1998 Kawasaki 400 bayou 4x4 input

[Frank Angerano]

Hey QC people, hope everyone’s doing well.  I just picked up a 1998 bayou 400 4x4 in great condition for a song and a dance! Good deal. It has been sitting since 2014. Original owner!!! Anyway he put the bike away in 2014 and has not touched it. He said the head has a little tick that’s about it. 

I love the way the bike looks and it seems like a well built bike. 

Im posting because I’m curious if anyone has any input on this bike? Good bad ? It’s in amazing condition but the fuel was left in it and gas peacock turned on of course so a carb rebuild is in order and some really stanky gas In the tank.  But any input on this bike would be appreciated! Thanks. 

[quadmaniac]

My buddy had a Kawasaki Bayou what I thought was a 300 but not sure, it definitely wasn't the 220. Couldn't kill that thing, went through mud, water, all over the place. Nice quad!

[Frank Angerano]

Thanks @quadmaniac I ripped into the carb it was packed with solidified gas and the float and bowl needle were jammed in place. After a good soaking and rebuild kit I reinstalled it and fired up the bike. I noticed a little oil coming from the top of the head but no ticking, I did not have  much time to look into it. I think I’m going to rip the plastics off and tear the top end down for an inspection and fresh gaskets and seals. I seen a lot of posts about this engine on you tube with upper end problems with cam issues where the cam is seated. Hopefully this is a simple gasket problem and nothing more. Thanks for the input. 

[Frank Angerano]

After hearing this bike run for a while I def hear something in the head. It’s not a tick but a slight knock.  So I tore into it and found that the journals that support the cam on the opposite side of the timing chain are worn leaving a little wiggle room for the cam to kinda flop around.  

Im looking into a semi new valve body and see a lot of used ones in good condition for about 200 bucks. My question is am I wasting my time ? Is this normal ? Is there another fix ? Should I ride it out ? Is it going to tear the top end apart ? 

@Ajmboy @davefrombc any ideas ?

[Ajmboy]

Nice job diagnosing and tearing into into it @Frank Angerano! How was the oil because there may have been a lubrication issue if they wore out that bad. I'm not sure how bad it is or the noise but as the quad gets older things wear and depending how it was maintained and ridden will correlate to what conditions the internals are and what noises it starts to make.  So if oil was neglected maybe it caused an issue. I've seen fixes out there with some sort of goob but I don;t know how that works. You can probably ride it the way it is but depending what you spent on the quad and the fact that you have it apart, I would look into maybe replacing the head with a used unit but before you buy it make sure the cover is off so you can inspect. Like this ebay listing for $188 https://www.ebay.com/itm/Kawasaki-Bayou-400-98-99-Engine-Cylinder-Head-15871/292413774392?fits=Make%3AKawasaki|Model%3ABayou+400&epid=1923102086&hash=item4415381a38:g:40QAAOSwItJaYKdu&vxp=mtr

There's another one for $150 OBO, but who knows what it looks like inside: https://www.ebay.com/itm/Cylinder-Head-11008-5006-Kawasaki-1996-Bayou-400-ATV-4x4/192432356986?epid=1424636978&hash=item2ccddcbe7a:g:ZbgAAOSwU91aYnAm&vxp=mtr

You might want to take your head to a machine shop and see if they have any type of fixes. If it's not that bad, just inspect your oil passages, change the oil and ride it the way it is. 😁

[Frank Angerano]

Thanks @Ajmboy for getting back to me. So the oil was good. The problem I think was I found a leak on the halve adjustment cap there is an o ring or gasket if you will, that was missing and silicone put in there as a fix. Previous owner said he ran it low when he found the leak on the top end but thought there was no damage. 

So anyway the journal is scored, not terribly but it’s noticeable. So I’m assuming that was causing the knock up top. Oil pressure is good and the new o ring/gasket  is in place. And the bike is running great. But when you rev it up i can hear it. So having said all that I reached out to that eBay link that you sent and asked for some pics of that head assembly esp the journals. Thanks a million.

This bike has never been touched by anyone. It’s orignal and completely in tact. So that’s why I like it. The gears shift like its right from the dealer.  The problem with this bike is the first gear is a SL super low gear. Makes for a very high rpm I’m thinking that’s where a lot of the damage comes from. So to sum it up I think I’m going to change the top end If the one that’s on line it’s in good condition and go from there. I have reached out to a few machine shops that do this kind of work and looking into both options. Only because I got the bike for $300 bucks and it’s in amazing condition. 

Keep you posted. Thanks 

[Frank Angerano]

Hey hay hay so I’ve recieved the new/used head and to my surprise it’s in very very good condition with no scoring whatsoever. The person that had the head threw in a bunch of additional parts, bolts, cam sensors etc even a rear rack!!!!!! Great vendor tg! Going to tear into this thing tomorrow and god willing have it ready to fire 🔥 on Sunday. It’s been a little while since I tore into an engine like this and I’m looking forward to it. Quick question... the new gaskets, in the past (long time ago) I’ve always used a schilack on each side of the gasket right before I set it in place, good bad? Any recommendations on this anyone ?

[Frank Angerano]

So take a look at this rocker arm. The waves are unreal. Also look at the cam seats (journals). 

Never seen anything like the waves on rockers like this. Any idea as to why ? @Ajmboy 

[Frank Angerano]

[Frank Angerano]

[Frank Angerano]

So my question is now....that I have the head off and looking at the top of the poston I decisded to take the cylinder off and inspect the crank and piston.  It looks great but I’m wondering if I should put a new piston and rings in?? I have it apart and the new head/valve assembly are here.  Just not sure what to do. @Ajmboy @davefrombc What do you think? 

[davefrombc]

Hard for me to  call  from afar.  Does the  cylinder  bore  look  good or is it  showing visible wear?. Your  photo  of the piston  looks  like the  piston and rings  are  in  good  shape. Depends on price  and  budget,  but if the  cylinder  bore,  piston  and rings all  look  good,  I'd tend to  go  with them ..  any  obvious excessive  wear or scoring  on them  and  I'd  go  for  a re-bore , new  piston  and rings since you're that  deep  into the motor.

 The  outer  journal on the  rocker shaft  looks like  it  may  have been  put together  without being  tightened down  properly  and  the subsequent   loose  bore  allowed the  outer journal of the  rocker  to   slap  around  and slop it  out . Can't  say  why  the  rocker developed the  wavy  pattern. Wild guess is  it  may  possibly  be  because  of the slopped out  journal  allowing the  rocker to   follow  an  uneven pattern  on the  cam.  How  does  the  cam  look?

[Frank Angerano]

Thanks @davefrombc for getting back to me. The cylinder looks good and piston is ok. Usual wear nothing out of the ordinary.  I was just thinking why not throw a new stock piston in since it’s opened up. As for the head goes I heard a small knock when the revs came up.  After removing the head I noticed the rocker arms and the journals were beat up pretty bad plus that waving pattern so I assuming that’s where the knock was coming from.  The cam looks discolored from heat. The lobes have scorch marks. I decided to pull the cylinder only to check the piston and the main bearings/connecting rod which all looks good. No metal shavings of any kind  in the oil. The crank and main bering feel good with no play. 

So do I put it back together with the orignal piston? The head I got for it although used is in great shape. The gasket set that i have also have valve seals. What’s your take on that since the heads out? Change them ? 

[Ajmboy]

I would agree with @davefrombc and depends on your budget. I have a habit of throwing parts at everything if I'm in there where fixing my atv, car, or oil burner! Great pictures BTW, not sure what is causing scoring like that and I would assume it's friction/oil issue/vibration at some point. 

[davefrombc]

I'd likely go with the  original  piston and rings  only  because of   cost ,  but  if you  can  get  new  at a reasonable price  that would be   a good option ..  You should  break  the  glaze in the  bore if you  go  new  piston  and rings  so that the rings  can seat  in properly.  Measure the  bore to see if it  is  on spec  before going that way though.  Sorry ,  I can't  make the choice for you.   LOL...    I'm  a   cheap  retired old  fart.  Gotta  weigh  cost /  benefit  in all  I  do .

 

[Frank Angerano]

Awesome replies thanks for the help @davefrombc and @Ajmboy I think I’m going to stay with the orignal piston only bc the compression was great and no smoking or oil blow by. Also your recommendations. What’s your thoughts on the valve seals on the replacement head ? Put in the new seals or not? I have them but honestly I have never done them before.  I’m not sure how this head performed on the last engine. 

[davefrombc]

Can't  help  you there  Frank.  I  haven't had to  do them  on an  ATV  either. I would imagine they'd be  like on a  car  engine, only smaller and  not really  hard to  do    if  you  can  compress the  springs   to  remove the  keepers without having  springs  and  keepers  flying all  around  the  room  (  done that    with  a  car  head    LOL ) Fun finding the  pieces .

 

[Frank Angerano]

I hear ya. I just took a look it seems pretty simple.  I ordered a spring compressor form amazon just now. Be here tomorrow and get it done.   Thanks again pal for all the help. 

[Frank Angerano]

Flying pieces for sure!! Thank god I had the old head to practice on!  Valve seals done. It was not that bad, I made a jig to press the valve down and changes them out. The inside of the valve chambers were in great shape I attached a pic.  I feel batter knowing the seals are done.  It would be a shame to have a bad seal after doing this.  New head and cleaned up cylinder is ready to go in.  Maybe later tonight.  I posted a pic of the old cam as well. Super discolored and def scorched.  

[Frank Angerano]

Halfway there ! Coming back together! Thank god for beer and country music! 

 

Edited February 6, 2018 by Frank Angerano
Forgot the pic!

[Frank Angerano]

All done and no knock! Tg. 

 

[Frank Angerano]

Thanks @Ajmboy and @davefrombc for the assistance. 

2A329187-60FF-413A-81B6-2DC3CF0CD0B3.MOV

[davefrombc]

Glad to  be   of  a bit  of  help.  Really  all  I  did  was offer opinions. Looks like you  did a  great job..  Enjoy riding your  new to you rig.

Edited February 6, 2018 by davefrombc

[Frank Angerano]

Thanks brother.  

[Achilles]

Hey I know this was posted some time ago but I was enjoying following the progress.  How did it work out in the end?

[Frank Angerano]

Worked out perfect! Bike runs like new.  This happenes to be on of the most powerful bikes I own.  It’s amazing how theses parts were  still available.  

But in the end 100% worth it and a ton of fun ripping it apart and putting back together.  

Thanks for asking!

[Achilles]

That's great to hear.  I have a 98 Bayou 300 4x4.  Trying to go through it now to see what I need to get her in good shape for work around the property,  Nice to know parts are available still

[Frank Angerano]

There are parts ! I have a guy in PA he is great.  He has so many parts etc. if you need anything I will shoot you his info. He ships all over!

[Achilles]

Yes that would be great, thanks Frank!  I am in WA so glad to hear he ships all over