# GX670 charging issues



## SOTC

I recently purchased a machine with this engine and wiped the battery out that was on it. I bought a new one and a few weeks later had to charge it also. Today I got it running and pulled the positive cable and it died. I assume there is an issue with the charging system but don't know where to start. The previous owner has changed alot of factory wiring on the machine but the engine seems fairly unchanged. 

Also I checked compression and have 126# in the right cyl and 115# in the left. I assume thats fair but if not I would appreciate some advice.


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## LowRider

like a car i would start with the alternator. Since you mentioned the wiring without details its hard to tell. But if its not the original or an up to date harness you might want to think about replacing if a simple alternator fix doesn't help. Also like a lawn mower battery or any battery they tend to go dead over time if there not cranked and make sure you take the key out so it doesn't get left in the on position.


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## SOTC

No alternator that I know of, I thought these were magneto systems?


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## rotti1968

there is a charging coil under the flywheel , there should be 2 wires that come out from the engine housing, they should go to a voltage regulator. if you unplug those wires from the unit and start the engine, and take a multimeter set to ac voltage you should see at least 26 volts AC. If you do its not the charging system, its in the voltage regulator or beyond. When you say you remove the battery terminal from the battery the engines stalls? This should not happen, the battery is only there to start the unit the battery has not affect on the ignition system.If you start the unit and completely unplug the main harness from the engine and the engine remains running you now know its in the wiring . the engine should not stall when this is done. There is an issue in the wiring,key switch,relays etc.


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## SOTC

Excellent input, I will try that tomorow, thank you


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## LowRider

SOTC said:


> No alternator that I know of, I thought these were magneto systems?


i was thinking it was incorporated in the starter somehow. guess there is a difference. I'm not familiar with the bigger Honda's like these. just saw starter 20 amp alternator and figured. guess i have some studying to do.


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## 30yearTech

rotti1968 said:


> When you say you remove the battery terminal from the battery the engines stalls? This should not happen, the battery is only there to start the unit the battery has not affect on the ignition system.


If his particular engine has an after fire solenoid in the carburetor and the alternator is not working, then the engine would die when the cable is removed from the battery and the solenoid is no longer energized.


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## SOTC

Hmm, not as smart as I thought. I'm going out to the shop in a bit to try what Rotti sugessted.


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## SOTC

So heres a pic to make sure I did what I was asked. I pulled the wires from each coil and put one leg of my meter on each coil in the AC mode and got just over 5 volts.


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## SOTC

I tried seperating the wires after the (I think) regulator and the engine would not start which is why I traced back to the coils. I did not try to seperate the harness yet as my voltage was only 5 and wanted to see what you had to say about that and where I pulled the reading from


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## 30yearTech

Judging from the picture you posted, you are connecting to the ignition coils. 

The charging coil in underneath the flywheel and is not visible with the flywheel installed on the engine. The lead wires from the charging coils come out from underneath the flywheel and attach to the voltage regulator. You can unplug the leads there and test the output without removing the flywheel. You will want to test for A/C voltage at top governed no load speed.


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## rotti1968

30yearTech said:


> If his particular engine has an after fire solenoid in the carburetor and the alternator is not working, then the engine would die when the cable is removed from the battery and the solenoid is no longer energized.


Thanks 30year I forgot about that ....:wave:

in that photo the voltage regulator is just to the right on the wall of the machine. Your charging coils should be plugged into that unit, trace back from there for the 2 wires that go to behind the flywheel un plug and test your voltage there .


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## SOTC

Ok, I tracked down the grey wires and got 33V AC at full throttle, I traced those wires to this heat sink looking thing, is that my regulator? I am getting very little voltage (4ish) from the wires coming back out. In fact one wire is capped off. Thanks for the help so far:thumbsup:


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## rotti1968

That is your voltage regulator, to test the voltage coming out of there should be 12.5 to 14 volts or so dc not ac .With the engine running max rpms and you test at the battery terminals what is the voltage? The stator produces the ac voltage it will never overcharge, the way the windings are done it will only put out the max volts it was designed for, but if it was less then the spec on the stator then its bad. But it sounds like your issue is past the regulator or at the regulator if the above voltage is not there .


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## SOTC

12.07 V DC. Must be garbage? I have 3 wires returning, 2 connected to seperate posts on the starter and the other is just capped off.


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## rotti1968

is that the same voltage you have in the battery when its not running ? and if so replace the voltage regulator.


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## SOTC

Yes it is. I called the Honda shop and they said there is 3 different kinds and /i need the serial number off the engine. I can't find that number so I will bring the machine in when I get it back together. Thanks for all your help.


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## rotti1968

the serial number and type are behind the starter stamped into the block.


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## SOTC

Thanks, I found the numbers after taking the starter off and ordered the right part. 138 bucks later!!


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## rotti1968

no problem happy to have helped


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## Aaron Clark

LowRider said:


> like a car i would start with the alternator. Since you mentioned the wiring without details its hard to tell. But if its not the original or an up to date harness you might want to think about replacing if a simple alternator fix doesn't help. Also like a lawn mower battery or any battery they tend to go dead over time if there not cranked and make sure you take the key out so it doesn't get left in the on position.


This is my problem also, I can't even get the flywheel bolt broke loose.. Ive even tried an Impact.. Any ideas?


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## Milton Fox Racing

Penetrating oil?


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## paulr44

M18 FUEL™ w/ ONE-KEY™ High Torque Impact Wrench 3/4" Friction Ring Bare Tool







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