We have a '95 Fourtrax 300EX that has had an intermittent charging problem. At first we thought it was a bad battery that wasn't holding a charge long, because being my dads quad, sometimes he only starts it once a month. He replaced the battery with another new genuine Honda battery, and the problem seemed to be resolved for the rest of that year. This was about a year or maybe 18 months ago. We're starting to think it's a charging issue because now it won't start even after as much as an hour of riding time. We'll pull start the quad to get it going, then keep it running and it still won't even try to click.
I have heard one other person say they had a problem with this on an earlier 300EX. Is this a common problem with these machines? Should we invest in a battery tender and just let it sit there between rides? I have the original battery in my '99 400EX, and it will often sit the entire winter without starting, when February rolls around I go out there in 10 below zero temperature and it cranks right up. This leads me to believe the battery should not be the source of our problem. Which way should we go with this now? We're familiar with troubleshooting these fourwheelers, and don't mind spending money on whichever new parts to make it work like new again, but I figure ask all you experts! Thanks in advance for your opinions!

 

First you want to check all your leads and ensure that they are tight and don't have corrosion under them. Take off the ground wire where they go to the frame clean them and put dielectric grease on them, this will keep them from corroding. That's the easy way. If that doesn't fix it than get the shop manual and start trouble shooting the system with a good voltmeter.

Hope that helps.

Smitty