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Motorized Bicycle General Discussion All topics regarding bicycles with engines.

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Old 06-25-2011, 10:18 PM
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GearNut GearNut is offline
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Location: San Diego, Kaliforgnia
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

Originally Posted by uuu? View Post

i just put my kit on and the Carburetor (New High Performance Gen B Carburetor from the GRUBEE 2010 SkyHawk GT5 66cc/80cc Angle Fire Slant Head Bicycle Engine Kit ) is leaking out of the filter on the back/red part.

i have never worked with a bike kit but i did put it together. it was running ok but it got a leak. it fluds with gas.

please help me, i dont know how to fix it and would like to know what to do before i try to fix it.
What an odd introduction, and first post.
Anyways, Here, I did a search on this site for you.
"It's a chinagirl. It's a sometimes fun little engine that often will break your heart. It's disposable.

Does not come with a fortune cookie."
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Old 06-25-2011, 10:45 PM
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Matheneyr3 Matheneyr3 is offline
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Join Date: Jun 2009
Location: Carolinas
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

Emergency repair for leaking petcock- cap from a beer bottle. punched a hole through with my leatherman, used as you would a regular gasket- Worked great..been on 4 months & still no leaks.

Have fun-Keep Riding!

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Old 08-02-2011, 02:49 PM
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anim8r anim8r is offline
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

If this is your 1st project, paint the bike.
Take it all apart, sand it, paint it, & put it back together. You'll get to know your bike & adapt to a mechanical state of mind.

Then before you put the motor on, ride it for a few miles with some screwdrivers & wrenches handy. This way you won't be going 30 mph when you find the mistakes you made when you rebuilt it.
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Old 08-10-2011, 06:10 PM
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rustycase rustycase is offline
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Join Date: May 2011
Location: Left coast
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

What A8r is really a wise idea...
So much to be learned from working on a bicycle!
Skills that will never be forgotten.

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Old 08-12-2011, 07:43 AM
mirage mirage is offline
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Join Date: Oct 2010
Location: england
Posts: 79
Default Re: Motorized Bicycle Take a Tip...Leave a Tip

hi all. finnally got my bike into a useable state, as the standard rear cog with the kit was 48 teeth, it was to high and burning out my clutch, so i got a 75tooth from blow by u. put that on with difficulty, as the chain clearance from the frame was a nightmare. as being a much larger dia, it was higher up the frame and getting narrower. i solved it by making 2 new thin washers ie rag joint. from a car innertube, drilled out the thick rag joint on the inside to take much larger bolts. advantage, the sprocket fits closer to the spokes, in fact butts up against them making a truer and easier set up. no wobble. then i had to use a thick spacer washer on the gearbox out shaft behind the 11 tooth sprocket to get the chain to line up. it all had to move over towards the the centre of the bike,

now it climbs hills very well, does not seem to be any slower. but i still need to try a 9 tooth drive sprocket on the gearbox drive, as i would still like more torgue. can,t seem to get one for my hoot chain drive box.

another simple mod, no one seems to have thought of is the standard idle chain tensioner. all you have to do is make a large 1/8 thick nylon washer, place on the outside. grease the slot and face, make a small wire hook, to put around the bolt. use a nylon lock nut, back to front as the standard bolt is not long enough. and a spring at 45 deg, pulling from the v calliper mount, make a alloy frame clip to go round the frame. adjust the tightness of the nylock nut to make a nice sliding action, may need to file the slot in the bracket higher for more range, but keep it a close fit on the bolt, no play. works fantastic. it is the large nylon washer that is the secret, stops it tipping sideways, for a proffessional sliding fit. bike now reaches 30mph pretty fast, need a 9 tooth on the box though, unless i can change the sprockets in the box to get the same results.

Last edited by mirage; 08-12-2011 at 07:47 AM.
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Old 08-13-2011, 01:35 PM
gphil gphil is offline
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Join Date: Jan 2011
Location: USA Georgia
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

Think I saw where you could order a tool to help get the chain threaded on the engine . I found that a old brake adjuster tool works just great. Of course most do not know what that is now days but us old guys do. None the less, works great, even with one end broke off like mine. lol
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Old 08-18-2011, 12:09 AM
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rustycase rustycase is offline
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

Here's a twofer...

The pic will show WHY a brand spanking shiny new china motor should be taken apart before starting.

This is a never - run, regarded mfg engine... and look how horrible the gasket lines up with the manifold ! It would seem they did not even try to get the proper gasket, let alone attempt to fit it properly.

AND, the gasket material is brittle!
It would have undoubtedly sent pieces into the cylinder in a short period of time.

and for #2. drum

The do-hickey rod thingy next to the manifold is a scrap of welding rod I smacked with a hammer a couple times, then dressed with a file to make a screw driver to adjust the idle mixture, and speed, on my cns carby.

Yah yah yah... I've had a gazillion little screw drivers with the magnet on the handles top and a pocket clip just like everyone else... and I've LOST 95% of em working on this or that !
So I made one... that I wouldn't mind losing !
It works well.
and I haven't lost it yet.
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Old 08-21-2011, 09:25 PM
bugnut bugnut is offline
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Join Date: Aug 2011
Location: Alabama
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

Great post Bikeguy Joe Im a new first time builder but will be going out tomorrow and get them bolts and plugs Just got my motor yesterday so its still in the carton will check tank and check for those shavings, Big thank you
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Old 08-23-2011, 11:46 AM
peppers peppers is offline
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

1.when riding in motor mode on a multi speed bike, its better to use a higher gear, if its a 7 speed and you ride in 7th gear all the time the bearings in the freewheel will wear out much quicker, first gear would be best to 3rd or 4th would be reasonable.

2. if you replace the stock engine mounts with higher quality ones and mount the engine well the little m6 screws are still not adequate, you hit a nice sized bump or maybe a few there eventually gonna break, you MUST reenforce your mounts with something or better yet devise an entirely separate mounting technique.

3. a nice quality epoxy that dose not desolve in gas and is not broken down easily by sunlight or heat has its uses. For example it can effectively be used as a simple and easy way to construct some mount adjustment hardware and is also useful to add additional strength to an already reenforced mount. An epoxy putty is useful to keep in your bag for temporary roadside repair purposes. Obviously it would be a mistake to glue your engine to your bike with epoxy and try to hit the road, try that and you'll probably die.

Last edited by peppers; 08-23-2011 at 11:49 AM.
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Old 08-25-2011, 08:26 PM
twelvestringtex twelvestringtex is offline
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Join Date: Apr 2011
Location: Houston, TX
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Default Re: Motorized Bicycle Take a Tip...Leave a Tip

sooo... this thread is HUGE... and I can't read 11 pages between now and when I'm supposed to meet with the dean.... and I have only my motorbike as transportation.... how do we quit breaking spokes? I'm shredding them with a Honda GX50 and shift kit!
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