Partzilla Live Q&A with John Talley – August 21, 2020

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

While many questions were asked about everything from Suzuki to Kawasaki and Honda powersports vehicles, Yamaha powersports vehicle repair questions once again were popular this time around. Check out 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 with John Talley

Partzilla Live Q&A Highlights – Yamaha ATV & Motorcycle Repair Questions

Yamaha ATV Exhaust/Valves

I have a 2016 YFZ450R with a power commander 5 and a full DASA exhaust. It seems to backfire on deceleration and miss at low rpms. I am wondering if it could need a valve adjustment.

John Talley: Those two things that you’re talking about are usually not indicative of the valves being out of whack. Maybe the hesitation at low RPMs, I might be able to buy that one. But as far as your backfire on deceleration, you’re probably hearing that A. because you have the commander in there but B., any aftermarket exhaust usually is more open than an OEM one, and the OEM one is designed to pretty much mask most of these sounds that become apparent when you put a free-flowing exhaust on there, which the DASA system is. It was probably making that backfiring noise when you had your stock one on there, but now you can hear it because you have the different exhaust. And beyond that, it never hurts to look at your valves and make sure they’re in check. Over time, they usually start to tighten up and then you need to get them back into spec because if they get too tight, then it’s going to do two things. It’s going to make it really hard to start, unpredictable off the low end throttle, and it’s going to prematurely wear your cam because it’s working a little bit harder than it should. 

I have a 2017 Raptor 700 and I went through a deep puddle, and the exhaust and intake went underwater and a bit of water came out of the drain. Now it has a slower rev. Clogged filter?

John Talley: Yeah, if you went all the way under like that, it’s time to part the machine and open it up. Open up your air intake, take out your filter, clean out the intake that’s going into your throttle body, go ahead and drain your oil. … I would probably even go through the fuel system as well, even though it’s a closed system on the 2017. It’s just a matter of taking everything down, and do it soon, because you’ve evidently got water in places it’s not supposed to be. And the longer it stays there, the more damage it’s going to do. Go ahead and break it down and do it quickly, because chances are you can just clean it back up and get some fresh oil, clean out your intake and then you’re going to be good to go. On that one I believe the filter is reusable on the intake, so it shouldn’t be that big of a deal.  

Yamaha Motorcycle Spark Plugs

So what would cause an ‘04 R6 to be killing the plugs?

John Talley: Typically, when you say it’s killing the plugs, that it’s running so rich that it’s fowling them out? My question would be, what programmer do you have on it? What’s your intake; what’s your exhaust; does it have a programmer? Which app are you running, because it sounds like it’s running too rich, and it’s just wearing out or sitting up the plugs way too quickly. 

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


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