Partzilla Live Q&A with John Talley – September 18, 2020
John Talley is back again for another Friday edition of Partzilla live Q&A, answering more of your motorcycle and ATV repair questions.
Partzilla Live Q&A Highlights – Honda and Yamaha ATV Repair
I have a 2007 400EX and when I’m in the low RPMs, it seems to bog out. What could be the problem?
John Talley: Is it stock? Have you done anything to it? When was the last time it was run? Has it been sitting up for a while? Because it sounds like this is a transition issue in the carburation when it’s trying to go from idle up to wide-open throttle, sounds like she’s choking down, so I would start looking through the fuel system to make sure all of the jets are cleaned out appropriately.
I have a 2002 400 EX with brand new axle hubs, chain sprockets, rotors, same tire pressure and everything and when I pop a wheelie it pulls hard to the right side. What could it be?
John Talley: Ok. Well that would tell me there has to be an alignment problem, probably on the swingarm. … If it’s a concentric hub, it’s impossible for it to get twisted in one direction or the other. This is a bit of a weird question. You said your tire pressure was the same, are you absolutely certain that the tires have the same aspect ratio, or diameter on the outside? … Just make sure that they’re exactly the same as far as the height to width ratio on them.
Any idea why a 2005 YFZ450 is not sending any power to the bike? I have a new battery, I replaced the key switch and starter solenoid, I cleaned the neutral switch and it doesn’t do anything when I hit the key. Any thoughts?
John Talley: Alright, out of everything you just rattled off, the one thing I didn’t hear you check was the main fuse. So chances are, on the 450 if I remember correctly, there’s a fuse that’s attached that’s part of the same housing that the starter solenoid is in, so take a peek in there with your test light and see if there is voltage across those two points. If that’s fine, the only other thing that I don’t see that you’ve mentioned is the ground wire that actually goes from the battery down to a point on the engine and/or the frame. You want to make sure you’ve got good continuity on that, so check those two things and then get back in touch with us.
I have a 2013 Yamaha Grizzly 550, and I put in a new belt last week and it still seems to be slipping. Is it a clutch problem?
John Talley: On the Grizzly 550, as well as on the 700, I believe they have the same system, and there are actually two separate clutch systems, so to speak. You’ve got the main one on the side which has your primary and secondary sheaves, and that’s the one with the belt in it. … On the opposite side of that enclosure, inside of the engine … there’s actually a centrifugal type of clutch that basically operates like one you’d see on the back of a go-kart. … The Yamaha actually uses a combination of both of those systems to get the machine to move forward. … Because if you just replaced the belt, and there was all kinds of wear left over from the belt that got into the inner workings of the sheave system, it may not be allowing the sheaves to smoothly operate in and out …
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