[Bhollins29]

Hello all. All help is appreciated.

Background. Just picked up a 2007 Honda rancher 420 from a older gentlemen that just had it rebuilt professionally (piston rings cylinder valve stem seals ect). He gave me the invoice. He took the bike on one trip and it started smoking again.

I tore the bike apart last night. I could only find that the ring gaps were closer than should be and no cross hatches in cylinder. Re honed and put back together. Still smokes. It smokes bad. Any help?

 

[b52bombardier1]

I wonder if it was sunk in muddy water before he got it??? If yes, even a professional top end rebuild will not prevent engine smoking. The cases needed (and obviously still need) to be split for a complete cleaning.

Otherwise, that fine grit river bottom mud just grinds the engine into a pasty gray metallic sludge. The only other advice I could give you is to check for blockage in the crankcase vent hose. If blocked, the blowby has to go somewhere and the rings likely can't handle it.

Rick

 

[Bhollins29]

The oil looked good when I changed it. I did a flush just Incase with marvel mystery oil before tearing it down. Oil came out great both times.

 

[JohnnySolo]

Can you video the smoking? The color will help you identify what's the deal.

 

[shadetree]

unless it was ever sunk ? ( answer above ^^ ), could be oil build up in the muffler from when it was first smoking ?.

 

[Bhollins29]

Well I just pulled it apart again. I see oil on top of the valves looking through the intake and exhaust sides. Has to be valve stem seals right?

 

[shadetree]

Well I just pulled it apart again. I see oil on top of the valves looking through the intake and exhaust sides. Has to be valve stem seals right?

no, oil flows on the top from the oil galley, oil is suppose to be there.

 

[Bhollins29]

Everything looks perfect besides that. Checked clearance of piston. It’s good. I’m lost

 

[shadetree]

Everything looks perfect besides that. Checked clearance of piston. It’s good. I’m lost

maybe i misunderstood you ?, is oil at the valve springs ?, or directly on top of the valve seats ?, if on the valve seats ?, then yes, sounds like the valve guide stem seals are bad ?, or were never replaced maybe ?. this would let oil down on the seats.

 

[Bhollins29]

I Meant on top of the valves like that. Both are oily

 

[Bhollins29]

Trying to get the best picture i can

 

[Bhollins29]

More pictures

 

[shadetree]

looks like rings are bad too me.

 

[shadetree]

I Meant on top of the valves like that. Both are oily

my money says your rings/cylinder is not right.

 

[retro]

Look at your two photos again attached to this post:

http://www.hondaatvforums.net/forum...07-honda-rancher-420-smoking.html#post1189882

Those valve seals are either missing, broken, or the valve guides are so worn out/broken that valve seals can't do any good!!!

Yank the valves out and have the guides checked by a pro. You'll need to replace the valve seals at a minimum.

Do Not take it back to the same shop the "repair" (LOL) invoice come from. You said the cylinder had no cross-hatching either, which to me indicates someone has been lying about that motor!!!

I doubt its ever been rebuilt according to your explanations. Get a copy of the service manual from the site HERE and have fun with it!

 

[fishfiles]

that is a lot of oil , the valve stem seals may have not been changed , or have been damaged during installation , the stem of the valve may be worn down , the valve guides might be worn out , that really don't look like one trip on a fresh rebuild , that included doing the head

when you do get it running again , take in mind as Shade mentioned above , it can take a while to burn all the oil out the exhaust from the previous problem ----I had one that smoked for 2 hours after a rebuild and was I about to pull it down again and either the oil burned out the exhaust or the rings finally seated as it quit smoking , but looking at your valve , I think you got a problem there

 

[Bhollins29]

Thanks all for help. Keep it coming. Valve stem seals are going in tomorrow.

 

[shadetree]

Thanks all for help. Keep it coming. Valve stem seals are going in tomorrow.

odd's are, if they did not replace the seals ?, then chances are, the top end was not rebuilt either ?..or !, the rings are worn from it being sunk ?. keep us updated plz !.

 

[Bhollins29]

Well gentlemen. I rebuilt the ENTIRE top end. She runs great now!

 

[rustneversleeps]

I wonder if it was sunk in muddy water before he got it??? If yes, even a professional top end rebuild will not prevent engine smoking. The cases needed (and obviously still need) to be split for a complete cleaning.

Otherwise, that fine grit river bottom mud just grinds the engine into a pasty gray metallic sludge. The only other advice I could give you is to check for blockage in the crankcase vent hose. If blocked, the blowby has to go somewhere and the rings likely can't handle it.

Rick

can you tell me were this Crankcase Vent Hose is on the 2013 420 i couldn't fine in the service manual..(Is it the one on top of that gas tank.)
The reason why i ask is i have to add oil every 2k or 3K Km and only very little or if any blue comes out of the Exhaust.
But while I'm driving I smell fumes from the exhaust or is it coming from were i sit on the seat cause I'm going fast enough you think it would just blow away....hope it make sense..