1996 Foreman 400 Rebuild project-Top end Help!!

[jstatham 27]

17 hours ago, jeepwm69 said:

 

Oh man, I feel you there on being in the wife's view while trying to fix something. 

 

I'm about an hour SW of Memphis, so not really feasible to get it to you.  I have in-laws in Alpharetta but won't be over that way again until April.

 

I'll dig it out and see how the crank looks.  If it doesn't look bad I can pull it and ship it to you, but I wouldn't hold my breath on it being good.

Would you be interested in selling me that bottom end 400 motor you have and I possible meet you in April when your in Alpharetta and pick it up.  Hopefully this motor will make it that long and I can rebuild it and have it ready.

[jeepwm69 7,605]

30 minutes ago, jstatham said:

Would you be interested in selling me that bottom end 400 motor you have and I possible meet you in April when your in Alpharetta and pick it up.  Hopefully this motor will make it that long and I can rebuild it and have it ready.

 

If you're not in a rush to get it, we'll work something out.  I need to check with the wife and see if we're driving or flying in April (newphew's bday is April 1st).  If we fly then we should be coming through there again in late May on the way to South Carolina.

 

I'll shoot you a PM.

[jstatham 27]

2 minutes ago, jeepwm69 said:

 

If you're not in a rush to get it, we'll work something out.  I need to check with the wife and see if we're driving or flying in April (newphew's bday is April 1st).  If we fly then we should be coming through there again in late May on the way to South Carolina.

 

I'll shoot you a PM.

Sounds good.

[jstatham 27]

Hello everyone.  I rolled the dice and used the second replacement Ebay Chinese Jug.  I got a new piston,rings,wristpin,etc and this time the bike looks like a mosquito sprayer.  Anyone have any clue on to what could be wrong.  When I cranked it up the very 1st time it smoked a little. I let it idle about 15 minutes then changed the oil and filter and it seemed to be ok.  I then put everything back together cleaned it up and had it all ready for my daughters Christmas.  I took it for a spin and it started smoking and burning oil like crazy.  I am so upset that she is going to be disappointed. I have been talking to Jeep and thinks I should take the OE jug and the Chinese Jug to a machine shop and see what they say.  One more thing this is a 1996 400 that I put a Top end off a 2002 450 would this cause any issues?  All my research online says it should be ok. Any help will be greatly appreciated I am beyond frustrated.  I have worked my can off on this thing to get it ready.

 

 

 

 

 

[AKATV 822]

Your exhaust MIGHT have oil in it from the previous issue

Take it for a run and see if it burns off or you can pull it and see if it smokes without it

I have done a few rebuilds in the past that I got a little discouraged with and had the same issue and you were having because it was smoking -the muffler became oil contaminated and needed  to burn off

If you were sure of all your other work then I would think this is what is up

It takes a while for the mufflet to become a hot enough to start burning the oil in it so that would make sense why It didn’t smoke it first and then after you took it for a run if the muffler got hot it would’ve smoked burning off the oil

Not saying that’s your problem but it’s a good chance especially if it was smoking before you put a new jug on it

If you determine that it is, you can take it for a good run and burn it out or you can pull the muffler and rinse it with solvent then blow it out real good you want to be careful though doing that -don’t use gasoline or anything flammable like that or it will turn into a bomb

Edited December 24, 2021 by AKATV

[jstatham 27]

That makes sense but if I am burning oil as well then that not the issue right?  I put all new valve seals in it.  Where do you take the muffer loose at the head?  I know 14 years ago when it was parked it was doing the same thing and it only does it when its hot.

[AKATV 822]

The only thing I can think of if it’s not your piston rings and it’s not your valve seals

Is oil in your muffler

Maybe your valve guides are worn and have too much clearance but I wouldn’t think it would smoke like that too much if you had put new valve seals in it

[AKATV 822]

Did you by chance check your piston ring end gap on all the rings in the jug before you installed them in the piston?

No offense - but being a China cheapie they might’ve had the wrong ring set in there or even piston for that matter

Something I learned start doing a long time ago after getting rings that were out of spec -cost me multiple disassembles found it was just easier to check ring and gap prior to assembly 

Edited December 24, 2021 by AKATV

[jstatham 27]

When I get a chance I’ll take the muffler loose at the head and see what happens. Thanks

[jstatham 27]

Just now, AKATV said:

Did you by chance check your piston ring end gap on all the rings in the jug before you installed them in the piston?

No offense - but being a China cheapie they might’ve had the wrong ring set in there or even piston for that matter

No I didn’t. They were the exact same as the one I took off that had the hairline crack.

[AKATV 822]

Id love to see you get this resolved

let us know what you find

I’d be curious at this point to know if you plug is oil fouled or not

[jstatham 27]

At this point I saw its not but I havent checked.  It runs and feels strong.  I hope its just oil in the muffler.  You may have just saved Christmas.  Fingers Crossed.

[AKATV 822]

My fingers crossed too, let us know what you find out 

[jstatham 27]

You got me excited so I went out in the freezing garage and pulled the plug.  It looks good to me. What do you think.

 

[AKATV 822]

Christmas is looking better!

If you were burning oil the plug would not look like that at all

That looks like a pretty clean burning plug to me

Looks like there’s a little  black on there from initial start up

But where it is burning clean on the electrode and not being wet it’s a very good sign

If it was me I’d let the engine come up to temperature and then go do a real good break in run to seat those rings and burn oil out of muffler for about 45 minutes 

You should find that your smoking should diminish if not quit altogether

Edited December 24, 2021 by AKATV

[AKATV 822]

Let us know how you make out 

 

 

Edited December 24, 2021 by AKATV

[Fishfiles 20,145]

I have had it take 3 hours to burn all the oil out the muffler ----

 

it could be the rings need to set  especially since it is a cheap chinese kit ----- let it run for while --------

 

did you lubricate the new valve stem seals ??? ----

 

Is smoke and/ or excessive pressure  coming out the crankcase vent / blow-by hose ?  

[jstatham 27]

Just now, Fishfiles said:

I have had it take 3 hours to burn all the oil out the muffler ----

 

it could be the rings need to set  especially since it is a cheap chinese kit ----- let it run for while --------

 

did you lubricate the new valve stem seals ??? ----

 

Is smoke and/ or excessive pressure  coming out the crankcase vent / blow-by hose ?  

I don't think so but I will check tomorrow. I did lubricate the valve seals.  We have a bunch of family activities planned tomorrow and Christmas but I will post back as soon as I can.  I don't think I am even going to bother taking off the muffler I am just going to go drive it.

[Fishfiles 20,145]

I am hoping it is oil in the muffler 

 

Did you stagger the gaps of the rings on the piston ? 

 

Did you stick the rings into the bore and measure the end gap 

 

Did you check for looseness in the valve guides  ?

 

Are you sure the connecting rod is not bent , did the piston come up flush with the deck ? 

 

 

[jstatham 27]

44 minutes ago, Fishfiles said:

I am hoping it is oil in the muffler 

 

Did you stagger the gaps of the rings on the piston ? 

 

Did you stick the rings into the bore and measure the end gap 

 

Did you check for looseness in the valve guides  ?

 

Are you sure the connecting rod is not bent , did the piston come up flush with the deck ? 

 

 

I did stagger the gaps.  I did not measure the end gap.  Rookie Mistake.

Yes the guides seemed fine.  I followed the 4 wheeler Doctor youtube video on a rebuilt step by step.

Rod were fine and Piston came up flush.

I hope to have time today to mess with it but the wife may have other plans. 

[jeepwm69 7,605]

 Just remember while you’re running it to get it good and hot and break things in to stop periodically and check the oil. 

[jstatham 27]

I had about an hour after everyone left and we took it for a spin. We looked like the mosquito truck for like 2 laps and it finally stopped smoking. I think I am good to go!! Thanks for all the help. If you look at the second video at the end it looks like I need to adjust the tow on the left front. Is there a way to do that?

 

 

[AKATV 822]

17 hours ago, jstatham said:

At this point I saw its not but I havent checked.  It runs and feels strong.  I hope its just oil in the muffler.  You may have just saved Christmas.  Fingers Crossed.

Boy that’s great news I’m glad it worked out!

You can adjust your toe in and toe out by adjusting the tie rod length

The adjustment is in the manual, here’s the link to download it if you need it

https://drive.google.com/drive/folders/15eWwngQ5SdlsIfbgpm5ZJWJYBYx3vJ7s

Merry Christmas to you and your family

AKATV

Edited December 24, 2021 by AKATV

[AKATV 822]

I wanted to ask, and it might just be the photo,but are you running the same diameter size tires on the front and rear? Like both 25 or 26 etc

For some reason it just looked like your rear tires were a lot bigger than your front to me but my eyes are getting old LOL

 you want to be careful if they are different sizes, it’s really hard on the drivetrain and will tear up the gearboxes if you’re on hardpack or pavement especially with a full-time four-wheel-drive

 

Edited December 25, 2021 by AKATV

[jstatham 27]

I am running 25x8-12 in the front and 25x8 10x12 in the rear. I did add a 2 inch lift

Edited December 25, 2021 by jstatham
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