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Old 01-21-2011, 08:06 PM
bitsnpieces bitsnpieces is offline
Motorized Bicycle Elite Member
Join Date: Dec 2010
Location: Melbourne, AUS
Posts: 195
Default Re: am i doing it right?

Do you have a picture of how your current chain is?
Side shot and top shot so I can get a look at how tight it is and also how much of an angle it is on.

There can be a few reasons why it won't start from what I've read and experience; air leakage, wires, clutch pads, etc.

Firstly, with the fuel, did you put some plumbing tape before twisting it on? Some people say that doesn't work well as the fuel eventually burns through and evaporates outside (which happened to me before using the tape), but I haven't had this problem; tape works well for me.

By leaky petcock, do you mean when you put it to off, it still drips a bit? Try turning it up or down a little more. I found with mine, if I put it exactly on the dot where it says off, it drips ever so slightly. I have it pointing up towards on just a little bit, found that to be the sweet spot.

With the clutch disengaged (not holding it), it'll be hard because that's you pushing the bike and there's no where for the air to come out from the engine, so it's air compression. That's how the motor starts also. Clutch engaged (pulled in), pedal and gain speed (should be able to pedal freely, if not, clutch is loose), clutch out, compression and fuel and air mix and all, bang, it starts.

So that can be one reason why it isn't starting, air. Check the carb to make sure there's no leak between the carb and the engine, can't remember the exact name of that bit, but it's the part where you connect the carb onto the pipe which is connected to the engine; that spot is notorious for air leaks, the part where you have generally have a hose clamping to clamp the carb onto the pipe leading to the engine.
I will be putting some plumbing tape in there later today to make sure mine is true too; you can tell I love plumbing tape by this stage. LOL

Next, check the air filter, make sure nothing blocking it.
Try starting with the choke on (lever pulled up), mid-way, and off (lever down). I heard this can help with some engines depending on the quality and build of the carb.

If this is all check and it still doesn't start, my next idea is no spark or bad wiring.

Make sure black cables are connected to black, should be 3 in total. One from engine, one from CDI, one from kill switch.
You'll have 4 left, one of them white. Tape that up completely and stick it somewhere. The white cannot make contact with any metal parts connecting to or on the engine or it acts is an instantly kill switch every time you try to start. The remaining 3, put them together. Mine are blue, one the killswitch was red or something.

If that's already been done and it wasn't working, could be lack of spark. Take the spark plug out, make sure it's nice and clean, tape it down onto the engine so it makes contact, try pedaling and starting as normal and watch to see if there is spark. If there isn't, swap it, and if there is, put it back.

My last idea is clutch pads (which happened to my previous motor).
I would pedal, let go of clutch, but the pads did not catch on so as the rear wheel turned, turning the front sprocket, turning the gear on the other side, well... It didn't, which was the problem. I found the pads to slide across rather than holding on to turn the big gear, to turn the little gear, to turn the magneto.
I haven't personally fixed that yet, but I read somewhere you can sand the plate a little or something, get some friction back in there, and that should help.

Hope this all makes sense. LOL
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