Partzilla Live Q&A with John Talley – January 21, 2022

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

Honda ATV repair questions were the main topic of conversation in 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 QA with John Talley 01-21-22

Partzilla Live Q&A Highlights – Honda ATV Maintenance & Repair

Can you tell me why my TRX350 is difficult to change gears, and how do I check or change the gearbox oil?

John Talley: Well, there’s no difference in between your gearbox oil and the rest of the engine oil, as well as your clutch. I’d be curious if you lost a bunch of oil, were you working it really hard? I’ve run into that before and believe it or not, I had that machine with regular oil in it. I went to a semi-synthetic, and the HP oil that comes in the gold bottle does an amazing job, and it might be able to revitalize your gear change smoothness. So I would say go ahead and change the oil quickly and if it looks that bad, if it’s really that broken down in there because it’s doing a lot of work, you may want to change it once with just conventional oil and then go back with the semi-synthetic after that, just to flush it out really well.

I have a Honda Foreman 500 and I just put on new front calipers and brakes. The brakes work well for about two hours and then they lock up and the brake handle can’t be moved. What’s the problem? 

John Talley: It sounds like you addressed the issues going down at the calipers, but I don’t think you addressed the master cylinder up top. So my guess at this point is that the system was dry for a long time, you went and replaced the calipers but you didn’t do anything to the master up top. And it’s probably frozen, so that’s going to be my best guess. Now they do make a rebuild kit which gives you the piston and the seals, and the O-rings to go around the piston itself, if it’s not too corroded on the inside. If it is, then you probably have to replace the whole thing. But odds are it’s just going to be the one piece of equipment that you haven’t dealt with so far, from what I can tell from your question, which is the master cylinder. So open it up and take a peek. 

My Honda Foreman keeps backfiring when I relax off the throttle. Am I correct in thinking it’s a fuel/air mixture screw, or is it a valve needle that needs adjusting? 

John Talley: Do you have an aftermarket exhaust on it? Because if that’s the case, a lot of times an aftermarket exhaust lets you hear more of what’s going on than the stock exhaust would normally cover up. Second, if you’re still running a stock one, did you make any changes to it, and did you go into the carburetor and get it cleaned out or rebuilt? I would think the air/fuel mixture sounds a little bit lean at this point, so I would richen it up about a quarter of a turn. If that still doesn’t do it, go up to a half a turn. Anything beyond that, I’d want to look at the valve needle itself and make sure that you still have the same factory jet in there. If it has been adjusted, bring it back to stock provided you’re at or close to sea level and not like at 8,000 feet or something crazy like that. 

Can you change the main jet on a 400EX without taking it off? 

John Talley: I believe you can … you should be able to loosen up the clamps and just rotate it up to the shifter side and be able to get to your float bowl bolts from there. 

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



Why Partzilla?

Commercial Discounts

Special discounts for companies in the powersports industry


Government Sales

Discounts for federal and most state and municipal agencies