Partzilla Live Q&A with John Talley – February 04, 2022

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

Fuel and air problems for both motorcycles and ATVs came up several times during this edition. 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 02-04-22

Partzilla Live Q&A Highlights – Fuel & Air Problems

I enjoyed watching your video on cleaning the carb of a TRX350. We have a 1987 Honda TRX350 Fourtrax that’s been giving us issues lately with running rich. We’ve cleaned everything out, so do you have any specifics on this issue?

John Talley: So you’re telling me it’s probably running rich at a lower RPM or maybe at idle? Go in and make sure your air-fuel adjustment screw is not too far out. I think the stock setting on the TRX350 is 1¾ turns. That would be the first place I would look, so take a peek there.

The petcock on my Honda 400EX leaks oil into the carb, even with the knob turned off. Time for a new petcock? Also, the gas goes through the hose at the bottom of the carb. Time for a new float valve? 

John Talley: I think you just nailed it. That machine has some years on it, so you’re already pointing in the right direction. The petcock basically has a window where you’ve got two O-rings inside of it, and those O-rings start to break down and most of the time they just stay on all the time. Now as far as your carb overflowing, that’s the float bowl seat or the valve itself is probably cracked or worn out. Hopefully it’s not the seat and you can just replace the shutoff valve itself. If you’re going through the carb and you don’t want to do it piecemeal, I know that Moose makes carb rebuild kits where it’s got all the right gaskets. Because chances are when you open this up, you’re going to create some more problems with gaskets and O-rings that may be sealed right now, but they’re not going to want to reseal when you put it back together. So just be prepared to at least get the gasket or the O-ring for the float bowl when you drop it, because chances are it’s going to need to be replaced if you’re just going to do the needle for the float bowl.  

I dropped my Yamaha R6 as I was getting off it. After I picked it up, it fired right up, but the bike is now sputtering whenever I roll on the throttle. I’m thinking it’s some kind of fuel problem. Your thoughts? 

John Talley: I think you’re exactly right on that. What year R6? Is it carbureted or fuel injected? My bet is that it’s probably fuel injected and if it is, here’s where I would look. Maybe when it went all the way over, it dislodged some trash in the bottom of the tank. Maybe that’s moved over or knocked around or the impact knocked over the fuel pickup. I know there’s a filter on the bottom of it. Let’s start with that. Go ahead and drain most of the fuel, run most of the fuel out of it. Lift up that tank, take a peek at it. Make sure nothing ever got cracked in there during the fall. It shouldn’t have, but I’ve seen crazier things. 

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



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