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

[Al.Fisherman]

It's impossible to slide both the magnet and key on at the same time. The key needs to be in place first then the magnet slid on. Here is a trick........super glue key into place on crankshaft, let dry and install magnet. This way the magnet won't grab the key and pull it out of place while installing. Curved portion of key sets into the crankshaft grove.

 

[Apachekid]

Thanks again, Al. Im gonna vote for ya

 

[Al.Fisherman]

Thanks again, Al. Im gonna vote for ya

Keep paying attention, this ole dog can teach some tricks...

 

[577-Jersey]

I know its an old thread,,
But this does not sound like a timing issue,,more like a fuel cap not venting properly,,if it rev's smooth without a load but no power under load,,its a fuel problem,,I wouldnt rule out coil or air leak either

 

[V 35]

I'm wondering if the problem is mechanical , and not the engine . Best test I can think of is ... Remove plug [ no compression ]
Pedal bike around with clutch in, release clutch, and check for drag. If hard to pedal = chain too tight If it pedals OK with clutch
in, but pedals hard when released, clutch bearing might be bad, or flower nut way too tight. Since you have 2 bikes, a spare carb isn't a bad idea. I like the old SPEED brand carbs, cheap and simple. The mag / coil swap is easy enough, but possibly not the problem.

My first build had no torque until the motor broke in, after a couple tanks of gas, torque increased dramatically, and the clutch became much easier to use.

 

[577-Jersey]

Great info here guys,,
Im really enjoying myself!!

 

[Big Red]

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?Key wasnt sheared, but I didnt have a washer on back of magnet, just behind nut in front.......

No washer in back of Mag, so yer OK on that.
Big Red.

 

[KCvale]

Full Grubee tech bulletin here.

http://grubeeinc.com/USA/Magneto Mystery.html

 

[AdamOZ]

I know its an old thread,,
But this does not sound like a timing issue,,more like a fuel cap not venting properly,,if it rev's smooth without a load but no power under load,,its a fuel problem,,I wouldnt rule out coil or air leak either

Hello Jersey, funny you should mention the fuel cap issue, I have 2 bikes and the second was gutless wouldn't rev out and had very little torque I tried everything then one day I noticed the two arrows on the fuel cap were off center so I swapped caps and low and behold she goes great now.

I guess I can raise the needle back to the center from the very bottom