The solenoid seemed to work better with one polarity as opposed to the other, so that is the way I hooked it up. Got everything "done" last night but went to start it today and...nothing. Back to tracing everything to see what is wrong. the starter button was a little iffy, so maybe that is the open link.

If I need to replace the starter button with a momentary switch, then how heavy-duty does it need to be? You said the coil dissipates 25-36 watts so I am assuming I need a switch that will handle at least 3A. Probably 5A would be better. The starter button seemed to be a simple, heavy duty type switch with a large contacting area. Do I need something like that or will any 5A momentary switch be adequate?

Thanks for all your help.

 

You can use a meter to measure the resistance of the start button to see if it works. You can do this by measuring from from the starter solenoid actuating coil wires to ground if you want. This way you don't have to get at the switch pigtail wires if access is a problem. But keep in mind if you do this you are measuring both the switch and the interconnect wiring together. If it doesn't measure correctly then either one could be bad.

I would look for a 5 amp 100 volt switch. The biggest stress on the switch is when the starter button is released. The starter actuating coil in the solenoid has energy stored in the magnetic field it produces. When the current is interrupted (starter button released) the collapsing magnetic field generates whatever voltage is necessary to keep the solenoid coil current flowing until all that energy is dissipated. That energy is dissipated in a short spark across the switch contacts as it is released. This has a tendency to erode the switch contacts over time if it is not big enough.

The other part of the starter motor activation circuitry is the brake switch interlock. You've got to get 12 volts to one side of the solenoid actuating coil (the start button provides the ground to the other side of the solenoid actuating coil). That comes through the brake switch. So turn on the ignition, step on the brake and look at your brake light. Is it lit up? If not, then perhaps your brake switch is not working.

 

It was the starter button. I had a small momentary pushbutton that looks to be good for 5A (no ratings marked on it) so I wired that in and the starter turns fine. If it is not robust enough then I can easily replace it because I have pigtailed it to a different location aside from the handlebar switch.
Everything is now hooked up. Time to throw in a new spark plug and give her a try.

Spark Plug Questions:
1. My 50cc's plug died, so we threw in the NGK CR7HSA that was I was going to use for the 110. We tested the new plug and I saw that the spark looked a bit weak. It was surely sparking, but not bright, fat sparks. Is that normal? The quad ran perfectly after we changed the plug.

2. Is the NGK CR7HSA really a superior plug compared to the Autolite 4194? NGK is $4 and Autolite is $2. Not a big deal, but the previous plug did not last long in the 50cc. I just don't want to be spending twice the money for plugs all the time if I don't really have to.

3. Are CR7HSA and C7HSA the same plug except for the resistor? Cross reference table lists different Autolite equivalents, but I looked up the specs for the Autolite and 4194 apparently is a non-resistor plug? ??? Do I really need a resistor plug? Actually had the C7HSA in the 50cc before.

4. I end my rambling with a gripe. At local store NGK is $4, Autolite is $2. Online NGK is $1.63 and Autolite is $1.49. Why such a mark up locally?

 

Answer to #4 -- Don't got to Autozone for this particular NGK plug. For stuff like this I usually don't even bother checking prices between Advance, Autozone, Pep Boys, Napa etc. I just dropped into Autozone the other day and picked one up for $4. Called Napa and Advance and they each sell them for around $2. Shame on you, Autozone.

 

Brand new plug is in, starter button works but not firing up.
Checked and got an intermittent spark issue. Spark fires several times and then nothing. Try again and nothing...then a few sparks...then nothing. Maybe I'm imagining things, but it seems like there is a spark after I lay off the starter button.

Lynn -- I know you have tried to help diagnose this for others. I think I need to check the magneto voltages, but how do I do this. For instance, the red/black wire should have 40-80VAC right? So hook the meter to red/black and the other side to ???. Ground from the magneto? Just touch the engine block with the other probe?

I do have a Kazuma Meerkat 50cc that works fine, and I will check but I think they are similar years of manufacture. If it has a 5-pin CDI, then can I assume that it would work on the 110? How about the ignition coil? I figure with the spark plug not being the culprit the only things left are CDI, ignition coil or the magneto coils/flywheel. If I can swap the parts from the other machine, then it could save me some money not ordering extra parts I don't need.

 

(I hate people like me who keep updating replies without others responding)

Well, I tried the old remove the balck and white wire from the CDI trick. It seems to have worked and I now get a consistent spark. I will try to fire it up tomorrow.

Just so I don't forget, I did measure the voltages from the stator. 56v on balck/red and 0.14v on the trigger. Battery charge lead had about 5v and 3rd coil for lights had about 4.5v. I assume these are fine because at running speed those should go up to 11-13v.

 

I don't agree . More information is always better.

Classic kill switch issues. This is progress...

Battery charge stuff has nothing to do with spark. It only has to do with keeping your battery from going dead. The best test is to measure the battery voltage while the quad is running at a medium engine speed with headlights off. You should see 13.5 to 14.5 volts right on the battery terminals. If you do, all is well. If you don't then more troubleshooting is required, though this is something that can be put off until your quad is running (but do keep a trickle charger on your battery so it is kept up to fully charged).

 

Well, here comes more information for you, Lynn.

Tried this morning...nothing. Pulled the plug...intermittent spark again...then no spark. Switched CDI with other machine and no difference. Unscrewed wire to spark plug cap, applied PB, screwed back in and now appears to have a good consistent spark. Not super fat, but definitely more than my 50cc machine. I'm surprised that the 50 runs on the tiny sparks it has.

Anyway, I sprayed start fluid into the mouth of the carb several times and got nothing. One time got one little "pitter" out of it, but otherwise no fire. Checked intake valve for clearance. It had none, so I backed it out just a bit. Did not measure, but it now has slightest bare amount of play. Still nothing.

What's next? Check compression? Exhaust valve clearance? Timing? Get a new ignition coil? I'm stumped because if it is getting a seemingly decent spark and a straight shot of highly volatile fuel then I thought it would at least fire enough to burn through the start fluid.

Do I need gas in the bowl of the carb for things to work? I currently have no gas in there and the carb is not hooked to anything. I thought a straight shot of fluid into the carb would go right into the cylinder, but maybe not.

HELP....I'm going to start pulling my hair out soon.

 

OK...my compression tester did not have a 10mm fitting so I put my thumb over the hole. I was able to hold it there without being forced off at all. I tried on my son's 50cc and my thumb came flying off. I guess this means I have no compression. Also, I checked the valve clearance on the exhaust side. When I unscrewed the cover there was about 2 tablespoons of oil that drained out. This leads me to believe that I need rings. Should I just get a new piston at the same time? It's only like another $10.

Before I order parts, is this the problem? Is it usually rings that go on these machines and not something with the valves?

 

Remember that the available spark energy is directly proportional with engine speed. Thus the spark need only be weak at cranking speeds. It has to fire only once, which increases the speed, which makes a hotter spark, which is more likely to fire again, increasing the engine speed further, etc.

Cranking speed is roughly 600 RPM, idle is about three times that speed.