Partzilla Live Q&A with John Talley – May 06, 2022

John Talley returns for another edition of Partzilla Live Q&A, answering your motorcycle and ATV repair questions.

ATV repairs were the topic of the day in this session. Check out some excerpts from Partzilla’s latest live Q&A session below, and tune into our YouTube and Facebook channels every Friday at 3pm Eastern for the next edition. 

Partzilla Live Q&A 05-06-22

Honda ATV

Can a bad rectifier cause a no-spark on a 2013 Honda Rancher 420?

John Talley: Chances are you’re not going to run into that particular scenario with a bad rectifier not allowing it to spark. Now with that being said, part of the charging circuit which is the stator, has wiring associated with a trigger that could cause a no-spark condition. And that association with the ignition system could cause a no-spark, but a bad rectifier? I kind of doubt it. That would be a long shot, although not impossible because the wires are more or less intertwined.  

Polaris ATV

I have a 2010 Sportsman 500 and when I turn on the key, the RPM needle bounces everywhere and sometimes it dies. Other times it idles and won't throttle up, but sometimes it won't even idle. Is it bad fuel? 

John Talley: That sounds like an electrical issue you’re having there. This seems to be systematic, in other words, it seems to be a global problem that you’re having. And when that usually raises its head, most times it has something to do with either your battery voltage or battery ground, or the engine ground. So start by checking your battery voltage and see what you’ve got, and then really check those grounds. Everybody pays so much attention to the positive side of the battery, but actually the negative side is just as, if not more important. And it can cause some of the erratic conditions that you seem to be experiencing. Even if it looks good from the top side, go ahead and take that negative side off the post, make sure there isn’t any type of corrosion under it. Get it cleaned up, put it back together. Add some dielectric grease to make sure it’s going to stay together and sealed.

Yamaha ATV 

I have a 2003 Big Bear 400 4x4 and it keeps backfiring through the carb. I'm TDC and I cleaned the carb and I adjusted the valves. What am I missing?

John Talley: Alright, when you checked top dead center, was it really lined up like it was supposed to be or was it just a little bit off? Because especially with a machine that has some hours on it, that timing chain is starting to stretch. And of course that’s going to affect your timing and it may be coughing back through the intake. But you’re doing what you should be doing to alleviate that. I’d go back and check the timing one more time to see if that’s the problem.

Want to see more live repair questions answered? See all of Partzilla’s past Live Q&A sessions here.  



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