49cc starts when it wants?

[HoosierDaddy]

Please help? I got this scooter back about two weeks ago with start up problems, sluggish run , top speed about 25 and stalling issues. I noticed right away dirt in the fuel filter, so I changed that, still not right so I changed the carburetor. Still no luck, Spark was good, then tried compression test... which came back 60 psi.

So since customer was a little frustrated (only 165km) on the scooter, I ordered a 100cc BBK thinking that could make up for things since she had a desire for more power... anyway put that in then I was getting random spark still hard starting.

Now I started on the spark issue, I replaced the coil with a high performance coil, same issue with sometimes a spark sometimes no spark... I changed the cdi, no help... so I started to pull the stator, but then I noticed the ground from the engine was loose. I tightened that up, now I have spark, but it is still hard starting... will start when it wants too?

I have also checked fuel delivery by sucking on the vacuum from the petcock valve and disconnecting the hose from the carb to make sure I'm getting vacuum. I even drained the gas and added new gas, changed the oil, and put in a new spark plug.

Oh yeah, the kill switch, start button, and battery seems fine.

Sorry for the long post, but please help?

I do get it started randomly, runs great, idles great, works great till I turn it off and try to restart? ugh!!

[HoosierDaddy]

I forgot to mention that my gauge was bad on my compression tester, I bought a new on and I'm getting 150 psi now. Also valves are set at .0003

[HoosierDaddy]

With the throttle open, I'm getting over 200 psi. Is it possible it's out of time?

[HoosierDaddy]

I think I found my answer here:

Hi
Welcome aboard
Pleased to meet you
I would check your engines compression. most likely its very high causing the problems turning it over
How many head gaskets did you use most when you did the install most of us when doing a bbk install use at least 2 to lower the compression
Very roughly, 100-125 psi is good, 125-150 psi is very good, and 150+ psi is great. most of my bbk builds are around 190 to 195 anything over 200 makes for a very hard to start engine as the starters are not strong enough to turn them over at such a high pressure
So do a compression check and let us know the results
Hope this helps
Take care and ride safely
Yours Hank

Thanks inuyasha! :tup:

[HoosierDaddy]

We added an extra gasket, but still having the same issue?

Scooter will start every time with a 16v jump start??? Any ideas? Please?

Without the jump it is very hard starting, cranks over and over, but will only starts once in a while... once it starts it runs great. Still have 200 psi, but since it starts with a jump makes me believe it is electrical?

[Firehawk989]

We added an extra gasket, but still having the same issue?

Scooter will start every time with a 16v jump start??? Any ideas? Please?

Without the jump it is very hard starting, cranks over and over, but will only starts once in a while... once it starts it runs great. Still have 200 psi, but since it starts with a jump makes me believe it is electrical?

Might need to put in a battery with more cranking amps than the original. The stock one probably can't put out the amps necessary to turn over the engine fast enough to start it when cold. Does it start with the kick start?

[HoosierDaddy]

Thanks firehawk for the reply :) We tried that today and didn't work... Even though you would think that would make sense.

But, we did figure it out... One of the wires from the pick up coil to the stator was shorting out... I'm really not sure how that makes any sense? lol. But the scooter is fine now and has been delivered back to the customer.

[Firehawk989]

Thanks firehawk for the reply :) We tried that today and didn't work... Even though you would think that would make sense.

But, we did figure it out... One of the wires from the pick up coil to the stator was shorting out... I'm really not sure how that makes any sense? lol. But the scooter is fine now and has been delivered back to the customer.

Nice! Glad you sorted it!

These little bikes always have little quirky things you wouldn't expect to be wrong with them.

You re-jetted the carb for the 100cc kit right?