[XJCountry]

First thread started (second post).

Backstory:
Bought a 2000 Foreman 450ES that had been sitting for several years. Old man said that it was running when parked. Went to pull the starter cord and it wouldn't budge (in neutral). Put it in gear and tried to pull it with my vehicle and the tires didn't turn. In neutral it rolls. He wanted $500 for it, but talked him down to $800 if he would throw in a rancher 350 he had that was running decent (has its own issues). Got them both on the trailer and headed 2 hrs home.

Wrenching:
Wanted to see if the engine would turn so pulled the starter cord again...no dice. Poured some mystery oil (MMO) in the cylinder and let it sit overnight. Still wouldn't pull so decided to see if I could push the piston down with compressed air and it went down until the intake valve actuated and started blowing back through the carb. This is positive progress...right?

Then tried to pull the front diff, but when I got to the rear lower bolt it backed out 1/32" and then stopped and would not budge. Put impact with 120 psi to it and it didn't move. Put a breaker bar with a 4' cheater on it and broke a socket and a socket extension and then rounded the bolt (dang 12 pt sockets). Switched to the rear axle to make some progress and got the rear axle out from under it. What a godawful mess! water invaded driveshaft tube and looks like it was driven hard afterwards. Oh yeah, the swingarm is sitting in there slightly cockeyed so it will need new bearings, seals, etc. and the rear output driveshaft boot has collected a metal crescent (one of the driveshaft housing bearings I think). Have to build a locknut removal socket before I can diagnose this issue more.


This is where it sits currently. Been working other projects, but saw some really good posts on here and decided to see if anyone had ideas on the motor not turning. I really don't want it to be a broken crank, but if it is I found a youtube video that shows a guy rebuilding his atv motor...what can go wrong? I have a digital copy of the repair manual for this model so a complete rebuild may be in order.

What do you guys think? Is there anything else I can do except pull the motor and start tearing into it?

Thank you for your help,

XJ

 

[fishfiles]

my first guess would be a timing chain with excessive slack causing a valve to hit the piston , a cam down the spark plug hole might show something

 

[XJCountry]

Thanks, Fish! I had the valve cover off when I put air to the piston and could see the intake valve actuate when the piston went down so maybe it isn't the crank... When I pulled the starter cord I wasn't looking at the valves, so that would be a good one to check out. Would be a good idea to check timing marks as well. If these jump time does it damage anything? Would I be good to get it back on time and replace the chain tensioner?

 

[fishfiles]

I don't know if a 450's valve will hit the piston with a out of time situation , I have a 450 but that never happened yet , I have done it on a 300 and it turned out nasty in the pic below

when you said it stops right before TDC , that makes me think the piston may be hitting the valve

I had to put a new crank in my 2002 450 because the journal was wallowed out at the connecting rod , it was right at $250 from Honda

 

[XJCountry]

Ouch! Hard to make compression with that setup.

 

[XJCountry]

Also drained the oil and ran a magnet around the plastic bottle I put the oil in. No metal fragments. Ran a magnet down in the crankcase, through the oil fill hole and didn't pick any thing up there either. Didn't see any non-ferrous bits in the oil and no emulsion or water. I will check timing in the near future and see what I can find.

 

[fishfiles]

How is it going

something else you could have done was pour that drained oil from the plastic bottle thru a coffee filter so see what non-metallic particle were in there

 

[XJCountry]

Tried to scope it, but the scope my dad has is a harbor freight. I.e. can't make out anything on the tiny screen and the scope won't go through the spark plug hole.
I did get a swingarm lock nut socket made. Kinda ugly but it actually fits in there really well. Pics of the hack job below.

Next have to make a 17mm hex for the other bolts. Spent 45 min in the pawnshop sorting through their junk sockets to try and find a sparkplug socket with the right hex size on the back end. Closest I could find is a Matco long socket, but it is a loose fit in there. Seems like a 15mm or 16mm. The others are all 19mm. Probably grind one of them down to 17mm.

I have resigned myself to the fact that I need to pull the motor. At the least. Next have to cut the bolt on the front diff. Not looking forward to that.

 

[XJCountry]

Also, paid a little more attention when I had the spark plug off last and I don't think it is getting anywhere close to TDC. Looks like it is coming about 1/2 to 2/3 up in the stroke before it stops. So I couldn't check timing... This is why I am pulling the motor.

Does anyone know where to get swing arm, axle, and engine rebuild kits for a decent price? Definitely need the full swing arm and axle rebuild kits. Engine will need something, but don't know how much it needs just yet.

I figure I have $200 in this one and would love to get it back on the trails for $1000 or less. As long as I can get the parts for reasonable and there isnt anything bad wrong I think i can get hopefully spend another $500 and have it ready. If I sell the Rancher I got with it I might have $0 or less in it.

 

[XJCountry]

UPDATE: Got the motor out yesterday and when I turn the crank by hand (Ratchet hand that is) it seems to be getting hung up at the bottom of the stroke now. I think I either have a broken crank or something is floating around in the crankcase and it just shifted to the bottom after turning the engine on its side to get it out of the frame. it was getting hung up somewhere in the top 1/3 of the stroke before...

What do you guys think? I am seriously considering taking it in to a honda tech for a rebuild now that I have it out. But then again I have a goal of getting this on the trails for little cash input. I guess I will call Honda and they may make my mind up for me...

 

[XJCountry]

UPDATE: Let the motor sit on the bench for a few days (was out buying more ATVs). Got on it late one evening and was cleaning it up externally and tilting and rolling it all different directions. Well, I decided to roll the crank again and tilt it in different directions. Thinking that there was something floating in the crank case. After rolling it pretty hard into the 'stop spot' and then tilting it at a different angle it would turn free! it was late and I planned on dropping it off at the local shop for diagnosis so I loaded it and went to bed. It rode in the back of my Jeep for the next day and shifted some. When i got to the local ATV mechanic and put it on his bench the crank turned full revolutions with no stop. I left it there, but they have a 2 month lead time before they get on a project. This was about 2 weeks ago.

My question for you guys is do I go pick it up before they tear into it. Could there have been a rust ring that was stopping it from turning full revolution?

This one was sitting outside for several years before I got it and the factory snorkel had rotted on the top and I am sure had let some water get into the cylinder at some point...

It will cost about $100 for them to look into it, but If it ain't broke I don't want to mess with factory seals and gaskets.

WWYGD? (What Would You Guys Do?)

Thanks for all the help.

 

[shadetree]

I know what I would do ?..i'd fix it myself..lol. odds are ?, a bent or broken valve ?, busted piston skirt ?, broken oil pump ? ( they turn off the crank ). only way to find out ?..IS TEAR INTO IT !..LOL.

 

[shadetree]

heck, load it up, haul it down to me, i'll show ya how to work on that rancher motor..lol.

 

[fishfiles]

WWID ( what would I do ) = I would do it myself , I would take the head off first , see if the piston is coming to the top of the deck , then I would pull the jug off and see what the piston , bore , connecting rod looks like -----my guess of what was stopping it from turning is a broken piece of piston jamming up , I would theorize that the piston broke cause water got into the cylinder at one point , bent the rod , running it with a bent rod broke the piston , I say that cause it happened to me before

 

[XJCountry]

Thanks for the input! I think I will pick it up from the shop and pull the simple stuff (head and Jug) like Fish says to see what is going on with it. If i get in over my head I may load everything up and take shadetree up on his offer!

Have a good one.

 

[fishfiles]

XJ', what model do you have ?

 

[XJCountry]

It is a 2000 Foreman 450 ES.

 

[fishfiles]

That makes it easier , the cam in the crankcase and is a push rod engine and not an over head so there is no timing of the cam or cam chain to deal with , it is really easy , I have my 2000 TRX450FM apart right now , I am sure you can get some help here and a copy of a manual if you don't already have one and save your self a bunch of money from not letting someone do it for you

 

[shadetree]

That makes it easier , the cam in the crankcase and is a push rod engine and not an over head so there is no timing of the cam or cam chain to deal with , it is really easy , I have my 2000 TRX450FM apart right now , I am sure you can get some help here and a copy of a manual if you don't already have one and save your self a bunch of money from not letting someone do it for you

ehhhh..I wan't gonna charge him anything, seeing how he would be here watching and helping..lol.

 

[shadetree]

which one is broken ?, you said rancher , now its the foreman, not that it matters !, I know both inside and out..lol.