Honda fourtrax issues

[Cowman]

I have run into an issue with my Honda fourtrax that I purchased new in '97. It has been a very reliable ATV and has been kept in a building out of the weather most of its life. Recently, I cranked it and it sounded like there was no exhaust noise. Sure enough there was very little exhaust coming out the end of the muffler. Not surprisingly, the engine was very weak. I'm assuming something is blocking the exhaust, but what could it be? Anyone have any thoughts or experience here?

 

[Admin]

 

[Backwoods]

I have run into an issue with my Honda fourtrax that I purchased new in '97. It has been a very reliable ATV and has been kept in a building out of the weather most of its life. Recently, I cranked it and it sounded like there was no exhaust noise. Sure enough there was very little exhaust coming out the end of the muffler. Not surprisingly, the engine was very weak. I'm assuming something is blocking the exhaust, but what could it be? Anyone have any thoughts or experience here?

I had dirt dobbers stop one up years ago. Mouse ?

 

[ChadD]

I have run into an issue with my Honda fourtrax that I purchased new in '97. It has been a very reliable ATV and has been kept in a building out of the weather most of its life. Recently, I cranked it and it sounded like there was no exhaust noise. Sure enough there was very little exhaust coming out the end of the muffler. Not surprisingly, the engine was very weak. I'm assuming something is blocking the exhaust, but what could it be? Anyone have any thoughts or experience here?

P.O.I.D.H
#NTC

Does it have compression? Maybe bad rings?

 

[Cowman]

I had dirt dobbers stop one up years ago. Mouse ?

You may have something there. The engine was running fine, then after sitting up for several weeks, this happened upon cranking it. We have a good supply of the dirt dobbers in our area...they build in just about any opeing or hole that sits still long enough. I will investigate that, as it would explain all the symptoms.

P.O.I.D.H
#NTC

Does it have compression? Maybe bad rings?

Enine cranks and runs fine, uses no oil. As described above, this happened suddenly while it was sitting idle for few weeks. Ran fine upon killing it, then a few weeks later this happened. No exhaust noise...so quite you can hear the valve rockers, etc. But no power upon applying throttle. I'm pretty sure it's a stopped up exhaust system. Just not sure of the cause.

Thanks to both of you for your responses.

 

[ChadD]

You may have something there. The engine was running fine, then after sitting up for several weeks, this happened upon cranking it. We have a good supply of the dirt dobbers in our area...they build in just about any opeing or hole that sits still long enough. I will investigate that, as it would explain all the symptoms.

Enine cranks and runs fine, uses no oil. As described above, this happened suddenly while it was sitting idle for few weeks. Ran fine upon killing it, then a few weeks later this happened. No exhaust noise...so quite you can hear the valve rockers, etc. But no power upon applying throttle. I'm pretty sure it's a stopped up exhaust system. Just not sure of the cause.

Thanks to both of you for your responses.

I would check for mice. If they built a nest in muffler you might want to check air cleaner and wiring also.

Good luck and I'm still waiting for pictures 😉

 

[Cowman]

Checked the muffler for mice nests and mud daubber nests...nothing that I can detect or see. Something else appears to be blocking the exhaust previous to the baffles as far as I can tell.

 

[Backwoods]

@Hello_Darkness is a good Honda tech. He will see this and respond tomorrow hopefully.

 

[Hello_Darkness]

Does the engine sound like it's spinning faster during cranking, like it doesn't have compression?

Does pulling the recoil started feel right?

 

[Cowman]

I haven't tried the kick start, but will give that a shot tomorrow. One thought: as I mentioned the exhaust noise is greatly reduced since there is very little exhaust, so engine noise is more noticable. It does sound like a valve rocker is loose. Am wondering about the possibility of the exhaust valve being significantly out of adjustment and not opening very much whether that could account for lack of much exhaust and not much engine power. Before I attempt to remove the muffler I think I will check the valves.

The engine cranks and idles just fine.

 

[Hello_Darkness]

I haven't tried the kick start, but will give that a shot tomorrow. One thought: as I mentioned the exhaust noise is greatly reduced since there is very little exhaust, so engine noise is more noticable. It does sound like a valve adjustment is loose. Am wondering about the possibility of the exhaust valve being significantly out of adjustment and not opening very much whether that could account for lack of much exhaust and not much engine power. Before I attempt to remove the muffler I think I will check the valves.

If it's that significant, it might have hung open a valve.

I originally thought you were talking about a 400 Foreman for some reason, but I see it's a 300.

Are you sure the manual decompression release on the head isn't engaged/stuck?

 

[toddvdh]

It’s Chads picture that is a 300. Not sure what the op has.

The manual decompression could be stuck. I never thought of that.

 

[Cowman]

Sorry, I thought I put that in my OP....it is a 300. The first thing I checked was the compression release...it doesn't seem to be stuck. I'm going to pull the valve cover and check the valves and go from there.

Not an emergency situation as I do most of my riding in the Pioneer 1000. The 300 has been relagated to mostly doing some spot spraying for weeds/brush around the farm, etc. with an occasional grandkid riding it. But I would like to get it back up and going again.

 

[Hello_Darkness]

Sorry, I thought I put that in my OP....it is a 300. The first thing I checked was the compression release...it doesn't seem to be stuck. I'm going to pull the valve cover and check the valves and go from there.

Not an emergency situation as I do most of my riding in the Pioneer 1000. The 300 has been relagated to mostly doing some spot spraying for weeds/brush around the farm, etc. with an occasional grandkid riding it. But I would like to get it back up and going again.

You can check valves on that unit without removing the whole cover, just the caps.

The starter clutches are known to go bad as well on those could be slipping.

 

[ChadD]

Sorry, I thought I put that in my OP....it is a 300. The first thing I checked was the compression release...it doesn't seem to be stuck. I'm going to pull the valve cover and check the valves and go from there.

Not an emergency situation as I do most of my riding in the Pioneer 1000. The 300 has been relagated to mostly doing some spot spraying for weeds/brush around the farm, etc. with an occasional grandkid riding it. But I would like to get it back up and going again.

Still waiting for pictures 📸👀🙄🤣

 

[Cowman]

Sorry about the pics...it's just a 27 year old 300 tan colored four-trax that needs a good washing at the moment. Stock condition but with new tires. It's been a good vehicle with no problems and usually cranks after the engine turns over one time.

Hello-Darkness, I did pull the cap off the exhaust valve since it was the easiest to get to. There may be a little slack in the valve adjustment but not enough to cause these issues. The compression release is working just fine in that it slightly opens the valve and then closes it when returned to the normal position.

I checked the air intake for blockages and nothing there. As I said, it cranks just fine with no indication of starter problems and will run but has reduced power and very little exhaust coming out the tail pipe. And as I said, the exhaust is unusually quiet...what one would expect if something in it is blocked I suppose. I am, at this point, leaning towards some sort of blockage in the forward portion of the muffler as I can see into the back of the muffler to where the baffles are. I removed the carbon cleanout plug from the bottom back of the muffler but no significant exhaust coming out there either.

I am somewhat afraid to try to remove the exhaust header from the engine as the two studs look to be somewhat corroded...and I do not want to have to deal with broken exhaust pipe studs if I can avoid it. Thinking about just cutting the muffler off where it joins the exhaust pipe and then welding it back if necessary. This exhaust pipe and muffler are a one piece assembly right?

Guys, I very much appreciate your time and help...

 

[DRZRon1]

Sorry about the pics...it's just a 27 year old 300 tan colored four-trax that needs a good washing at the moment. Stock condition but with new tires. It's been a good vehicle with no problems and usually cranks after the engine turns over one time.

Hello-Darkness, I did pull the cap off the exhaust valve since it was the easiest to get to. There may be a little slack in the valve adjustment but not enough to cause these issues. The compression release is working just fine in that it slightly opens the valve and then closes it when returned to the normal position.

I checked the air intake for blockages and nothing there. As I said, it cranks just fine with no indication of starter problems and will run but has reduced power and very little exhaust coming out the tail pipe. And as I said, the exhaust is unusually quiet...what one would expect if something in it is blocked I suppose. I am, at this point, leaning towards some sort of blockage in the forward portion of the muffler as I can see into the back of the muffler to where the baffles are. I removed the carbon cleanout plug from the bottom back of the muffler but no significant exhaust coming out there either.

I am somewhat afraid to try to remove the exhaust header from the engine as the two studs look to be somewhat corroded...and I do not want to have to deal with broken exhaust pipe studs if I can avoid it. Thinking about just cutting the muffler off where it joins the exhaust pipe and then welding it back if necessary. This exhaust pipe and muffler are a one piece assembly right?

Guys, I very much appreciate your time and help...

u have a way to measure temp with a probe, meat probe, spray bottle with water, temp gun?



if u r blocked somewhere in the header should be able to tell

or run it with lites out - if u have a blockage the header leaving the engine shouldj get red hot ?

 

[Cowman]

After checking everything else I could think of, I finally cut the muffler off the exhaust pipe...the exhaust pipe and muffler are one piece. The issue is that the muffler is blocked on the inside. So I am going to most likely look for a muffler to replace it.