cylinder from Fred or a few other sellers along with a Puch or fred head and a rampped piston for not too much more for an instant boost in power and performance. The cool part is that you can learn these engines really fast and easy due to their simplicity and upgrade as you learn. There's lots of info in here on that as well as lots of info on who the better sellers are and who makes the best upgraded parts etc etc... Read up in here and you'll find out just how easy these are to build maintain, and work on...
 

Theon

New Member
Jan 20, 2014
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FNQ Australia
Get the Dax or MBR motor.
It has a 40mm 'ballanced' crank.
the others have a 38mm crank that could be 'rough as guts'.
The longer stroke Will give you better pulling power.
The 'balanced crank will let it rev further and smoother.
The Ebay motors I have bought have required total strip and rebuild including the replacement of dodgy parts, then still be burdened with inferior parts.
You get what you pay for.
Unless you have fabrication skills, stick to the 'China Girl' you get everything you need in the kit and it can be installed in a few hours.