GTO
08-27-2018, 07:01 AM
I bought an ATC70 in 2012 ended up putting a 110 pitbike engine in it from a almost new pitbike I bought.
ATC engine needed a new top end as well as cam chain, plus cam chain seemed like it had never been adjusted there were literally no teeth on the oil pump drive sprocket.
Crankshaft on flywheel was totally butchered had chisel the end of and cut the shaft shorter, drill a hole and tap a thread in it
Here is the thread I posted in 2012:
http://www.3wheelerworld.com/showthread.php/143289-Shock-find-on-ATC-70!
So I had the pitbike still and my daughter is tall enough to ride it now and ATC with 110 lifan still runs great, so I was going to try and source a pitbike motor, but I had look on Aliexpress and there was a complete new ATC 70 top end(head barrel piston) for a really good price.
So I ended up rebuilding the engine.
But I am having spark issues, I checked for spark before starting, spark was good.
Bike fired and die almost immediately, no spark at the plug.
I checked through everything and eventually found there was no gap at the points but I set it a few weeks ago?
After setting the points again there was a spark, but same story bike fires runs for a second or 2 and dies and again no spark.
I have tested the following:
Cap is 10.55 Kohms(its a 10Kohm cap)
Primary circiut on ignition coil is 1.4ohms
Secondary circuit is 18.7 Kohms(8.25 without cap)
Stator coil is 2.8 ohms and seems to get just over 6 volts on most pulls.
I set the timing using the light bulb method but is still slightly advanced(+/- 7mm from F).
The other thing when I was reassembling the engine I noticed the woodruff was damaged, I had to file slightly because flywheel would not go on.
Points and condensor are old ones but points look good.
Its almost like each time I adjust the points gap I have spark again but as it starts it looses spark.
ATC engine needed a new top end as well as cam chain, plus cam chain seemed like it had never been adjusted there were literally no teeth on the oil pump drive sprocket.
Crankshaft on flywheel was totally butchered had chisel the end of and cut the shaft shorter, drill a hole and tap a thread in it
Here is the thread I posted in 2012:
http://www.3wheelerworld.com/showthread.php/143289-Shock-find-on-ATC-70!
So I had the pitbike still and my daughter is tall enough to ride it now and ATC with 110 lifan still runs great, so I was going to try and source a pitbike motor, but I had look on Aliexpress and there was a complete new ATC 70 top end(head barrel piston) for a really good price.
So I ended up rebuilding the engine.
But I am having spark issues, I checked for spark before starting, spark was good.
Bike fired and die almost immediately, no spark at the plug.
I checked through everything and eventually found there was no gap at the points but I set it a few weeks ago?
After setting the points again there was a spark, but same story bike fires runs for a second or 2 and dies and again no spark.
I have tested the following:
Cap is 10.55 Kohms(its a 10Kohm cap)
Primary circiut on ignition coil is 1.4ohms
Secondary circuit is 18.7 Kohms(8.25 without cap)
Stator coil is 2.8 ohms and seems to get just over 6 volts on most pulls.
I set the timing using the light bulb method but is still slightly advanced(+/- 7mm from F).
The other thing when I was reassembling the engine I noticed the woodruff was damaged, I had to file slightly because flywheel would not go on.
Points and condensor are old ones but points look good.
Its almost like each time I adjust the points gap I have spark again but as it starts it looses spark.