rancher engine rebuild

16597 Views 56 Replies 8 Participants Last post by dennisdamence1414, 2 mo ago

swamperdonker

Discussion Starter · Aug 12, 2014

So I'm rebuilding my rancher 420 motor and I have a couple questions. 1. How do I get the valve spring seats out? Mine are broke off. 2. How do I get the flywheel off? I've heard you have to have a flywheel puller or you can use a bolt??? But I was thinking I can just leave the flywheel on and just leave the crankshaft in that half of the case. can someone fill me in on that? 3. What's the easiest way to split the cases without damaging anything once you've got the clutches and everything off? And lastly, shouldn't I go ahead and have it bored while I've got everything taken apart? I've never heard it run so I don't know if it smokes. Oh and one last thing, does anyone have any suggestions as to what I can do about a stripped oil drain? The previous owner stripped the plug out and it wont get very tight so I figured why not go ahead and knock that out so it doesn't come back to haunt me.

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brantley11

· #2 · Aug 13, 2014

If you are talking about part #2 below then they have to be pressed out. I get all of my machine shop work done at Massey Automotive off HWY 80 in Jackson. They will do a head job for $25.

The flywheel uses a 18mx1.5 bolt--you can also buy one at Got Gear or Mug Predators.

Are far a splitting the cases I use a dead blow hammer and a large punch and hit on the two taps on the sides of my engine. You can also use a 2x4 and lever the cases apart.

I would only bore it out if you were smoking.

On the stripped drain plug you could JB weld a large nut on the bottom around the original hole and have a new plug--that is what I did to my brother in laws 300 when his oil plug stripped.

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jeepwm69

· #3 · Aug 13, 2014

Yep. While you're in there, replace
Front and rear output seals
shifter seal
reverse shaft seal (where the reverse cable hooks up)
Check your clutch drum for grooves and pads for wear
Replace the timing chain and adjuster

Get a flywheel puller. They're cheap and worthwhile. I got mine off ebay for about $15 IIRC. Basically a big bolt, but good luck finding the right size/thread pitch at the local hardware store.

I'd plan on replacing the crank if you break it all the way down. IIRC you're working on an 08. The 2012 crank is exactly the same as the 2008 crank, but the 2012 crank is $100 cheaper.

I'd have the jug checked for out-of- round and hone it with new rings at the least. If it were me, I'd take it to a machine shop, have them measure, and then bore and hone it.

I've learned over the years that doing it right the first time is much cheaper and easier than trying to cheap out on it and half azz it, because then you end up spending more money going back in to address things you thought were ok.

You do the crank, timing chain, clutches, top end, you should be good to go for a long time.

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swamperdonker

Discussion Starter · #4 · Aug 14, 2014

Jeep, do I really have to replace the crankshaft? I know its not worth my time if I'm not going to do it right but that's still a $400 part and I really don't have a lot of money to play around with here. How can I tell for sure I need a crankshaft? As for the seals that definitely seems worth it. Do those come with gasket kit B?

toomanytoys

· #5 · Aug 14, 2014

If you don't rebuild it correctly you are throwing the money away.

You can check the crank with a micrometer using Honda's specs.

JWJR

· #6 · Aug 14, 2014

Order gasket set a and b. Check the crank real wheel using specs in service manual because you will kick your self in the ass if you get it together and it still knocks because the crank was bad.

jeepwm69

· #7 · Aug 15, 2014

If there is ANY up and down play in the crank you need to replace it. A little front to back is normal, but up and down means new crank. I think it was like $275 from Honda East Toledo, but that's for the 2012 crank.

Gasket sets A and B don't include the front and rear output seals, shifter seal, and reverse seal, but those seals are cheap and easy to do while the motor is pulled, and a pain to do with the motor in.

JWJR

· #8 · Aug 17, 2014

Get you a couple of the front output seals...they are a pain to get in with out tearing them.

JWJR

· #9 · Aug 17, 2014

I was thinking I read somewhere the 2012 up crank had something different that didn't allow it to work in the older models. Could be wrong though.

swamperdonker

Discussion Starter · #10 · Aug 17, 2014

Ok so I've been thinking. How can I make sure that the timing is correct because I can see where one of the valves nicked the piston and bent the valve stem. But that could be improper clearance but I want to be sure. I put a mark on the cam to line up with the marking on the case but I just wanna be absolutely sure

brantley11

· #11 · Aug 17, 2014

There should be a mark on the cam shaft end and a punch on the cam chain sprocket. Lines those up with the point / mark on the crankcase while it is in TDC and you will be fine.

rich450es

· #12 · Aug 17, 2014

everything you need to know on how to rebuild the rancher engine is in the manual ,,,,get one and read it

swamperdonker

Discussion Starter · #13 · Aug 17, 2014

brantley11 said:
There should be a mark on the cam shaft end and a punch on the cam chain sprocket. Lines those up with the point / mark on the crankcase while it is in TDC and you will be fine.

Is this what you were talking about? Because when I got in the motor it was exactly opposite

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jeepwm69

· #14 · Aug 18, 2014

I'd guess the prior owner tried to fix something and didn't get it back together right. If you get a manual it will tell you everything you need to know. If you look around on here there's a link to the manual because I downloaded it here and used it when I rebuilt my 07 Rancher

brantley11

· #15 · Aug 18, 2014

here is a good series of youtube videos that show breaking down a Rancher engine and putting it back together.

https://www.youtube.com/watch?v=eUSG5ChP0TE

jeepwm69

· #16 · Aug 18, 2014

Yep, I used those and the manual when I did mine. Was pretty easy rebuild

swamperdonker

Discussion Starter · #17 · Aug 28, 2014

Ok so when I'm selecting my machine for a parts schematic which one do I pick trx420 fm 2a? Trx 420 fe??? After the trx420 I'm lost. Oh and my machine is a 2008 honda rancher 420 foot shift 4x4

toodeep

· #18 · Aug 28, 2014

TRX420FM (4x4/manual shift)

swamperdonker

Discussion Starter · #19 · Aug 28, 2014

There's a "420FM A" and "420FM 2A"

toodeep

· #20 · Aug 28, 2014

A... 2A is the camo.. As far as motor parts either one will work. My parts fiche I don't choose the area section so it shows both when I'm looking up parts.

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