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Motorized Bicycle General Discussion All topics regarding bicycles with engines.

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Old 05-31-2015, 10:55 AM
newusercruiser13 newusercruiser13 is offline
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Location: forrestville NY
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Default I'm new i need advice....

I'm new to the game.... I have a raw questions for my fellow enthusiasts. I'm a bigger guy weighing about 265. I have created a 50 cc on an old Murray 3 speed.... I run a 41 tooth sprocket. On a flat surface I have okay speed, but on small and large inclines I have to a bit a pedaling. (a lot of pedaling)..... What can I do different? I plan on doing another build what can I do to build a better bike for me?

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Old 05-31-2015, 11:34 AM
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xseler xseler is offline
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Location: OKC, OK
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Default Re: I'm new i need advice....

Howdy and welcome to the pleasant side of the internet!!

One of the easiest things you could do would be to swap your 41t for a 44t....or higher. The trade-off would be a slightly slower max speed. Other things might include a less restrictive exhaust (usually louder), fine tuning your carb for better performance, porting your engine exhaust and intake, or a combination of these.

Best of luck in your travels!
You're never lost until you run outa gas.
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Old 05-31-2015, 11:43 AM
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Dave31 Dave31 is offline
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Default Re: I'm new i need advice....

Hello newusercruiser13 welcome to the forum.

I agree with xseler a bigger sprocket will help. On your next bike using a bike with more speeds in my opinion will help. Along with gathering as much momentum as you can before going up hills.
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Old 05-31-2015, 11:55 AM
_Spyder _Spyder is offline
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Location: Wisconsin
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Default Re: I'm new i need advice....

I'm by no means the most qualified here to answer your question, but I'll give you what I've got until someone with more comes along.

What I've picked up so far tells me a larger sprocket, a nicer head, or especially an expansion chamber exhaust for better low speed performance and more power respectively are all things that would help give you a little more umph on a hill.

Besides that, there's all the little tuning stuff like gaskets and bolts; take a few weeks off of maintenance and the bike will get a lot slower, in my experience.
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Old 05-31-2015, 12:13 PM
crassius crassius is offline
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Default Re: I'm new i need advice....

I also recommend at least a 44T for heavy guys - a 66cc motor can help a lot too.
Sometimes I sets and thinks, sometimes I jes sets.
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Old 05-31-2015, 01:24 PM
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2door 2door is offline
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Default Re: I'm new i need advice....

Welcome to the forum. I hope we can help you get a little more from your motorized bicycle. You've recieved some good advice but I'll ask how many miles do you have on the engine? A new or low milage engine will not perform as well as one with at least a couple hundred miles on it. They run better as they age.

Also, what fuel/oil ratio are you using. The kit recommended 16:1 we've found to be a bit too much oil. Drop your mix down to at least 24:1, 32:1 is even better.

Make sure the cylinder head fasteners are torqued to 120 to 140 inch pounds. Loss of compression due to a cylinder head gasket leak will kill preformance.

Good luck. Hope some of the suggestions help.

Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"

Last edited by 2door; 05-31-2015 at 01:26 PM.
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Old 06-08-2015, 09:23 AM
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LandSpeedRecord LandSpeedRecord is offline
Join Date: Dec 2014
Location: Tucson
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Default Re: I'm new i need advice....

Great advice so far from other members. Here is my 2 cents. You spoke if building another better bike next. First start with a good bike, avoid big box stores. Micargi bikes and cruisers are barely more expensive than box store bikes from some of the big web sites and are in another world as far as quality. I am not a fan of shift kits but in your case it is probably best. A 7 speeed Micargi cruiser with a shift kit from Sick Bike Parts one of the site sponsors here with a well built Chinese 66cc motor will climb any reasonable hill and give you good top speed. There is a member on here with a ton of quality shift kit builds that can maybe chime in but I know he strongly recommends the upgraded shift kit from them because of some of the bearings and I would definitely follow that advice. If you use quality parts like that for just a bit more money you will have an efficient and reliable bike. I am by no means a master builder bt have spent countless hours building and learning on here for my projects so feel free to pick my brain for what it's worth anytime.

Last edited by LandSpeedRecord; 06-08-2015 at 09:25 AM. Reason: spelling
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Old 06-08-2015, 07:58 PM
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Davezilla Davezilla is offline
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Location: San Antonio Texas
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Default Re: I'm new i need advice....

Welcome to the forum and I also agree you got good advise so far...
My question for your new build is do you plan on using the same engine or are you putting a new engine in this build? Are you looking for more speed or better hill climb? And do you plan on modifying the engine for more power or leaving it stock?
If you plan on getting a new engine for this build, you can't go wrong with a Dax 66cc since they're very well balanced, already have the good bearings installed as well as high grade hardware, these are the smoothest running engines you can get without spending too much extra, and the torque and power these have will make hill climbing a lot easier...

If you plan on keeping the smaller 49cc engine you can still get 66cc performance by gearing it lower and doing the mods like porting, raising the compression, and adding in a good pipe, but it's cheaper and easier just to get a 66cc and install it, not to mention parts for the 66 are generally cheaper and easier to get. But if you modify a 66 you can get some pretty impressive performance whether you're looking for more torque to get up hills better or more top end power and rpm for speed.
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