If you are having issues with your charging system on the air cooled 750 Kohler EFI

[mightymaxIV]

If you bought a Frontier with the 750cc Kohler EFI and you start to have issues with your charging system look out for the following-My EFI started to have charging issues after the machine got about 12 hours of use. I went through three new batteries in less then 6 months. I couldn't figure out what was wrong, the machine would charge fine without issues for awhile and then when I was out on a trail ride it would lose power start to sputter and then die. In every case the battery would be discharged to the point the starter wouldn't turn the engine over.

What?? Couldn't figure out what was wrong. Finally took the machine to a Kohler dealer and they checked the charging system-no juice being produced!!!

They pulled the engine and found that wires to the charging system had been routed wrong, the fly wheel gradually cut into the wires and shorted out the stator.

Once the voltage drops to around 12 volts with EFI the engine sputters and dies!!!!

Now I don't know if this was an isolated situation or if several of these engines were assembled the wrong way, but as you can guess this would be a very big deal for anyone traveling in the bush to have a failure (and breakdown) of the charging system and have to walk out several miles in the middle of winter.

I hope that this is the exception and not the rule but EFI owners might want to keep an eye out for any issues with the charging system.

[Noel Woods]

Good observation. The advances in technology (fuel injection, a charging system, etc.) do have trade-offs. It was just a few years ago that most of our machines had rewind starters as back-up. Those are pretty rare these days. A few years prior to that many started only with a pull start as they didn't have electric starters.

I even have a British vehicle from the 1950's with an electrical starter but also had a back-up starter that is activated like a Ford Model T's system. Looks like a smart guy could figure out a way even with all the electronics and bigger engines to rig up a back-up pull or wind up starter.

[msafi65]

The kohler liquid cooled engines with FI die at about 10 volts. As soon as the charging system quits and the voltage drops the computer fails. I've replaced many voltage regulators on them and keep one in my tool box at all times. I bring a jumper battery pack that will start and run a FI engine for quite a while with out a charging system.

[mightymaxIV]

The kohler liquid cooled engines with FI die at about 10 volts. As soon as the charging system quits and the voltage drops the computer fails. I've replaced many voltage regulators on them and keep one in my tool box at all times. I bring a jumper battery pack that will start and run a FI engine for quite a while with out a charging system.

Ya its sad to say but I will probably start carrying a battery jumper pack with me. I have had my machine die in the worst mud hole in Busco and again in the mud pits at boondocks. If it hadn't been for another forum member who had a jumper pack on both occasions I would have been stuck right there. Love the EFI but you don't think about these things until you own a machine and find out the hard way.

I glad my machine didn't die when I had my brother and his wife out in the marsh with bush up over our heads and mud so soft underneath that it would have taken us hours to walk out. I had told my sister and law she didn't have to worry about getting dirty and she had worn shorts that day. I would have never heard the end of it if my machine died that day.

[msafi65]

One draw back to being able to drive where humans can't walk out.

[needcoffee]

Good catch and thanks for the info. I have the same engine. Mine was routed on the non flywheel side. So had no issues.

One observation is that I never got my stator to produce more than 13.5 volts. When I upgraded to an alternator it now produces 14.2 volts. With all accessories on I have 13.5 volts at idle. The voltmeter digital readout on the handle bars maxes out at 14 volts. If you rev the engine and do not see a voltage increase at the display that would be an indicator that your charging system is potentially malfunctioning.