2-Stoke Motor Stopped Running Before fully Broken-in

[shihabafi]

Hey all. I'm new here and don't know how these forums work, so please do share a link if this has happened before.

I just finished building my 2-stroke 80cc engine kit from BikeBerry, and (after having to wait a week for them to send me a replacement CDI because the original one was bad) I finally got her to start running, so I took her to the park to just do laps, nothing crazy, just let the engine do its thing.

At first it was rough, but it was slowly starting to get better. However, at one point the engine stopped giving me power. If I continued to pedal, it would still make noises, but it didn't want to run, and would keep trying to stop as soon as it could. I took a close look at the engine, and found that there was a leak at the base of the engine, so I assumed there was a leak there. Then I saw some more under the exhaust, so I thought perhaps it was that. So I took it off, inspected it (looked fine to me), and put it back on.

Then, I tried running the engine once more and and found (when it still refused to run by itself) that there was a leak coming out of the spark plug as well. This is my first time building a bike so I'm still very new to all of this, though I have slapped an engine into a car before. I've attached pictures below. Thanks for reading, all suggestions are appreciated.

 

[Venice Motor Bikes]

The leak at the base bolt is easy to fix... Simply take out the bolt, clean the area well & re-install the bolt with plenty of silicone sealer in the hole.

The leak around the spark plug is because you didn't torque the plug enough!

My first guess as to why it won't start is probably a wet (fouled) spark plug... throw that cheap 3-prong plug away & install a NGK-B6HS

Also... how much oil are you mixing into the gas?? (I prefer 32:1 mix right out of the gate)

Report back if that fixed the problems.

 

[Mossy]

There's a check list thread on here that's a good read
"So your HT bicycle engine won't start, well let's take a look" in the search

 

[shihabafi]

The leak at the base bolt is easy to fix... Simply take out the bolt, clean the area well & re-install the bolt with plenty of silicone sealer in the hole.

The leak around the spark plug is because you didn't torque the plug enough!

My first guess as to why it won't start is probably a wet (fouled) spark plug... throw that cheap 3-prong plug away & install a NGK-B6HS

Also... how much oil are you mixing into the gas?? (I prefer 32:1 mix right out of the gate)

Report back if that fixed the problems.

I took it out to test a bit earlier and it seems to give me power for a brief second or two spontaneously. But it's not consistent enough for me to realize what it is that I'm doing right and wrong. I've played with the idle screw, emptied the carb multiple times (took it off and cleaned it out as well), and adjusted the choke just to see what works and what doesn't. Nothing works.

I should note that I'm working with a very, very limited set of tools - literally just a socket set, a screwdriver, and a set of Allen keys. I'm not too worried about the leaks at the moment, as long as she runs.

I bought an NGK B6HS spark plug the other day (before I diagnosed the bad CDI), so I installed it once more and it still does the same thing. Just the engine making noises when I drop the clutch. I should note, however, that I found some oily mixture on the plug when I pulled it back you afterwards. As for the ratio, I'm running 16:1, since I found out about the lighter ratios after I already diluted the gas.

Please advise, thanks.

 

[shihabafi]

There's a check list thread on here that's a good read
"So your HT bicycle engine won't start, well let's take a look" in the search

Just going to post my response here so I and others can see:

Electrical:
1. Wiring: Red wire to red, black to black, check. The CDI had to be replaced under warranty because the previous one didn't work. Used a multimeter and found continuity between red CDI wire and spark plug wire. I don't know how to test for spark (without a bike lift), and every time I try doing it myself, I can't see anything. Please advise.
2. Kill switch: has not been hooked up yet.
3. Magneto: I do not have a white wire to test as per the message. What can I expect between the red and the black wires? I set my Ohms to 200 and got .33
4. CDI: (Ohms 200k) black to spark: 2.6 , red to spark: N/A

Let's stop right there… is that a bad CDI?