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jstatham

1996 Foreman 400 Rebuild project-Top end Help!!

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Ok must be my eyes -lol, the rears looked 2 inches bigger to me

glad you got it all sorted out

Happy Holidays

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Hello everyone.  My daughter is ripping and roaring all over the place.  She is on cloud 9.  Thanks again for all your help.  Does anyone know where this bolt goes?  I cant find it on the parts diagram but it came off sometime when I broke it down from the seat to gas tank area.

 

 

bolt.jpg

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Merry Christmas to you and your family I’m glad to hear it !

That is a muffler bolt and washer that bolts your muffler to the rear frame rail, there should be two of them

Sometimes it’s a trick to get them to catch into the nut portion on the backside, sometimes you can slip something up in the frame rail to hold the backside nut piece steady while  you screw the bolt in

Edited by AKATV

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I guess that's why I couldn't fine the Muffler bolts.  HAHA!!  The strange thing is there was only 1 when I broke it down.  I just found some bolts with the right thread and used them.

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Glad the smoke went away --------   

 

I see tires that run taller , my wife's 300 has 27s all around and the rears look so much taller than the fronts , rears are 12 wide  and the fronts are like 9 wide , the width of the rims can have something to do with it , but sometimes I feel that some tires ride tall or short 

fullsizeoutput_497.jpeg

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14 minutes ago, jstatham said:

Looks awesome!!

Thanks  -----  don't those rear 27s look taller / bigger than the front 27s 

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Not 100% but I think I kind of heard this when you were running it early on 

it kind of sounds to me like your timing chain tensioner is “bouncing”

They have a habit of going bad and the ratchet system doesn’t lock like it’s supposed to and causes the tensioner to actually bounce in and out and timing chain slaps too

Not 100% but it’s easy enough to pull the front cover and you can start it real quick and run it and see if it’s bouncing or what shape its in

If it’s smoking it’s got to be your rings or valve seals not sealing up

-check that plug and see if it’s burning oil too

Edited by AKATV

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Ok I pulled the plug and to me it looks ok so does that mean the valves aren't sealing?  I put new valve seals on it. Should I try adjusting them? I am about to the point to pulling the engine rebuilding the crank and have the OE jug bored and new shindy piston rings, Cam Chain and tensioner.  If I do rebuild am I missing anything else.  I really don't want to go this route but I might not have a choice.  Where do you get your parts? and should I stick with Honda OE chain?  They are 4 times the price of the aftermarket. Any help will be greatly appreciated.

Sorry to ramble but what would be your next steps?

 

 

https://youtube.com/shorts/KHB9tWs9VXo?feature=share

 

 

plug 2.jpg

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14 hours ago, jstatham said:

Ok I pulled the plug and to me it looks ok so does that mean the valves aren't sealing?  I put new valve seals on it. Should I try adjusting them? I am about to the point to pulling the engine rebuilding the crank and have the OE jug bored and new shindy piston rings, Cam Chain and tensioner.  If I do rebuild am I missing anything else.  I really don't want to go this route but I might not have a choice.  Where do you get your parts? and should I stick with Honda OE chain?  They are 4 times the price of the aftermarket. Any help will be greatly appreciated.

Sorry to ramble but what would be your next steps?

 

 

https://youtube.com/shorts/KHB9tWs9VXo?feature=share

 

 

plug 2.jpg

DID or OEM on the timing chain

 

 Is the chain stretched or do you just have a bad tensioner?

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44 minutes ago, jeepwm69 said:

DID or OEM on the timing chain

 

 Is the chain stretched or do you just have a bad tensioner?

I haven't pulled it yet.  When I pull it I am replacing both.

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I took all the 3 cylinders and pistons to the machine shop this morning,  So here is the verdict.

 

1. OE cylinder and Piston is fine.  It just needs a set of rings.

2. China cylinder #1 with the Hairline crack has good Piston and Rings just the cylinder has a hairline crack in the casting.

Do you year any cam chain noise in this video?

 

3. China cylinder #2 the one with 6 hours on it. Cylinder is good and within spec.  The piston was .005 to small and the rings were .100 our of spec.  Do you think this was causing all the noise I was hearing? I put a thescope on the cam chain and tensioner while it was running and I heard nothing.

 

 

So I have 2 options.

1. Get some OE rings and use the 400 cylinder and piston.

2. Use the latest 450 Good Cylinder and the Piston from the 1st Kit and get some Shindy Rings.

 

I also just received a new Cam Chain and tensioner.  I am toying with the idea of not splitting the case and just putting in the new tensioner and the 450 cylinder and new Shindy rings.  If I pull out the old tensioner is there a way to tell if its bad?  I really don't want to tear this thing all the way down.

 

Let me know what you think?

 

 

 

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Were it me I’d put new OEM or Shindy rings on the OEM piston and use the OEM stuff

 

You should be able to check the chain stretch by seeing how close to the engine you can get the tensioner with it all the way extended (I’m thinking the 400 tensioner is similar in design to the 300, is that correct @Fishfiles?)

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1 hour ago, jeepwm69 said:

Were it me I’d put new OEM or Shindy rings on the OEM piston and use the OEM stuff

 

You should be able to check the chain stretch by seeing how close to the engine you can get the tensioner with it all the way extended (I’m thinking the 400 tensioner is similar in design to the 300, is that correct @Fishfiles?)

The sideways 400/450 engine's chain  adjuster is different than the conventional motorcycle style engines like in the 250 , 300 and 350 , here  is the section on the service manual 

fullsizeoutput_f49.jpeg

fullsizeoutput_f48.jpeg

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Thanks guys. Will I be able to tell the difference in power of the 400 head vs 450 I have been running?  I'll test out the tensioner this weekend so if I can bottom it out I am assuming the chain to too far stretched and I need to crack the case and replace the chain.  If I can't get it to bottom out then the chain should be ok?   Do you think thats chain rattle in the videos or loose piston and rings?

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24 minutes ago, jstatham said:

Thanks guys. Will I be able to tell the difference in power of the 400 head vs 450 I have been running? 

You have been running a 450 head on top a 400 piston ???  --- if so then you will likely see a dramatic increase 

 

I have a pick of the two heads side by side , the 400  dome is much smaller than the 450 ,  much more compression 

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You can see it in the pic , 400 head is on the right , 450 on the left 

IMG_6387.JPG

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I have a 1996 400 motor with a 450 Piston and Cylinder and a 400 Head.  If I go back stock it will be all 400 everything.

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I just took the tensioner off and made a video.  Tell me what you think?  I would think with the tensioner fully expanded I shouldn't be able to press it down flush.

 

 

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If your tensioner is all the way extended and housing is sitting flush, your chain is definitely is stretched  way too much and needs to be replaced

your lucky it didn’t jump time or break and 

it was most likely the source of the extra noise while running as well 

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