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Anyone know anything about Honda ATV engines?

Russell

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Hey guys!

A few weeks ago I bought myself a Honda Foreman 400 4x4 quad (TRX400FWT) with the 395CC engine to take trail riding while at the lake with the other guys. I have been saving up for a number of years now, and finally found this machine for $4000, thinking I had found my dream rig, within my ability to afford, I bought it.

However, I just got back from my first trip to the lake with it, and managed to wreck the engine already :doah:

Just to be clear, I was not bagging on my machine. I didn't drive it through every waist deep mud hole I could find, infact, I avoided any deep looking hole, and I make sure not to over-rev it while going through muddy terrain that I couldn't avoid. I was being careful simply to avoid what happened anyways -- Carnage.

I am not entirely sure what happened to it, but as I was riding home I noticed that the engine was making an increasingly loud valvetrain noise, and that my quad was burning a bit of oil on acceleration. By the time I got all the way home, my quad was hammering something feirce, and I was already getting quite concerned. I took it to the lake and cleaned it up. Once I fired her back up, it started knocking way worse than before, and was burning oil worse than an old dodge :(

I tried doing a feild valve adjustment to see if I could address the knocking, but it isn't the valves causing all the noise. I then checked the oil and noticed that half of it was gone, and that it was pitch black. It was all there, and was a beautiful golden color when I started that morning. I then figured that maybe I had somehow gotten the oil contaminated, which was causing the rotating assembly bearings to knock, and caused the oil rings to seize up.

I just changed the oil out with some Diesel 10w40 for the extra scrubbing additives, to see if I could loosen it up, but it just smoked all the worse (which I am sure can be mostly attributed to putting the diesel oil in). The bottom end is not as loud as it was, but is still making excessive noise :(

I feel that my only option is rebuilding it. However, having the engine bottom end, transmission, and transfer case all intergrated into one peice, I am quite concerned that it may be far too complicated for me to work on by myself.

Does anyone here have any experience with overhauling these engines? Or am I going to be forced to lay down the cash to get the thing professionally overhauled?

If that is the case, I am not so sure it is worth it :( I may just have to chalk this quad up to yet another foolish dream that starts off appearing to be great, then winding up being yet another dissapointment :(

I guess, I'll start saving again, and maybe in another 5 or 6 years I will be able to afford a newer bike that might not blow up on the first trip :crazy:
 
Im very sorry to hear about your bad experience. Those hondas are built like tanks. I have a foreman 450 and absolutely love it.
Dont give up on the atv dream. They are a lot harder to kill than our trucks are. I am willing to bet that there was something alredy wrong with yours when you got it.

I have owned several atvs over the years and I havn't had to rebuild the engines on any of them, but I have thought about it and after looking at the manuals and diagrams I dont think it would be dificult at all for a mechanically inclined person.

Check out e-bay. I have seen every part for my fourwheler come through there at some point, both in new and used variety. You could always tear your engine down, determine what parts you need and keep an eye out for a good deal on them.

Good luck! I love my quad. Its different than wheeling a truck for sure. and when you do tear them up they are a lot easier to get back home or off the trail.
 
wow normaly hondas are realy reliable i had a 86 four trax and it went through more abuse then anythign i have ever seen and it still ran perfect
well it wouldnt hurt to pull the head off it so u could down in to the motor and help determine how much damage is done to the motor
 
man that sucks
my first honda was big red 200 ATC
thing sat behind a barn for 2 years before i got it
drove it home on the same 2 year old gas
ran like a champ for the 3 years i owned it
 
Well, none of the local repair shops have time to even look at it for at least a week and a half, so I think I may make the foolish mistake of just tearing into it and seeing what happens...

Just figured I'd bump this one more time incase there is someone out there who has rebuilt one of these beasties...
 
Well, I tore it apart, and I'm glad I did!

That engine came apart just as easily, if not easier than any small block Chevy, and before long I found my problem -- Blew the headgasket!

There was a good half cup of oil sitting on top of my piston, lol

My father is on his way home pretty quick with new gaskets and stuff so I can button it up, and see if she is gonna be alright :D

Russ
 
Sweet! Sounds good.

I love my ATV. I've got a 2003 Kawasaki Bayuo 250. I've modified the exhaust and intake a bit and the thing has more power and runs better that stock. The only problem I had with it was blowing a fuse. Replaced it and never had a problem again. Also the nuetral light sensor sticks so I have to figit with the shifter to get the light to come on.

I have pulled out several stumps with it too.
 
Chevy305 said:
Sweet! Sounds good.

I love my ATV. I've got a 2003 Kawasaki Bayuo 250. I've modified the exhaust and intake a bit and the thing has more power and runs better that stock. The only problem I had with it was blowing a fuse. Replaced it and never had a problem again. Also the nuetral light sensor sticks so I have to figit with the shifter to get the light to come on.

I have pulled out several stumps with it too.

I have had two Bayou 220s and have supremely beat the snot out of both of them. I weigh 215lbs and that 220 would propell my fat arse right along.
Loved those things.

Oh I had the same fuse blowing issue with my second one. I wonder if the 250s and 220s use the same electrical system?
 
Robert79K5 said:
I have had two Bayou 220s and have supremely beat the snot out of both of them. I weigh 215lbs and that 220 would propell my fat arse right along.
Loved those things.

Oh I had the same fuse blowing issue with my second one. I wonder if the 250s and 220s use the same electrical system?

I installed a digital tach and it records the max rpm and I pegged it out to over 10,000 rpm :eek1: :p:
 
Well, I replaced the headgasket, and buttoned it all up -- Shes still smoking :(

I really dunno what to think anymore... Either an oil venturi is leaking into the combustion chamber somehow, or I have got a massive oil leak through one of the valve guides :(
 
well the guides are replaceable and the valves are reasonable time for a valve job is the head/block warped my 400EX loves to eat head gaskets maybe it's a Honda thing my buddies 400EX has the same problem
 
This one in specific isn't an 400EX, its actually a 400FWT, which is the workhorse type quad, not a race type quad. They arn't know for blowing headgaskets according to the guys at the dealership.

I'm going to take the head off and take it to a machine shop to be checked for straightness & have the valve guides done. The valve seats, and valves themselves look like they were recently done up.
 

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