Honda TRX400 Oil Service Questions & Answers

The TRX400 is quite the popular Honda ATV model, and when our resident powersports expert John Talley does his weekly live Q&A sessions, questions about its repair and maintenance come up quite often. 

John answers our viewers' questions live every Friday at 3pm Eastern on our YouTube channel, and in this session the ever-popular Honda TRX 400 came up several times. Here are John's answers to a couple of questions related to TRX400 oil change services.

Honda TRX400 oil service

Honda TRX400 Oil Change Q&A

I did an oil change on my ’07 400Ex and when reinstalling the oil filter cover, the long bolt wouldn’t tighten up and it snapped. I was using a 3/8th torque wrench and set it to 7 foot-pounds. What should I do?

John Talley: First question I want to ask is, what torque wrench was it? The one that I use is a high quality one, but if you let it sit for too long, it’ll shut off and give you no indication that that has happened until you start ranking down and torqueing it in. And your internal torque wrench is saying “stop stop stop!” but it’s just not beeping. So I’d be curious to know if it turned off by chance, but to answer your question, now what do you do? … I’m not a big fan of helicoils. What I do like using are time-serts, and I’m afraid that’s where you’re going to have to get to. You’re going to have to get down to wherever those threads are, drill it out and then get a time-sert in there. 

Watch the video above to see how to do an oil and filter change on a Honda TRX400.

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Watch the video below for tips on how to extract broken bolts.

I have a 2005 400EX and I’m constantly putting oil in it. It doesn’t leak, and it only smokes a little bit when revved. Any ideas?

John Talley: Have you done a compression test on it yet? I’d like to know what the numbers are in there. When you’re saying that it burns the oil when you’ve really given it a lot of juice, that typically indicates you’re going to have a problem with your valves. Maybe the seals are worn, maybe the guides are a little bit worn, and it’s letting oil seep past into the combustion chamber. But without knowing the numbers first, I’d be afraid to point you in one direction or another. So if you would, pick up a compression tester, do a test, and let me know. If the compression test is inconclusive, before you go pulling it apart, if we really think it’s losing it somewhere either at the head or the piston rings, you may want to consider doing a leakdown test. I’m not sure we did a leakdown test on that particular model, but I’m fairly certain that we did an ATV compression test … 

Watch the video above to see how to do a compression test on an ATV.

Want to see more live repair questions answered? See more motorcycle and ATV questions answered here.  



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