my bike wont run

will 3501 · #1 11-07-2009, 08:22 PM

It seemed to bog down alot. now there seems to be no spark from coil i took off the magneto cover brown residue on coil and some gas inside it. Is it the cdi? i have no tester to check it. It has gas also in spark plug.

**2door** · #2 11-07-2009, 10:27 PM

Will,
You described the coil as having a brown residue. That might be normal. The coil wrappings are often dirty brown in color but you also said there was fuel present. Was that an oily residue in the magneto cover? That could be an indication of a bad crankshaft seal behind the magneto rotor (magnet). You can try two things. One is to remove the rotor and visually inspect the seal. Often the problem is the factory did not press the seal all the way into its bore and the rotor rubbed it and the heat/friction destroyed it. There might be evidence of that when you look at it. The other option is to seal the magneto cover with a silicone gasket sealer as well as the hole where the wires exit the case. Make sure there is a good seal at all points then try to run your engine again after the silicone has set. If the seal is bad it will cause a very lean condition due to excess air being drawn into the crankcase and the sealed magneto cover will prevent that and allow the engine to run normally. This is a temporary fix however because eventually the fuel/oil will collect in the cover and short out the magneto. Get back to us with what you find.
Tom

**Bikeguy Joe** · #3 11-08-2009, 08:33 AM

Try a new plug too. Mix your gas at 40:1 and run the bike for awhile. Check the color of the plug, it should be brown or black. Not really sooty or oily.

marts1 · #4 11-08-2009, 02:16 PM

About time I heard a black plug is not so bad as I can't seem to have it any other way.

)

will 3501 · #5 11-10-2009, 02:04 AM

Thanks for the info is there a way to test the magneto and cdi i cleaned out the cover should I get a new magneto and cdi first az then check the crankshaft rotor seal? its a 49cc grubee starfire ive got over 2000miles on it.

Cowboy Rider · #6 11-14-2009, 10:18 PM

2000 Miles on a 49 Grubee Starfire? Wow!

That's the engine I built this year and I've only got 600 ~ 700 Miles on it. (Running Great BTW!)

My Carb leaks and drips a lot. I'm not surprised if you may see fuel wetness in the Ignition cover plate. But I haven't necessarily had that cause a problem so far as I can tell. I've taken that cover off and dried it out a few times with Brake Cleaner to be sure that I'm not having a Spark concern.

But if you have 2000 Miles on your bike/engine... maybe the CDI is shot. I don't know for sure how to test that either, but at this point I'm pretty certain that you've already tried cleaning/replacing the Plug. And after 2000 Miles, I'd say that you have the Carb situation Well under control. (unlike me....)

Just me guessing here, but... I'd say that a new CDI would get you back up and running again.

2000 Miles. Wow. That's Great!

DonnnN · #7 11-15-2009, 01:50 PM

Quote:

Originally Posted by Cowboy Rider

2000 Miles on a 49 Grubee Starfire? Wow!

That's the engine I built this year and I've only got 600 ~ 700 Miles on it. (Running Great BTW!)

My Carb leaks and drips a lot. I'm not surprised if you may see fuel wetness in the Ignition cover plate. But I haven't necessarily had that cause a problem so far as I can tell. I've taken that cover off and dried it out a few times with Brake Cleaner to be sure that I'm not having a Spark concern.

But if you have 2000 Miles on your bike/engine... maybe the CDI is shot. I don't know for sure how to test that either, but at this point I'm pretty certain that you've already tried cleaning/replacing the Plug. And after 2000 Miles, I'd say that you have the Carb situation Well under control. (unlike me....)

Just me guessing here, but... I'd say that a new CDI would get you back up and running again.

2000 Miles. Wow. That's Great!

Well actually with good maintenance and care of the engine.. 4000 Miles is also possible.. i also heard of some of the guys here who had 6000+ Miles

GatorGuy · #8 11-15-2009, 05:52 PM

Quote:

Originally Posted by will 3501

It seemed to bog down alot. now there seems to be no spark from coil i took off the magneto cover brown residue on coil and some gas inside it. Is it the cdi? i have no tester to check it. It has gas also in spark plug.

I just had the same problem (no spark) and found out that water had gotten inside the magneto and was shorting it (I guess from the rain I got caught in the other day). Once I opened it and dried it out for a few hours, she cranked up like a champ again. 1,300 miles and still running well (just the standard minor tweaks here and there). Glad you got your problem resolved.