2013 Honda 420 smoking

[KRi1iKaL 0]

I have a Honda 420 that I bought used and within 30 minutes of having it home, the engine was leaking oil. I had the whole engine rebuilt bottom and top end. It ran good for 2 months but started to smoke like crazy at start up and as it ran. I pulled the top end off to take a look. Nothing stands clearly out to me but my only knowledge is from the forums.

 

One thing I noticed is that the bottom rings snd oil rings are significantly smaller than the top two ring on the piston. Is this normal?

 

Also, let me know what you think of how much the gasket restricts coolant flow.

 

Would love any inputs.

 

Thanks guys,

[jeepwm69 7,636]

Welcome aboard!

 

It's been awhile since I was in a 420, but yes, the top two rings have much more spring to them, and stick out farther than the oil rings.

 

You say you had the bottom end rebuilt.  What all was done?  New or rebuilt crank?  Is there any play at all between the wrist pin and small end of the rod? (stick one end of the wrist pin in until the end is flush with the other side, and wiggle  up and down)

 

Was the bottom end thoroughly cleaned out before reassembly?

 

What top end was used?  New aftermarket, bore job on factory cylinder, or ???

 

The heads changed on the 09-up 420's, and I'm wondering if that gasket might be for the 09-up head while you have an 07-08 head.

 

 

[KRi1iKaL 0]

34 minutes ago, jeepwm69 said:

Welcome aboard!

 

It's been awhile since I was in a 420, but yes, the top two rings have much more spring to them, and stick out farther than the oil rings.

 

You say you had the bottom end rebuilt.  What all was done?  New or rebuilt crank?  Is there any play at all between the wrist pin and small end of the rod? (stick one end of the wrist pin in until the end is flush with the other side, and wiggle  up and down)

 

Was the bottom end thoroughly cleaned out before reassembly?

 

What top end was used?  New aftermarket, bore job on factory cylinder, or ???

 

The heads changed on the 09-up 420's, and I'm wondering if that gasket might be for the 09-up head while you have an 07-08 head.

 

 

Thanks for the response man.

 

Bottom end was completely split open and cleaned out with new rod, one way bearing, timing chain, and clutches. I consider the guy that rebuilt it to be trustworthy and he sent me pictures. 

 

He mentioned having the topend bored by a local machinist but I'm not sure where he got the cylinder from. 

 

I will check wrist pin when I get home but everything to my knowledge should be new and looks different from when I pulled the topend off the first time it smoked. 

 

Just strange that it ran so well for 2 months and then started to continously smoke. I've got 1700 dollars in it on top of the 3200 I paid so I want to be sure I get it right. 

 

The only thing I can think is possibly my valve guide is bad if it isn't the piston rings. 

[jeepwm69 7,636]

2 hours ago, KRi1iKaL said:

Thanks for the response man.

 

Bottom end was completely split open and cleaned out with new rod, one way bearing, timing chain, and clutches. I consider the guy that rebuilt it to be trustworthy and he sent me pictures. 

 

He mentioned having the topend bored by a local machinist but I'm not sure where he got the cylinder from. 

 

I will check wrist pin when I get home but everything to my knowledge should be new and looks different from when I pulled the topend off the first time it smoked. 

 

Just strange that it ran so well for 2 months and then started to continously smoke. I've got 1700 dollars in it on top of the 3200 I paid so I want to be sure I get it right. 

 

The only thing I can think is possibly my valve guide is bad if it isn't the piston rings. 

 

I've had a 420 with a good bore that started smoking again.  I honed the cylinder again, put another set of rings in it, and it ran fine after that.

 

If you paid someone for the work he should look into it and make it right.  If he used an aftermarket chinese cyilnder/piston/rings then you might have gotten a junk part. 

 

Or if he had the cylinder bored oversized to a new piston and rings, find out who did the bore job, and what brand piston/rings were used.  Sometimes you get a bad bore job (for example, Toodeep's shop had that problem (bad bore jobs they had done at a local machine shop), and subsequently started using new OEM cylinders and pistons on rebuilds, rather than risk getting a bad bore job that he would have to eat)

[Fishfiles 20,145]

There is so much to think of here , and so much you can answer as you never did the work >>>>> was the bore job done right ?  --- was the correct size piston and rings used ? --- was quaility parts used ? ( or china junk ) --- was the wrist pin journal in good condition ?  ( if that piston was wobbling , it would not last long ) --- was the engine properly broken it ? --- were  the valve  guide seals replaced ? --- were the valve guide seals maybe damaged during installation ? ---- did the engine run hot ?  maybe from a clogged up radiator ? ---- 

[KRi1iKaL 0]

24 minutes ago, Fishfiles said:

There is so much to think of here , and so much you can answer as you never did the work >>>>> was the bore job done right ?  --- was the correct size piston and rings used ? --- was quaility parts used ? ( or china junk ) --- was the wrist pin journal in good condition ?  ( if that piston was wobbling , it would not last long ) --- was the engine properly broken it ? --- were  the valve  guide seals replaced ? --- were the valve guide seals maybe damaged during installation ? ---- did the engine run hot ?  maybe from a clogged up radiator ? ---- 

This is my first time doing anything engine related and my only source of knowledge has been these forums. It is very possible I did not break it in right.  I didn't do much other than ride it without letting it idle while throttling the rpms and then letting it cool down while off.  Changed oil and then rode it normally. 

 

Valve seals were said to be changed and valves lapped. I took my exhaust valve out and there was nothing obvious. Maybe I should test with gas and air?

 

Wrist pin is new I believe but I'm hesitant to take my piston off.

 

I did feel like my engine was getting hotter than normal but it's the middle of summer and no warning light and fan kicked on religiously. It is snorkeled with radiator relocated which my ! didn't realize that was a red flag it got sunk. The guy I bought it from used water in coolant which caused alot of oxidation. After rebuild only coolant was used. All hoses had coolant when disconnected.

 

The guy that fixed it is a good guy and does a good job and the fourwheeler Is a complete piece of crap. I think he's aggravated I took it apart instead of bringing back to him. 

 

I will post more pics when I'm home from work around 6:30.

[Fishfiles 20,145]

It is not the wrist pin which causes the problem , as the wrist pin  is usually always change , it is the journal of the connecting rod ,  where the wrist pin rides that gets worn and causes the wobble , that requires crank work to fix , by pressing a new 

 

you can take the top ring off the piston and stick it back into the bore , square it up and hold the jug up to a light and see if you see a gap between the ring and cylinder wall , move the ring down the bore to several spots and test again

 

 also maybe the rings where installed improperly , the wrong ring in the wrong groove or maybe upside down  

[KRi1iKaL 0]

5 hours ago, jeepwm69 said:

 

I've had a 420 with a good bore that started smoking again.  I honed the cylinder again, put another set of rings in it, and it ran fine after that.

 

If you paid someone for the work he should look into it and make it right.  If he used an aftermarket chinese cyilnder/piston/rings then you might have gotten a junk part. 

 

Or if he had the cylinder bored oversized to a new piston and rings, find out who did the bore job, and what brand piston/rings were used.  Sometimes you get a bad bore job (for example, Toodeep's shop had that problem (bad bore jobs they had done at a local machine shop), and subsequently started using new OEM cylinders and pistons on rebuilds, rather than risk getting a bad bore job that he would have to eat)

Check these pictures out. To me it looks like my cylinder is only partially honed? My piston feels solid to the crank. I'm thinking I get it honed, measured, new rings, and see where I'm at. Can I reuse my gaskets? Can I drill gaskets to increase coolant flow?

[KRi1iKaL 0]

3 hours ago, Fishfiles said:

It is not the wrist pin which causes the problem , as the wrist pin  is usually always change , it is the journal of the connecting rod ,  where the wrist pin rides that gets worn and causes the wobble , that requires crank work to fix , by pressing a new 

 

you can take the top ring off the piston and stick it back into the bore , square it up and hold the jug up to a light and see if you see a gap between the ring and cylinder wall , move the ring down the bore to several spots and test again

 

 also maybe the rings where installed improperly , the wrong ring in the wrong groove or maybe upside down  

Check these pictures out. To me it looks like my cylinder is only partially honed? My piston feels solid to the crank. I'm thinking I get it honed, measured, new rings, and see where I'm at. Can I reuse my gaskets? Can I drill gaskets to increase coolant flow where it was blocked?

 

[jeepwm69 7,636]

It's really hard to tell if you have a good bore without machinist tools to measure.  Can you catch any of those scratches with a fingernail, or are the really shallow?  The area with the crosshatch is what your cylinder should look like.  The rings will wear the crosshatch off where the piston rides, but the area the piston doesn't travel will retain the crosshatch.

 

You'll need new gaskets, and make sure you get them for the proper cylinder and head.  There was a change between 2007-2008, and 2009 and up.  It's possible you've had your head/cylinder swapped so just getting one for what you think you have might not work.  I'd ask your mechanic what he used, and order the other one, see if it has better clearance on the cooling holes.

 

You DID use 50/50 antifreeze and water, and not just straight antifreeze concentrate, right?  Straight water is bad, but so is straight coolant.

 

Any sludge the the bottom of the crankcases, or did the guy do a good job of cleaning everything out?  If a machine was snorkeled, good chance it was sunk.  If you don't really, really, really clean out the crankcases thoroughly, you can have grit in the bottom end that came in with the water, and that grit will work it's way up and ruin a new top end. 

 

This was a snorkeled Rubicon I just rebuilt.  You can see the sludge in the bottom of the engine here, and then scroll down and see what it looked like before I put it back together.  It needs to be clean enough to eat out of.  I use cans of starter fluid and hose them out till spotless, then squirt clean new oil back in the bearings as the starter fluid will leave them dry.

 

 

[jeepwm69 7,636]

Same thing here on this 500 FM engine(s)

 

 

Gotta be spotless.  If he didn't get your cases cleaned out you might have had residual grit in there that roasted your new top end.

 

If he DID clean everything out well, then you could have had rings that weren't right (check endgap), a piston that's off (I've had a couple over the years that weren't right, but the machinist caught it before the bore).

 

He DID bore the cylinder and use a new oversized piston, right?  Or did he just hone it and put in new rings?