[dmvu]

Hello, I have a 2011 rancher 420 with auto and power steering. It has a tapping sound from top end which sounds like valves need adjusting. And it smokes white but I can smell oil. Not much or any smoke when idle but when rev high, smoke comes out. I pulled the spark plug out and it was black and oil was on it. I'm debating about doing a top end rebuild instead of bringing to shop and see if that will fix the smoking. I can adjust valves as well. I looked online at top end kits, I would just need to change the piston, rings, clips and gaskets? And have read to change valve seals since I'm there already? Would that fix the issue? The bike has 255 hours and a little less than 1500 miles. Still has power and runs good. The tapping sounds goes away after it's warmed up. Would I need a new cylinder as well? Is a new piston even required? I'm guessing it could just be the rings or hopefully just rings. If anyone has a guide, preferably with photos or a video somewhere I would greatly appreciate it as well. I've never done any work on an atv but have worked on cars. Thank you

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[JohnnySolo]

Just what I would do, but the pros here may have different take one it. I would reset valves to where they need to be and see where that puts you, a lot of the symptoms seem like they could be fixed by a valve adjustment but then again it may do nothin. It won't hurt to do it anyway so I would. Get you a feeler gauge, and it may be a 11/16" socket to get valve caps off and will need a 10mm wrench.

 

[dmvu]

Just what I would do, but the pros here may have different take one it. I would reset valves to where they need to be and see where that puts you, a lot of the symptoms seem like they could be fixed by a valve adjustment but then again it may do nothin. It won't hurt to do it anyway so I would. Get you a feeler gauge, and it may be a 11/16" socket to get valve caps off and will need a 10mm wrench.

Ok thanks. Does a valve adjustment also affect oil burning?

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[dmvu]

If anyone can give advice. I'm looking at the namura top end kit. 86.48mm which I think is stock bore size. Na-10042K. Looks like it has everything I need to do top end.

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[alloutdoors]

I would set the valves and see how the ATV behaves afterwards vs just tearing into the top end. As for smoke, well you certainly can have bad oil rings and/or getting coolant in the top end as well. Read through this old thread and think about next steps http://www.hondaatvforums.net/forum...x420fe-blowing-white-smoke.html#/topics/47374

 

[retro]

That is some very low hours and miles on your Rancher. I'm gonna guess... has it ever been sunk? If so you'll have to split the cases for a thorough cleaning to save it.

 

[JohnnySolo]

Just what I would do, but the pros here may have different take one it. I would reset valves to where they need to be and see where that puts you, a lot of the symptoms seem like they could be fixed by a valve adjustment but then again it may do nothin. It won't hurt to do it anyway so I would. Get you a feeler gauge, and it may be a 11/16" socket to get valve caps off and will need a 10mm wrench.

Ok thanks. Does a valve adjustment also affect oil burning?

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Don't think so, only thing I'm thinking is it can leak if there isn't a tight seal on valve head. Like I said good bit of those symptoms can be fixed by resetting the valves.

 

[Jeepwm69]

Where are you located dmvu?

I've never seen one smoke from valves not being set right. If it stops smoking when it warms up you might have bad valve stem seals, otherwise you probably need rings at a minimum.

You can pull the top end, hone the cylinder, and slap new rings on it and see if that works.
Will cost you a gasket set and the cost of rings, but might not fix it.

You can send the cylinder to G&H or a local machine shop, have them bore it to match a new oversized piston. This should fix it, unless it's been sunk and there is grit in the bottom end. Will cost you a couple hundred bucks, and again, if it's been sunk and has grit in the bottom end, it won't last.

You can pull the motor, disassemble it, clean out the bottom end, reassemble, and do the bored cylinder/ new piston route and it will be fixed.

The third option requires a lot of work, but not really any more expense.

Also, if you're feeling frisky, you could buy a new Foreman 500 (2012-up) cylinder and piston and bolt it on. Direct fit, and adds about 55CC's. Not a tremendous uptick in power, but if you're doing it anyway, now's the time to upgrade.

 

[dmvu]

Where are you located dmvu?

I've never seen one smoke from valves not being set right. If it stops smoking when it warms up you might have bad valve stem seals, otherwise you probably need rings at a minimum.

You can pull the top end, hone the cylinder, and slap new rings on it and see if that works.
Will cost you a gasket set and the cost of rings, but might not fix it.

You can send the cylinder to G&H or a local machine shop, have them bore it to match a new oversized piston. This should fix it, unless it's been sunk and there is grit in the bottom end. Will cost you a couple hundred bucks, and again, if it's been sunk and has grit in the bottom end, it won't last.

You can pull the motor, disassemble it, clean out the bottom end, reassemble, and do the bored cylinder/ new piston route and it will be fixed.

The third option requires a lot of work, but not really any more expense.

Also, if you're feeling frisky, you could buy a new Foreman 500 (2012-up) cylinder and piston and bolt it on. Direct fit, and adds about 55CC's. Not a tremendous uptick in power, but if you're doing it anyway, now's the time to upgrade.

Louisiana. Yeah I was figuring smoking has nothing to do with the valves. The valve tapping sound stops when it's warmed up. The smoking is only when high rev. At idle it doesn't smoke. I was looking at giving a shot at the namura top end rebuild kit. It has new piston, rings, valve seals, gaskets. For 110 shipped. I would just need a tool to hone the bore. Do you know what stock bore size is? If only 250 hours I'm pretty sure the walls of cylinder shouldn't be all worn out though. Not sure until taking it apart. I really don't want to take apart bottom end though. Not sure if it's ever been sunk. I just know it smokes white and burns oil and has taping sound from top end.

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[Carolynskii]

^^^ what Jeep said.
Obviously you know it needs taken apart so do that and see what you see that needs attention.
You'd be able to see what type of wear you have and if it's bad or not. However it should be taken to a shop to mic it and see if its egg shaped. If you think piston and cylinder look ok then reassemble but plan for new valve stem guides and do an adjustment for good measure then see where you're at.
Before you start check the oil and see if it's milky at all.

 

[misterclean59]

I don't think an engine that smokes white smoke would be repaired properly if just the piston and rings replaced. Usually if it smokes then the bore is out of spec or almost out of spec which requires a bore. If you think about it, if you are already buying a piston......might as well bore it to the next oversized piston and make it like new. Of course do a valve job and seals.

 

[Carolynskii]

... and if you're in the Baton Rouge area then Rad cycles by LSU does hone and boring of cylinders for like $50. So does extreme speed in plaquemine and they don't send it out they do it on site which is who I use.
You don't want to order a piston kit till it's been mic'd if you observe excessive wear when you take it apart because you don't know what size it will need to be bored to correct your problem. Extreme speed doesn't charge a ton for my piston kits either so I usually order those thru him because he determines what size I need.
But I do get stock gaskets from Honda because they are a lot cheaper than aftermarket.

 

[Jeepwm69]

Tapping is likely valves. When the metal warms up it expands slightly, taking up the slack that is causing the tapping.

Carolynskii and MC are correct, you don't want to order a new piston unless you're planning on boring the cylinder, and if you go that route the machine shop has to measure the cylinder BEFORE you order the piston so they know which size over to tell you to order. They will then use the piston to precisely bore the cylinder to match it.