Bike was running good, but now not...possibly caused by being left in rain...?

[Sg187]

Hi all, first post on the forum. Hello and thank you for listening/reading.

Here's the deal. 66/80cc kit from www.bekits.com.

Got it installed and had it running good for 3 days. Then suddenly it started to lose power, missfire, backfire on deceleration, and now it's doing all that and running WAY more rough - to the point where it shakes my arms and legs pretty bad, and won't idle - just dies if I stop giving it gas, and I really can't ride it because it just screams something is very wrong.

This could be a coincidence, or not - but this started occurring around the same time that the bike was accidentally left out in heavy rain. I can't say whether it was exactly after being left in the rain or not...but thought it should definitely be mentioned.

I'm at a loss. So far this is what I've tried:

- Removed, drained and cleaned carb, checked for proper functioning the best I know how
- Removed and cleaned air filter
- Replaced spark plug
- Drained and replaced fuel/oil mix (which is at a 20:1 ratio for break-in period as per the seller at www.bekits.com)
- Replaced fuel filter
- Removed chain gear cover - nothing obviously out of whack from the outside view
- Removed the cover to the left of chain gear cover - the electrical area with magnet (not sure what all that's called) - nothing obviously out of whack, but I don't know anything about what's in there
- Removed clutch cover - There is a build-up of fuzzy looking stuff along with the normal grease on the back side of the cover. Yeah, it just looks like fine fuzz, about the color of the air filter element - a dark grey, almost black.

I think that's it...along with a great deal of internet research.


Any ideas??? I greatly appreciate it if you followed this far.

Thank you,

Sean

 

[maniac57]

The first thing you should do is check under the front sprocket cover for chain rubbing.
It's quite easy to fix if it's rubbing:
http://motorbicycling.com/showthread.php?t=47030

Then be sure your engine coil (the small cover on the left side in front of the sprocket) is well sealed. ANY water in this case WILL lead to a failed coil. Check out the many coil threads like this one:
http://motorbicycling.com/showthread.php?t=27629

 

[Sg187]

The chain sure was rubbing, but I fixed that yesterday and it didn't have any effect on this issue. I'll definitely be sealing up the coil cover once I get this issue fixed, but I don't want to seal it until I get it running right again in case whatever I need to fix is in there.

Side note, I just did some more clutch adjusting and the friction issue seems to be gone now...so I'll edit that out of my original post.

Still running the same though.

Could an electrical problem with the CDI, magneto, coil etc cause the engine to run like this?

If I can get my hands on an ohm meter soon, I'll run the tests posted in that thread you linked me to - thanks!

 

[2door]

Welcome to the forum. I hope we can help you.

I need a little help with this sentence > " it shakes my arms and legs pretty bad, and won't idle - just dies if I stop giving it gas, and I really can't ride it because it just screams something is very wrong".

If the engine suddenly started vibrating badly I'd suggest you take a close look at your engine mounts. I hope you're not using any rubber in the mounts. If the mounts or fasteners are loose that will cause vibration and rough running conditions.

Have you checked the connections of your wiring? Those push-on connectors are notorious for bad electrical connections. We suggest those splices be soldered.
The kit spark [plug boot is also a frequent source of problems. It should be replaced with a good automotive quality boot and a spark plug with the top cap installed.

When you removed the magneto cover did you notice any moisture inside? Or an oily residue?

I don't know what you mean by "it just screams". Will the engine not idle? Is the throttle working properly?

If possible could you post some photos of your engine installation? That would help us make some suggestions.

Tom

 

[crassius]

my first guess would be that the coil got wet and may be still wet inside the covering - this could cause internal arcing that would rob spark at an irregular rate causing your shaking as the motor misses beats

you could try drying out the coil, but a new one would be best

without watching it run, it's hard to tell, this may fix it cheap or just get you a spare coil for when it does go bad