Motorize a Bike




step by step instructions on how to motorize a regular old bike into a great awesome motorbike the bike gets 150+ miles to the gallon

Step 1: Get You Hands on a Bike and Motor

Things you need
-zip ties 2
-66 cc motor from Grubee Inc.
-warm place to work
-gas (1 to 20) parts oil
-gas tank
-kill switch
-318 chain
-chain breaker
-fuel line

Step 2: Mounting the Motor

mount the motor on the bike by screwing on the clamps under the top side, over the v frame on your bike.

1 the engine mounts on the frame"vee" above the pedal wheel sprocket
2 if the distance between the two bars exceeds the engine mounting span then additional spaces or welding brackets are needed. Mount the seat tube as low as possibla and then fir ro the front tube. ideal position it level.

Step 3: Chain/ Sprocket

1 the drive chain sprocket has a 35.9 mm dia. center hole and mounts on axle hub on the left side of the rear wheel against the spokes dish side in. The sprocket must fit ovet the hub in a perpendicular plane with the axle. this insures that rear chain sprocket spins true with the rear bike wheel.Spin the back wheel and check for wobble if there woble the chain can jump off.

1. for standard kit sprocket installation, locate sprocket on axle hub with curved side next to spokes, shinny side in.

2. If not pre sliced, cut the rubber isolator to the center, in order to fit INSIDE the spokes and around axle.Install the split steel retainer plates next to the rubber isolator and insert 9 bolts.Some kits supplied with 5 or 6 retainer plates for dual locking.

3. Secure with 9 bolts compressing the chain sprocket to the spokes. Note:Rubber isolators may be needed on both sides of sprocket for chain alignment on some non-coaster brake bikes.

4. Chain sprocket on the wheel must align within 1/2 cm to the chain drive sprocket on the engine. The drive chain can be easily shortened to the correct length. Special tools are required to remove and replace the master link when shortening the chain by removing links. Ideally, both your pedal drive chain and your engine drive chain should have the same tension.

part 2

1 Remove cover plate from left rear side of engine.

2 The engine comes with a drive sprocket to match the chain in the kit. . If the kit has a standard bike chain and a 415 HD heavy duty chain is desired, you must remove the narrow drive sprocket from the engine and install a wider tooth drive sprocket obtained from your dealer to match the 415 chain. Install chain with master link clip on inboard side of the primary drive sprocket teeth.

3. Use spark-plug and wrench to turn engine crankshaft sprocket to feed chain around it.

4. Fit chain, measure and remove excess links to assure proper length. Proper length is when top side of drive chain has one fourth inch to half inch deflection with the bottom side of the chain loop tight.
Reconnect the master link, and replace cover plate on engine.

5. Chain tension adjustments can be made by moving rear wheel. If both engine and pedal chains can be made to have equal tension then installing the idler assembly will not be necessary. Mount the chain idler on the wheel strut if the engine drive chain cannot be made as tight as the pedal chain.

6. Install supplied chain safety guard by attaching to engine and wheel axle struts.

Step 4: Fuel Tank

A) Attach fuel petcock to tank. Use Teflon tape to seal threads.
B) Attach fuel line from tank to carburetor. Best to use USA made fuel line like GoodYear or something . Factory supplied clear plastic line gets hard and crusty over a period of time.

Gas and Oil Mixture for Fuel ratio
The engine is a 2 cycle design, therefore, a gasoline/oil mixture is necessary. During the break-in period (1st gallon of fuel), the ratio should be 18 to 20 parts gasoline to 1 part oil. After the break-in period, the ratio can be increased to 20 - 25 parts gasoline to 1 part oil.

Step 5: Clutch/ Throttle and Kill Switch

Take clutch lever and slide it on over the handle bar and take the cable and thread it through the lever in the engine. When you pull the clutch the engine should disconnect from the back wheel so you can get it started.Then trim the rest of the cable because it is very sharp and will cut you when you pedal. Make sure you rescrew the screw so it wont come lose.

take the existing grip off the bike and slide the throttle on the right side of the bike. Use an allen wrench to tighten it. take the cable from the throttle and slide it on the carburator so when you pull the throttle you should feel some resistance when you twist it.

kill switch
Take the red wire from the throttle and attack it the the frame, Take the black wire and attach it to the white wire coming from the motor. When you push the kill switch you hold it so it will turn of not just stall.

Step 6: Spark Plug

Take the black box with wires coming off of it and take th black thick part and cap it over the end of the white thing "spark plug" on top of the motor . Attach the white black to the black and blue to blue.

Step 7: How to Start the Motor Up

before you start push the ticklier button and open the carburator. All the way first pull the clutch down and pedal until going kinda fast then release and twist throttle and pedal until it starts up then just twist to go faster.



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    84 Discussions


    10 years ago on Introduction

    Typically with a chinese 2-stroke engine, such as a pocketbike engine, it is usually recommended to be premixed at 25:1.Does the trick for me everytime, but if you use crap oil, you get what you pay for, right? I would probably personally recommend Shell 2-stroke oil or if you have brand name snowmobile oil, that works great too.

    7 replies

    Reply 8 years ago on Introduction

    I have one of these, same kit and everything. You need to use 40:1 for the first gallon to properly break it in. Then after that use 16:1. Also, the oil doesn't really matter. When it comes to two strokes, all oil is basically the same, as long as it is synthetic.


    Reply 3 years ago

    This is wrong, use 16:1 for first gallon, then 40:1 for all others.

    All oil is not the same. Synthetics come with a large variety of different additives, and oil weights/densities. Oil A mixed at 20:1 could equal oil B mixed at 40:1, or vice versa. If you don't know what ratio manufacturer recommends, always go with 20:1. And BTW, don't use 16:1 in these for break in. The instructions say this due to the availability of mostly bad quality in China, here we usually, not always though, use better oils.

    2 stroke jveta172

    Reply 8 years ago on Introduction

    whatt 16 to 1 first for break in then 32 to 1. 40 to 1 is to little oil in the gas you will score your piston and cylinder walls

    2 stroke jveta172

    Reply 8 years ago on Introduction

    really so they are not all the same ( even though they look the same ) mine is coming in the mail and their website says 16 to 1 for break in and 32 to 1 after break in

    jveta1722 stroke

    Reply 8 years ago on Introduction

    Ya. The manual i printed says 40, but the manual that came with it says 25. Both the same serial number. Oh nad i made a typo 16 first then 40. But now i use 32 as well.


    5 years ago

    Hey, I'm about to build it and was just wondering, about how fast does it go?


    5 years ago

    I have the same motor and just need the bike. Where'd u get yours?

    Electric isn't slower. That is only if you compare a 300 watt motor to a 1+ kw gas motor. For the same power motors though, electric will be smaller, more efficient, and will produce far higher torque and torque from a standstill. With gearing electric can be much faster and stronger.

    Power to weight, gas is faster hands down. And with the mileage you get, its gonna cost about the same in electricity.


    Reply 5 years ago on Introduction

    Wrong! Where do you get that? Even if you use a 1KW motor, which goes 55km/hr, you still use only 8c/km or R1,60 per 100 km. Compared to even 1 litre per 100 or R13/100. It is at least 6 times cheaper. Get your facts straight.

    Its still going to be cheaper per mile to use electric. gas has 36.6kwh per gallon of energy, but ice engines are very inefficient. Assuming a price of 0.12 cents US per kwh, that equals 4.3 dollars for an equvalent amount of energy as is in a gallon of gas. While a bit more pricey than gas, electric is over 4 times as efficient as the most efficient gasoline engines. Which these chinagirls are not. Therefore making electric cheaper to operate. And with electric, using lithium batteries can get you a very similar range figure, for roughly the same weight.

    but you have to buy all the batteries andcharge it when you run out with gas you can fill it back up and get on your way. also if you had all the batteries to keep up with a gas engine on a bike say a commom 5hp briggs and straton you would need a very large motor and some really high grade batteries that would most likley need to be lithium or li-po which are dangerous

    jveta172the tech head

    Reply 7 years ago on Introduction

    It would not tear it apart mine is 6.5 hp. I never have to recharge it, and the energy that it would take to make the lithium batteries would be worse thangasoline, esp. With 150 mpg fuel efficiency that I get on mine because its so light. Electric motors are expensive, fragile, not waterproof, and in this day and age just not as powerful as gasoline for the weight. I can put my engine through quite alot and I do. Believe me if I sprayed down an electric bike with a hose after a mountain ride it would not run again. It is also considerably safer because I can be heard.