[hondanutz]

The motor has issues, but the valves, rocker arms and push rods oil from the top down. Do you have the service manual? If not, PM me an email address and I will see if I can attach a PDF copy and email it to you.

It is not uncommon to see the ring down the side of the piston - part of it depends on the engine design.

I got the head, with new valves in it, back on the quad. I fired it up and still it rattles like crazy. Here is what happened to this thing, I think.
Before I put the head on, I drained the oil. Not much came out. 1/2 quart, maybe. Changed the oil filter ( the old one was in backwards :frown2. I put 2.5 quarts in it and I noticed it leaking. :frown2: I think it's coming from the shifter shaft. So, I think the oil leaked out enough to get below the oil seal on the shifter. When I got it, the first thing, like always is check the oil. Didn't show in the dip stick. I put about a cup in it and it was just on the tip of the dip stick. I figured that was enough just to see if it would start. Now, fast forward to today. I cleaned the oil passages in the valve cover by blowing brake cleaner thru them. They all seemed to flow fine. But, the exhaust valve seems to get more oil than the intake and that seems like where the noise is coming from. The intake is getting oil, just not as much as the other one. I wonder if the noise is due to some engine damage due to low oil. It never leaked a drop while sitting in my garage, so whatever leaked out did so somewhere else.

 

[Here 2 help]

I don't know how the oil filter could have been in backwards unless the spring was missing, but having the filter in backwards just means the oil was circulating unfiltered.

As long as the oil was touching the dipstick, it had plenty of oil for starting the motor.

I would be more inclined to think the engine was rebuilt by a novice mechanic who may have installed a standard sized piston in an over-sized bore. It's one of the reasons I won't buy a used machine if the seller says he worked on it himself. And if he says he had work done to it, I want to know who did the work, what was done to it and why. I'm an asshole - I know it and I'm comfortable with it.

Minor oil leaks usually do not compromise engine integrity. As long as there was a seal on the shift shaft, it almost could not leak enough to cause engine damage as long as the oil was checked before the engine was run for any extended length of time.

 

[hondanutz]

I don't know how the oil filter could have been in backwards unless the spring was missing, but having the filter in backwards just means the oil was circulating unfiltered.

As long as the oil was touching the dipstick, it had plenty of oil for starting the motor.

I would be more inclined to think the engine was rebuilt by a novice mechanic who may have installed a standard sized piston in an over-sized bore. It's one of the reasons I won't buy a used machine if the seller says he worked on it himself. And if he says he had work done to it, I want to know who did the work, what was done to it and why. I'm an asshole - I know it and I'm comfortable with it.

Minor oil leaks usually do not compromise engine integrity. As long as there was a seal on the shift shaft, it almost could not leak enough to cause engine damage as long as the oil was checked before the engine was run for any extended length of time./QUOTE]

The filter was definitley in backwards and the spring is there. Idk how that happens.

But I checked the amount of oil that came out and it is exactly 1/2 quart. I remember when I started it that the ex valve was getting oil, so you're probably right about there be being just enough. I pulled the belly pan and it is for sure leaking around the shift shaft. No big deal there. But, I don't what I should do about the all the racket? Should I pull the head and cylinder and check it out. Maybe measure the piston and cylinder? Hey what about where the pushrods ride on the cam? I know in a car engine they have hydraulic lifters than can be troublesome at times. Does this thing have something similar? Can I re-use the head gasket if I take it apart?

 

[Here 2 help]

Finding the noise is a process of elimination - if the valves are adjusted correctly, then the source of the noise is deeper. The push rods set into lifter buckets that contact the camshaft. If the lifter buckets were the source of the noise it would be more of a scratchy or raspy noise. I have a feeling the noise is from the piston or crankshaft. It is not recommended to reuse the head gasket, but if you do and it doesn't seal, you'll just have to install a new one later.

 

[hondanutz]

Finding the noise is a process of elimination - if the valves are adjusted correctly, then the source of the noise is deeper. The push rods set into lifter buckets that contact the camshaft. If the lifter buckets were the source of the noise it would be more of a scratchy or raspy noise. I have a feeling the noise is from the piston or crankshaft. It is not recommended to reuse the head gasket, but if you do and it doesn't seal, you'll just have to install a new one later.

YOu called it. The piston, wrist pin and cylinder are trash! I knew I shoulda pulled the cylinder off when I had the head off the first time. Oh, well. Live and learn.
The big end of the con rod seems o.k. NO play in it. How can I have at least some assurance that the mains are ok before I do the top end and put it back together?

 

[Here 2 help]

The main bearings are ball bearings and rarely go bad - when they do, the engine runs fine but growls - if the crank turns freely, the mains are usually fine

I would be more concerned with the piston pin - if it seizes to the small end of the rod, the crank needs to be replaced - if the crank gets replaced, so do the main bearings - just a matter of a complete vs half a job

 

[hondanutz]

The main bearings are ball bearings and rarely go bad - when they do, the engine runs fine but growls - if the crank turns freely, the mains are usually fine

I would be more concerned with the piston pin - if it seizes to the small end of the rod, the crank needs to be replaced - if the crank gets replaced, so do the main bearings - just a matter of a complete vs half a job

Ya, I just talked to the Honda shop about boring the cylinder( they don't do that anymore) but the dude was asking me about the con rod. The piston wobbles back and forth, alot, on the wrist pin. I think the small end of the rod is toast. So, that pretty much seals the deal for me. I'm done with this thing. Wanna buy it? :wink2:
Parts may be on ebay soon!

 

[Here 2 help]

Wanna buy it?

I might have been interested if you were closer to me.

 

[hondanutz]

Wanna buy it?

I might have been interested if you were closer to me.

I haven't had any luck on selling/parting this quad out. Soooooo, I'm gonna pull the engine and see about fixing it myself. I think in an earlier post you mentioned that the crank has ball bearings and are hard to damage. With that in mind, I'm hoping that I can replace the rod and bore the cylinder and new piston. I think this quad is worth fixing. I know you sent me a manual,but, I didn't save it. I don't remember if you emailed it? I'll look, but if I don't find it, I might have to ask for it again. I'll save it this time! :smile2:

Oh, and the trx450 that had the stripped spark plug hole is up and running. I got the time-sert kit and fixed it. That's neat little invention!

Edit: I was just looking at the parts. Looks like the crank/rod come in one assembly.

 

[Joshtrx]

12mm dia - 3/4 reach

Do you know the thread pitch and depth needed for a 2005 trx400ex spark plug hole?
Threads are striped on my engine.

 

[Here 2 help]

12mm - 1.25 threads per millimeter x 3/4" or 19mm depth