Hey guys new 2 the site but looks 2 have some great knowlodge on here. I have a 2005 hammerhead(um150IIR) bought it new about 6 months after I got it I had the pipe,air filter,carb jetting done when I picked it up I test drove it around the shop shut it off and as I went 2 load it on trailer it wounld not start tech said it blew a fuse replaced it and I was on may way (he said it was most likely cause from the mods done did not make sence but I went with it)
Fast forward to 2009 no problems with kart for 4 years noticed had 2 charge kart after every ride (ride weekend park during week) figured had 2 be the battery replaced battery still had problem and noticed when putting cables back on battery with the key off had spark when cables touched battery figured had a short but could not find it got pi** said it was to cold 2 ride/work on parked it. Well here is the nice weather son is ready to ride and it keeps blowing the fuse(s). What I have found is
(1) Key off have battery voltage going 2 bystarter assy(choke ?)
(2) Kart will run once fuse is blown dose not blow right away takes a little time
(3) at night headlights will go dim bright dim etc.. for awhile then fuse pops.
Is all this possiblee cause by the rectifier or somethings eles. O yea I have ohm out the grounds they seem 2 be good ? any help would be great my 9 year old the driving me crazy and does not understand why dad can't fix this tried 2 find trouble shooting/test chart but no luck and the dealer I bought from is out of business. Thanks ahead of time for the help

 

I have a wiring diagram for a 2005 hammerhead twister 150cc buggy, but I'm recalling that there are some major discrepancies between the published diagram and a lot of buggies out there in the world. One of the discrepancies has to do with whether the lights are AC powered, or DC powered. Another has to do with whether the CDI is DC powered or AC powered. Thus we may have to wing it a bit when analyzing the problem.

Major Clues:

1) Your quad draws current when you hook up the battery, even with the ignition off.
2) Your battery isn't charging.
3) You have voltage at the bystarter valve even with the ignition off and the engine stopped.
4) Something is consuming a lot of power to pop a 15 amp fuse (15 amps is what the wiring diagram says).

Tests:

Charge the battery, then hook up the battery cable to the quad wiring. You said it sparks. Verify this. Then unplug the voltage regulator, and repeat.

A) Does the sparking at the battery (when hooking it up) stop?

If the answer is yes then your regulator is bad. And it has probably been bad for 4 years (because you've had to charge the battery all this time). What concerns me is that now you're blowing fuses. Even with a shorted regulator the battery voltage applied backward across the stator should only draw 9 amps - not enough to blow a 15 amp fuse.

There may be another problem. 15 amps at 12 volts = 180 watts. Something has to be getting bleeping hot, or whatever is dissipating that kind of power without getting hot must be big and well heat sunk to a big hunk of metal (like the engine, and that points back to the stator in the engine, which shouldn't draw that much current).

Unplug the regulator and look for sparking at the battery first. Then check the value of your fuse. Is it really 15 amps? If it is ten amps then maybe a bad regulator could explain it all, else we may need to be prepared for additional problems.

Do you have a meter? The next steps will be measuring DC voltages, resistances of stator windings, AC voltages while cranking, etc. Meters are cheap these days, and they are a very powerful tool when it comes to electrical problems. $20 gets you a really good meter, harbor freight sells cheap but workable meters for $6 (sometimes on sale for $3).

 

Thanks 4 the input I will try this when I get home. And yes I do have a meter. Thanks again will let you know results soon

 

Ok did the check as you said and with regulator unpluged spark went away so I am ordering 1 tonight let ya know more middle of next week when part gets here. Fingers crossed that will solve all the problems. Also fuse says it is a 15 amp. Again thanks 4 the help did not want 2 start throwing parts at this thing

 

There doesn't seem to be a standard pinout for 4 pin regulators, so it is possible that you may need to rewire the connector to make it work. See this thread (and the thread it points to also) for more details:

http://forums.atvconnection.com/kids...sport-atv.html

Are you sure that the regulator you bought is for a 150cc GY6 quad? 110cc (and some other) quads also have a four pin regulator that use the same connector. They are not compatible with GY6 engines at all, and no amount of rewiring will make them work.

What are the wire colors on the four pin connector? While you waiting for the regulator the battery charge winding on the stator can be tested with your meter. After ID'ing the two stator output wires (from the colors) the resistance of the winding can be measured to see if it is range, and the output voltage can be measured while cranking the engine. That will give and indicator as to whether there are more problems to deal with when the regulator gets there.

If you decide to just give it a go with the new regulator, then start off with a fully charged battery. Plug the new regulator in and start up the quad. With the lights off and the engine running at a fast clip (3000 RPM) measure the battery voltage right on the battery terminals. If it read 13.5 to 14.5 volts DC then your charging system is working fine, and you need not do any further trouble shooting on the charging circuitry.

 

Lynn, sorry took so long 2 reply had some family things come up so kart got put on back burnner. (1) did not order regulator after your reply but found a company that I was able 2 order regulator by part # in my owners manual so ordered it 2night. (2) did the test on old regulator by your instructions in older post found these results(1 being top left, 2 top right etc. I think I have the regulator you show in picture) red lead on pin 1--pin 2 0.00--pin 3 0.00--pin 4 open
red lead on pin 2--pin 1 0.00--pin 3 0.00--pin 4 open
red lead on pin 3-- pin 1 0.00--pin 2 0.00-- pin 4 open
red lead on pin 4-- pin 0.519--pin 2 0.519--pin 3 0.519
The wires on the connector are:
pin 1 red
pin 2 yellow
pin 3 pink
pin 4 green

As far as the stator the wire comming out of it are green-white-yellow these are in a 4 connector (but only 3 wires) and also a blue/Lt blue and red/blk, they are loose not in a connector, ohm across the white to yellow check ok white to green nothing but I think thats what you were talking about it the battery charging post you had me look at.
Have not checked it by turnning it over was not sure what wires to have leads on and what voltage to look for? any other test I can do while I wait for the regulator to get here? once again thanks for your help and input

 

The regulator is definately bad. You have two shorted diodes out of 4 in the bridge rectifier (D1-4) in the linked post above.

1) Red is DC positive which charges the battery
2) Yellow is one side of the the stator AC output coil
3) Pink is the other side of stator AC output coil (turn to white @ the connector in the stator pigtails)
4) Green is ground

White and yellow are the two side of the stator AC battery charge winding. Green is ground. Blue/lt blue is the timing trigger signal that tells the CDI when to fire the spark plug. Red/blk is a high voltage AC winding that is usd to power *some* hammerhead CDI's.

Does the red/blk wire hook up to the wiring harness? Or is it floating free and unconnected? This is a major clue as to whether you have a DC powered CDI or an AC powered CDI. You need to know this if you ever want to buy another CDI - but it has nothing to do with charging the battery, and nothing to do with your battery charging problem. If the red/blk wire is hooked into the harness, and a red/blk wire appears at your CDI on the AC power pin then you have an AC powered CDI. If it isn't hooked up into the wiring harness then you have a DC powered CDI.

You should have 1-2 ohms between the yellow and white looking into the stator (disconnected from the wiring harness). You should measure no connection between these wires and ground (so your readings sound correct).

Disconnect the regulator. Measure the AC voltage between the two ends of the AC battery charge winding from the stator (between yellow and white, or yellow and pink, depending on whether you are measuring at the stator or the reguator connector). Set a kill switch so the quad won't start. Crank the engine. You should read about 9.5 VAC at cranking speeds.