Have spark and fuel, but wont start

GoldenMotor.com
fatdaddy

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
Norman is right about the chinese cold solder joints, THEY SUCK. But I think I mentioned that before. Look for that TINY copper wire that Norm told you about, And he's also right that it's easier to see if you take out the coil. SO TAKE OUT THE COIL.
THEN, Scape or sand or file CLEAN, EVERYWHERE it touches the engine case on the back side of the coil. Do the same to the case everywhere it touches the coil. The coil has to make a ground to the engine. If it's corroded from sitting in the rain then it may have lost the ground connection.
NEXT, Find that little copper wire and wire brush (or sandpaper) the solder connection and all around it CLEAN. (BE VERY CAREFULL TO NOT BREAK THAT TINY WIRE, It's a PITA to fix.) Then put another layer of solder on it. Don't forget the flux, unless you use resin core solder,Then it's not needed.
Replace the coil being carefull not to get too much, IF ANY, grease and oil on it. You don't want to screw it up after all that work.
After all of this, it COULD be a crapped out coil anyway. Coils are only about $12-$13 and usually free shipping. Most people don't like Boygofast but he sells the same chinese crap that everyone else sells as far as coils go, and usually cheaper.
http://www.ebay.com/itm/66cc-80cc-M...Cycling_Parts_Accessories&hash=item2c60a2d240
And again, Norman's right. ya gotta get an Ohm meter.
AND, OH YEAH. I just went back through this thread and NO ONE asked if you are using the white wire for the kill switch. NEVER use the white wire for ANYTHING, Especially the kill switch.
fatdaddy.usflg
IT'S YOUR BIKE, BUILD IT YOUR WAY.
 
Last edited:
B

BrandonG

New Member
Oct 31, 2012
40
1
0
Gainesville
Ok, I undid the wiring and had a friend who's an electrical engineering student check it:
mag:
4-6 ohms black to white
150 ohms blue to white
CDI:
7.5 Megaohms blue to black (same thing with terminals switched)
6.54 K Ohms plug wire to black

Thanks to fatdaddy for what they should be:
Magneto
Check Ohms between BLACK and WHITE wire. 2 Ohms
Check Ohms between BLUE and WHITE wire. 300-400 Ohms
CDI TESTING: Readings are approximate.
Use Ohm meter scale about 200-K
Positive lead on BLUE wire and negative lead on BLACK wire infinite (no activity)
Positive lead on BLACK wire and negative lead on BLUE wire. 135-155K Ohms.
spark plug wire and black lead. 2.5-2.7 K ohms.


Most numbers dont match. Im not sure if we had a bad meter or somehow messed up the checking or what. Maybe those are very rough as to what they should be and variants are ok? I dont know too much about electrical stuff.

I looked at the mag and there is some water condensated on the magnet, and there is what looks like rust at the bottom of the cover and the motor is only 3 months old. The little copper wire LOOKS fine, but who knows if it actually is. I attached a pic of the mag.

Apart from the CDI and mag (which I have no clue if either one is good or bad) Im thinking maybe the gas. it was mixed 11/7 (yea, one gallon lasts that long, alot more pedaling then motoring unfortunately). Could the oil have settled to the bottom so the motor is getting not much gas and tons of oil?

Thanks for all the help, Id be lost without yall

EDIT: Just looked at the mag cover and added a pic. I held it tilted about the same as it is on the motor. How much water was in there?!
 

Attachments

Last edited:
Norman

Norman

LORD VADER Moderator
Jan 16, 2008
2,606
7
38
71
pampa texas
Your question......How much water was in there?! My answer....Too much by the looks of it.

The ground wire is real badly corroded and by the depth of the water line I'm going to say all of your soldered connections on the coil are probably in bad shape.

Once mixed oil and gasoline don't separate, both are hydrocarbons.
this is a ball park number for the ohms you should see on the magneto coil.
white wire to frame/ground =2.5 not to much more and no less than 1.0 ohms
blue wire to frame/ground =280 or more ohms 300 to 350 is average
 
Last edited:
B

BrandonG

New Member
Oct 31, 2012
40
1
0
Gainesville
So that means I should order a new mag right?

Im thinking that Flex seal rubber in a can thats as seen on tv will go over the cover next time. Says its non-flamable and good up to 500F. Ill put the gasket on and tighten it up, then a quick spray all around the crack should seal it good. And probably silicon where the wires come out
 
Norman

Norman

LORD VADER Moderator
Jan 16, 2008
2,606
7
38
71
pampa texas
You might want to clean the rust off the coil and re solder the ends where the wires attach to the coil and give it a try.

Get a new cover gasket a little silicone on the gasket and the through hole where the wire go through. Best deal is keep it out of the rain/ snow.
 
Last edited:
fatdaddy

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
OMG, I just looked at the pic. It really was out in the rain. I dont think I would ever trust that coil again. I vote that you buy a new one. And you keep calling it a MAG. The MAG is the spinning MAGnet. The COIL is what you need. The venders sometimes call it a magneto coil, But COIL all the same.
ALSO, With that much condensation in the coil case you might have just as much condension in your fuel. I would drain that and use it for parts wash. Don't forget to drain the carb too.
Here's one even a little cheaper. Still free shipping.
http://www.ebay.com/itm/Magneto-Coi...Parts_Accessories&hash=item3cc933df06&vxp=mtr
fatdaddy.usflg
IT'S YOUR BIKE, BUILD IT YOUR WAY.
 
fatdaddy

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
Yeah Big Blue, A REAL kodak something. If I would have seen that pic in post# 1 he would have his bike running by now. You can see the waterline going across the coil, draining out of the wire inlet hole. So the coil was under water for God knows how long.
But like I said Brandon, Dont forget to drain that tank and flush it with fresh fuel. Same thing to the carb, Or just take it off and clean it again, just as easy. Water is a BIG NO NO in fuel. And put an inline filter on it. BGF is probably the fastest shipper, 3 or 4 days and you got it.
http://www.ebay.com/itm/80cc-49cc-M...Cycling_Parts_Accessories&hash=item2a15c1bc70
http://www.ebay.com/itm/80cc-Motori...Cycling_Parts_Accessories&hash=item2c665b0261
fatdaddy.usflg
IT'S YOUR BIKE, BUILD IT YOUR WAY.
 
B

BrandonG

New Member
Oct 31, 2012
40
1
0
Gainesville
While Im waiting for the magneto coil Im putting on a new tank altogether. Been meaning to replace the old leaking one but never got to it till now. Should have parts by the weekend or monday and hopefully have it running early next week.

I'll have a fuel filter and some type of sealant around the magneto case.

Thanks for all the help!!!
 
fatdaddy

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
That should do it bro. And really, ya gotta put a tarp or something over yer baby when it rains. I know people that keep them in the house, and sometimes the bedroom. I love my baby too, just not THAT much.
Heres a pic of my baby.
fatdaddy.usflg
IT'S YOUR BIKE, BUILD IT YOUR WAY.
 

Attachments

Venice Motor Bikes

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,271
1,810
113
Los Angeles, CA.
There's a 4th thing that you need besides air, fuel & spark... Compression! ;)

This might not be the problem, but does the engine seem to turn over way too easy while you're pedalling?
 
fatdaddy

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
Venice Motor Bikes said:
There's a 4th thing that you need besides air, fuel & spark... Compression! ;)

This might not be the problem, but does the engine seem to turn over way too easy while you're pedalling?
Click to expand...
BRO, Did ya see the pic of the coil? The thing was under water all winter. Would you trust it in one of your customer bikes? I wouldn't use it in any of my customer builds. I think it's beyond any hope that the coil is good.
But yeah, ya gotta have compression too. It's not a bad idea to check that also. Good call.
fatdaddy,
 
fatdaddy

fatdaddy

New Member
May 4, 2011
1,516
4
0
San Jose, Ca.
BrandonG said:
It feels like I have compression when pedaling and the gaskets look good. Thanks for the thought!
Click to expand...
Yup, coil. Also check the plug wire connection that screws into the CDI. And the plug connection itself. The plug wire just screws into what looks like the end of a wood screw in the CDI. Just make sure the screw is is clean with no corrosion. And bro, Get a tarp.
fatdaddy.
 
You must log in or register to reply here.
Top Bottom