Topic: 400F motor teardown

[fmctm1sw]

Well, the idea started out innocently enough.  I had a locked up 400F motor and a bunch of 350F motor parts so the game plan was to remove the top end from the 400F and put a 350F top end on it.  There was no hope for the top end of the 400F.  Someone took whacks at it with something and broke a bunch of fins on the jug and head.  The first 4 photos shows the engine as I got it.

[fmctm1sw]

I think I'll be able to salvage the valve cover.  The bolt photo'd stripped though but not a big deal since I can't use the head anyway.  The next set pf photos shows me getting the valve cover off.  I half expected to see the camshaft all tore up and the rockers ruined.  I was pleasantly surprised by the rocker arms and the camshaft had crud forming where it was stuck against the rockers.  I'm going to clean it up with a brass brush and see what happens. 

[fmctm1sw]

Right about here I lost about 10 pictures bacause my disk failed in my camera.  What I wanted to show was the position of the cam sprocket.  I almost was able to get both bolts off it.  One was too low to reach and then I realized the cam chain tensioner bolt was broken off    Oh well, I know I was in this for the long haul now.  I lost any hesitation about cutting the cam chain off.  The first thing I tried was grinding one of the rivets out but this thing would not budge.  I ended up cutting a link in half. 

[fmctm1sw]

Next is a couple photos of the progress.  I got the clutch cover off and the camshaft out.  I'm getting ready to free the top end.  Of note, I lost more pictures with my disk at his point.  I just dont' learn.  I decided it would be prudent to make sure the oil was drained before I took the clutch cover off.  That proved unnecessary.  Oil?  no.  Dirty brown watery substance?  yes.

[fmctm1sw]

After seeing that "oil" drain out, I knew I had water in this.  The next photos show the top end coming apart.  I had a hell of a time getting it off.  I used a small peice of 2x4 to hammer up on each side.  In the end... free at last.

[fmctm1sw]

I got all the pistons out.  Dirty but I wonder if they will clean up enough to be salvagable?  Adding insult to injury, the connecting rod #4 was stuck.  I was able to get it to move but it is very sticky.  I figure I have either a siezed bearing or water in it binded it somehow.  No matter really, the whole thing has to come apart anyway.  The last photo tries to illustrate the stuck rod.  I wanted to capture the others limply laying against the case while this one stood... well... erectly 

[fmctm1sw]

I didn't get  alot of photos of the actual splitting of the cases.  I ended up leaving the flywheel on since I don't have a M18-1.5 bolt to get it out and the spark advancer was really stuck as well.  The only too I really needed and didn't have was a pair of retaining ring pliers large enough to remove the shaft the primary chain is connected to.    I was able to get enough slack in it to get the top cover off.  The other thing I found with was the cam chain tensioner.  I neglected to remove it and that prevented the top case from coming off.  So now the top case is off and the bottom is still on since I can't get that retaining ring out right now.  I did manage to snap 3 or 4 bolts off though.

[fmctm1sw]

So that's kind of where it is right now.  I think the cases are ok but I busted off bolts in it as mentioned.  And I'm beginning to think someone has already been in here.  There was some kind of sealant between the cases and the tensioner mechanism had stripped threads (or I did it taking it out).  Now I'm wondering if I just try to clean up and salvage the pieces on ebay or I try to get it back together.  And what of the crankshaft and stuck connecting rod?  The last photo shows the oil pan with all the crap in it.  It honestly was not as difficult (on the mechanical side of things) as I thought it would be.  Physically was another story, the bolts in the case were extremely difficult to get out.  The ones that came out in one piece sure sounded like they wanted to snap too.  Scrap or opportunity to really get the cases cleaned up and painted nice?  I don't know...   

[fmctm1sw]

I'm just now thinking about getting back on this.  Thanks to this thread:  http://forums.sohc4.net/index.php?topic=64882.0

Shouldn't have sold the tensioner assembly...

[fmctm1sw]

Got a lot more photos to post later.  Noticed the shaft that my shift forks are on is bent.  #4 in the photo.

[fmctm1sw]

More pictures.  First shows all the worms I pulled out.  I noticed the bolts that snapped had a lot of that stuff on them.  Someone was definitely in here before.  Maybe this stuff laying around all thorough the engine contributed to the seized connecting rod somehow.

Next is the shift drum and forks (rusty).  That shaft is bent.  Right about where the fork is shown in the next photo.  I'm sure glad I noticed that before I put this all back together.  Definitely a poorly cared for engine.

Next on this list:  Aluminum safe paint stripper.  Maybe the aircraft stripper is, and I have some in my garage.  We'll see.  I've also been eyeing that soda blaster contraption shown in another thread...

[fastbroshi]

We don't see many motor teardowns on here other than 750s and 550s, with a 450, 350 or 360 here and there.  Nice to have some variety.  Make sure and take plenty of pics of the valvetrain and tranny.

[fmctm1sw]

Well, this sat on my shelf for the better part of a year.  I blasted it and painted it along with the 550 motor I did.  The original plan was to put a 350F top end on this bottom end.  Maybe, maybe not but I wanted to document it...

[RickB]

You've no doubt seen the 400F motor rebuild threads by Jensen?

http://forums.sohc4.net/index.php?topic=65233.0

and

http://forums.sohc4.net/index.php?topic=65353.0

A very switched one guy.

Rick.

[fastbroshi]

I have Rick, the threads you cited were started about a week after I made my comments.