Smoking like a two stroke!

[TheJaspMan]

How hard is it to repair/replace worn valve guides/seals without removing the engine on a 400ex?

And idea of the best place to get the parts from?

[Westro]

I'm in the same boat and looking for advice.

My father picked up a 1999 Honda 400ex for some work that he did.

I fired it up and it is burning oil. The quad seems fine other than being a little cold blooded.

I was just hoping that it needed rings (oil ring). Is it worth my effort to put in a high compression piston instead of just re-ringing it?

Any thoughts would be great. Also how difficult of a job is it ripping the head off (anything I should watch for). I am coming from a Banshee and 250R (raced D23) background so this will be my first 4 stroke (quad) rip down.

Or is it valves like this post suggests? And where to go for parts?

Thanks
-Westro:D

[TheJaspMan]

After doing some research I am concerned that it's rings since it smokes all the time. We are going to do some further testing and see if that is more the direction we need to be looking.

Originally posted by TheJaspMan
After doing some research I am concerned that it's rings since it smokes all the time. We are going to do some further testing and see if that is more the direction we need to be looking.

bad rings = smoke all the time

bad valve seals = smoke only at startup

sounds like it's time to make that puppy a 416ex....:devil:

[TheJaspMan]

Does it normally happen all the sudden? Or is there a chance it has been over filled with oil?

It was not smoking at all. Then started immediatly following an oil change.

[Westro]

My fathers smokes all the time.

So what is a 416 kit going for? I have a feeling that he is looking at stopping the oil consumption, not looking for the power increase.

Wiseco piston and ring set or is there another manufacture that you recomend. I would assume also check the valves. So for a hundred bucks he could get it back to a "stock" configuration.

Is there any suprises that I should be made awhere of before I pull the head?

Thanks

[Cody_300ex]

Originally posted by Westro
I'm in the same boat and looking for advice.

My father picked up a 1999 Honda 400ex for some work that he did.

I fired it up and it is burning oil. The quad seems fine other than being a little cold blooded.

I was just hoping that it needed rings (oil ring). Is it worth my effort to put in a high compression piston instead of just re-ringing it?

Any thoughts would be great. Also how difficult of a job is it ripping the head off (anything I should watch for). I am coming from a Banshee and 250R (raced D23) background so this will be my first 4 stroke (quad) rip down.

Or is it valves like this post suggests? And where to go for parts?

Thanks
-Westro:D

Hey man im only 12 (13 tommrow) and i did a top end on my 300ex on my own.

[TheJaspMan]

OK scratch the valves and rings.

Leak down test is fine. As is the compression test. Come to find out one of the needles must have gotten struck by dirt. The end is a little hooked and the carb needs cleaning.

[Quad Dude]

when u take off the cam watch out for the decopression spring and needle without it u wil never get it started. talking from experince here so be carefull other that its not hard really