No power with Skyhawk 49cc.....help

Adams77

New Member
Joined
Mar 5, 2010
Messages
10
I bought two kits, one is the 66cc and the other is a 49cc both are skyhawk kits.

The 66 runs good and has a nice pull to it, the 49 wont pull at all. In order to keep it running you either keep the clutch in or you must pedal.

The engine will rev up with no load on it.

I have swapped the carburetors around and changed the plugs and I get the same situation. What do I do next?
 


Al.Fisherman

Active Member
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Aug 13, 2009
Messages
1,965
I bought two kits, one is the 66cc and the other is a 49cc both are skyhawk kits.

The 66 runs good and has a nice pull to it, the 49 wont pull at all. In order to keep it running you either keep the clutch in or you must pedal.

The engine will rev up with no load on it.

I have swapped the carburetors around and changed the plugs and I get the same situation. What do I do next?
Swap out both the magneto and CDI, check compression, and timing. Although not a problem at the moment, do a hardware upgrade on both.
 

Al.Fisherman

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Aug 13, 2009
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any procedures for checking timing?
Timing is determined by the position of the magnet on the crankshaft inside the coil. A key is what keeps the magnet in position on the crankshaft. The way these are built, the only way of checking is to pull the magnet as you can't see the key with the magnet installed, although you can see the grove in the magnet where it slides over the key and into place (under the nut). The position of the key while on the crankshaft and at TDC will be approximately the 1:00 position. The coil usually needs to be removed first, for easier access to the magnet.
 

Apachekid

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Feb 20, 2010
Messages
91
Runnin rough 66cc grubee

Hi Al!.....Hope you're not to busy today... I got a question for you....If I remove magnet will I be able to tell if key is in place on crankshaft? Also, whats the odds the magnet is not in right position? Im running real rough right now, like out of time, Ive checked all the obvious....no air leaks, head bolts tight, good plug and wire. Motor smokes more than normal...cant get any power, vibrates sittin on the centerstand.If it was my 340 Mopar, Id twist the distributor and that would be the end of it. Kinda of running out of ideas:cry:Help!..........Cheers, Apache
 

Al.Fisherman

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Aug 13, 2009
Messages
1,965
Hi Al!.....Hope you're not to busy today... I got a question for you....If I remove magnet will I be able to tell if key is in place on crankshaft? Also, whats the odds the magnet is not in right position? Im running real rough right now, like out of time, Ive checked all the obvious....no air leaks, head bolts tight, good plug and wire. Motor smokes more than normal...cant get any power, vibrates sittin on the centerstand.If it was my 340 Mopar, Id twist the distributor and that would be the end of it. Kinda of running out of ideas:cry:Help!..........Cheers, Apache
These engines are either in time or not. When you pull the magnet, inspect that there is in fact a key (half moon) installed. Do this slowly and the magnet will grab the key and get stuck on the magnet. If the key is in fact in place check to see if it might of got sheared. If it did and the magnet rotated on the crankshaft ever so slightly you will be out of time. I'll take some pictures in a few minutes.

Picture 1. Correct position of key way at TDC
Picture 2. Correct magnet placement.
Picture 3. Incorrect magnet placement
 

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Hajuu

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Jan 9, 2010
Messages
276
"The engine will rev up with no load on it. "

If you mean its revving with the clutch in, it's probably the idle speed screw. If its revving with the clutch out and no accellerator, it's probably that the needle or cable is sticking in the carb.

Not sure what itd have to do with the cdi/magneto :/
 

KCvale

Motorized Bicycle Vendor
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Apr 18, 2010
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Thanks Al, I appreciate it very much. Now I can see where I am! Excellent pictures....
Ya, thanks Al.
My 66 runs good up to about 22 and then starts running kind of crappy, missing, vibrating, and acting like it's not getting the proper fuel/air all the same time.

I am going to start with all the basic today like plug, leaks, air filter. gas line, etc, but it's nice to have your pics about timing handy here.
I guess there is no timing mark on the motor so you could use a timing light?
That would sure be handy.
 

Apachekid

Member
Joined
Feb 20, 2010
Messages
91
These engines are either in time or not. When you pull the magnet, inspect that there is in fact a key (half moon) installed. Do this slowly and the magnet will grab the key and get stuck on the magnet. If the key is in fact in place check to see if it might of got sheared. If it did and the magnet rotated on the crankshaft ever so slightly you will be out of time. I'll take some pictures in a few minutes.
Say Al,
And the best way to reinstall key? put key in magnet first and slide into slot?
With the curve side of key going into slot on crankshaft? (key was stuck to magnet when I pulled it off) Or is that wrong?:confused:
Key wasnt sheared, but I didnt have a washer on back of magnet, just behind nut in front.......
 
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