New 80cc no start.

Mike Bailey

New Member
Joined
Jul 19, 2016
Messages
29
Hi all. I finally got my 80/66cc engine installed on my 24in road master. So far its been a big job finding and making stuff work. The carb had to sit at a 45 degree. The muffler was hitting the pedal and needed bent slightly. The chain had to be shortened and the funky rear sprocket to me a while to figure out. After all that I go for the first start up and it will not start. I've checked for fuel and thats there because I have some coming from the muffler. Pulled the plug and there's no spark. I've checked for wiring diagrams and mine seems different from most.

Magneto has
Black/blue soldered(no white)
Cdi has black/blue
Kill switch is red and black

I was going to ground the magneto off the frame to see if that's the issue but I wasn't sure if I'd break something or short something. I'll get some pictures tomorrow. Thanks. Mike.
 


crassius

Well-Known Member
Joined
Jul 23, 2012
Messages
4,575
hard to tell without pics, but fuel from muffler and mention of a 45 degree angle on carb makes me think motor is full of fuel

for wiring, go black to black, blue to blue and don't hook up the kill switch while testing
 

KCvale

Motorized Bicycle Vendor
Joined
Apr 18, 2010
Messages
3,518
Hi all. I finally got my 80/66cc engine installed on my 24in road master.
So far its been a big job finding and making stuff work.
The carb had to sit at a 45 degree.
The muffler was hitting the pedal and needed bent slightly.
The chain had to be shortened and the funky rear sprocket to me a while to figure out.

After all that I go for the first start up and it will not start.
I've checked for fuel and thats there because I have some coming from the muffler.
Pulled the plug and there's no spark.
I've checked for wiring diagrams and mine seems different from most.

Magneto has
Black/blue soldered(no white)
Cdi has black/blue
Kill switch is red and black

I was going to ground the magneto off the frame to see if that's the issue but I wasn't sure if I'd break something or short something. I'll get some pictures tomorrow. Thanks. Mike.
Hi Mike and Welcome.
Just so you know there is no such thing as an 80cc engine despite the claims, they are 66cc, and it is best when seeking help not even mention 80cc ;-}

Wiring the ignition is not hard...
The Black and Blue wires from the Magenteo Coil hook up to the CDI (Capacitor Discharge Ignition) module is just the Black and Blue wires.

For this to work the Magneto Coil in the engine needs to be grounded to the engine case so the spark plug has an engine ground to work with as that is it's other electrical contact point.

A kill button can be anything that connects the Blue and Black wires together shorting them.
Colors means nothing on the kill button.
 

KCvale

Motorized Bicycle Vendor
Joined
Apr 18, 2010
Messages
3,518
Thanks for the fast reply! Could I create a separate geound for the magneto to the case or frame?
The magneto is already inside your engine.



Note the new Skyhawk engine magnetos don't have a white wire, just blue and black.
 

Mike Bailey

New Member
Joined
Jul 19, 2016
Messages
29
The magneto is already inside your engine.



Note the new Skyhawk engine magnetos don't have a white wire, just blue and black.
I'm not sure which it is. My wires are soldiered to the magneto and there's no eyelet to the black wire.
 

KCvale

Motorized Bicycle Vendor
Joined
Apr 18, 2010
Messages
3,518
I'm not sure which it is. My wires are soldiered to the magneto and there's no eyelet to the black wire.
My troubleshooting procedure is simple these days.

Disconnect everything.

Ohm the black magneto wire to a head bolt, it should read a dead short.
If not, check the ground tab on the magneto.
Note:
The new skyhawk CDI's have no white wire, ground is the lower connector but it has a wire from it to ground.

Old style mags with a white wire have a tab out of the mag that solders directly to the mag base and they can come loose, just hold it down and re-solder.

Ohm the magneto from the black and blue wire, 320-380 ohms is ideal, an open or dead short means a bad magneto.

Ohm the CDI in the 10K-20K scale.
Red+ meter probe to CDI black wire.
Black- meter probe to the spark plug cap.
You should get about 6.9K ohms.

If not it could be a bad wire or cap.
Unscrew the plug wire at the cdi, use pliers or even cut it off and dig the junk out if need be and do the same test above again to the cable screw on the CDI.
If that works get a new wire and plug cap, if not you have a bad CDI.

If all of that is good there is only one thing left, the magnet.

That was indeed the problem with this repair on a new build with a 2014 gasbike.net front page engine kit.

When you pull the 4 bolts out of the magneto mount it should slam itself against the magnet, I mean to the point where it is hard to even get your first bolt in.
A weak magnet that lets you move the mag around pretty easily is not strong enough to create a spark which is what this repair had.

Magnet replaced, problem solved and my repair is done.
 

Mike Bailey

New Member
Joined
Jul 19, 2016
Messages
29
20170316_184930.jpg 20170316_184921.jpg 20170316_184952.jpg Hey guys I wanted to get back to you and let you see what I found. I got some picture of the bike and the setup. So far i think it's the cdi. I've ohm ed out the magneto at the wires and it's at 320ish ohms. I ohm out the cdi and it's reading out of limits or OL. I did a little garage push with the wire hooked to the magneto and it hit 32 volts once so is that right? I hope so.

Another question is that I have an old performance coil from my car that I wanted to know if I could use it? It's a crane cams one and it reads 1.6 ohms. Here's some pics of the build!
 
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