Honda ATV Forum banner

41 - 60 of 77 Posts

·
Registered
Joined
·
48 Posts
Discussion Starter #41
All rings are out of spec. So rings, valve seals anything else to check?


Sent from my iPhone using Tapatalk
That piston looks scuffed. If so replace it too. A quick method to check piston to cylinder clearance is to measure with a feeler gauge. It's not perfectly accurate but it is good enough for your job. Just install the feeler gauge anywhere you want on the piston and cylinder. Measure different combinations. Try the worst scuff on the piston and in the middle of the front or rear of the cylinder. This should be the area of most wear. Then measure somewhere below the rings on the piston around the pin area and and on the cylinder above where the rings stopped their upward stroke. This area is narrow ring, look for it and it becomes obvious. This measurement should be the least wear. I'm not sure of the maximum clearance allowed between the new piston and cylinder but I'd guess three thousanths or just a little less. Use a good ball hone and resurface as little as you can get away with. The cross hatch pattern should be about thirty degrees. If you aren't sure of your assessment skills take it to a shop. I think there is a 50/50 chance you may need a bore and oversized piston.


Piston is definitely scuffed. It looks “light”, not sure if that changes anything. So this means I need a to get it over bored and a new piston? My 0.04 feeler gauge was bent so I used a 0.003. It was snug everywhere except in the middle/top of the front and rear of the cylinder.



Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
48 Posts
Discussion Starter #42 (Edited)
base gasket is held on with rtv sealant ?..this is a big NO NO !!!. I also see scoring on piston and on cylinder wall. I hope you checked your connecting rod for any play where the wrist pin rides ?, as well as any up and down play on the lower rod to crank ?. if there is any play ?, your new top end wont last long at all until you fix the crank/connecting rod !.


There is some rtv on the right far edge of the gasket, underneath the gasket. It’s holding it down/preventing it from moving. No play where the wrist pin rides, no up and down play in the connecting rod.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
48 Posts
Discussion Starter #43
So I need a top end gasket set, over sized piston, cylinder bored, valve seals. Is it 0.20 for the piston? For the cylinder spec do I just add 0.20 to the stock cylinder size?


Sent from my iPhone using Tapatalk
 

·
Super Moderator
Joined
·
36,410 Posts
So I need a top end gasket set, over sized piston, cylinder bored, valve seals. Is it 0.20 for the piston? For the cylinder spec do I just add 0.20 to the stock cylinder size?


Sent from my iPhone using Tapatalk
mic the cylinder, or have a machine shop mic it, compare that reading to the service limits in the service manual ?, see what the next size up is ?, then have the cylinder bored out to match the next size up piston kit :). has this atv been sunk ?. if it has ?, your wasting cash and time until you split the motor, clean it all out, then put it all back together. if you, or it has been sunk ?, AND YOU DO NOT DO THIS ??..YOUR MOTOR WILL NOT LAST !.
 

·
Registered
Joined
·
48 Posts
Discussion Starter #45
So I need a top end gasket set, over sized piston, cylinder bored, valve seals. Is it 0.20 for the piston? For the cylinder spec do I just add 0.20 to the stock cylinder size?





Sent from my iPhone using Tapatalk


mic the cylinder, or have a machine shop mic it, compare that reading to the service limits in the service manual ?, see what the next size up is ?, then have the cylinder bored out to match the next size up piston kit :). has this atv been sunk ?. if it has ?, your wasting cash and time until you split the motor, clean it all out, then put it all back together. if you, or it has been sunk ?, AND YOU DO NOT DO THIS ??..YOUR MOTOR WILL NOT LAST !.

No as stated previously it hasn’t been sunk. I’ll research some piston kits and talk to the machine shop.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
613 Posts
You've come a long way since i last checked this thread and you're doing a great job! You sure you've never done this before?? :)


I don't do engines, but I do know that sealant on the gasket is a "no no", as @shadetree said. Yes, the old gasket needs to be taken off and replaced correctly. Who has worked on this bike in the past and why??
 

·
Registered
Joined
·
48 Posts
Discussion Starter #47
You've come a long way since i last checked this thread and you're doing a great job! You sure you've never done this before?? :)


I don't do engines, but I do know that sealant on the gasket is a "no no", as @shadetree said. Yes, the old gasket needs to be taken off and replaced correctly. Who has worked on this bike in the past and why??


Not sure who worked on it before. We bought it from the Honda dealer used, its an oem piston so not sure what they did. I have rebuilt my other atv’s engine before as well as a few 2S sled engines.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
613 Posts
You've come a long way since i last checked this thread and you're doing a great job! You sure you've never done this before?? :)


I don't do engines, but I do know that sealant on the gasket is a "no no", as @shadetree said. Yes, the old gasket needs to be taken off and replaced correctly. Who has worked on this bike in the past and why??
Not sure who worked on it before. We bought it from the Honda dealer used, its an oem piston so not sure what they did. I have rebuilt my other atv’s engine before as well as a few 2S sled engines.

Okay, that makes more sense that you've done engine work before. LOL


In your post on 7/27/19, the first pic shows side view of the bike with the head cover turned upside down with blue shop towel inside. It may just be the lighting in the pic but it looks to me like the head cover and head are lighter in color than the rest of the engine. I mean, the parts look newer; not as "aged." I can't tell if there is any new sealant that would indicate the cases have been split. How long have you owned it??
 

·
Registered
Joined
·
48 Posts
Discussion Starter #49
You've come a long way since i last checked this thread and you're doing a great job! You sure you've never done this before?? :)


I don't do engines, but I do know that sealant on the gasket is a "no no", as @shadetree said. Yes, the old gasket needs to be taken off and replaced correctly. Who has worked on this bike in the past and why??
Not sure who worked on it before. We bought it from the Honda dealer used, its an oem piston so not sure what they did. I have rebuilt my other atv’s engine before as well as a few 2S sled engines.

Okay, that makes more sense that you've done engine work before. LOL


In your post on 7/27/19, the first pic shows side view of the bike with the head cover turned upside down with blue shop towel inside. It may just be the lighting in the pic but it looks to me like the head cover and head are lighter in color than the rest of the engine. I mean, the parts look newer; not as "aged." I can't tell if there is any new sealant that would indicate the cases have been split. How long have you owned it??


Looks a little lighter to me, hard to say. It might just be because it is less exposed than the crankcase part of the engine. I think we got it in 2013 or 2014, I think there was 4xxx km on it when we bought it. Currently has just under 8000km.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
613 Posts
As I said before, I have a 2014 that I bought used in 2018. Seller swore it had not been sunk but I suspected he was not being truthful. From the looks of your piston it looks like some sand/silt has scored it. I say that based upon pics of other pistons posted here and what the experts have said. So, as @shadetree said, you may go to all this trouble and expense only to find your new top end doesn't last very long because there's still grit and gunk in the engine. I've heard people say they change the oil 3-4 times, run diesel fuel through the engine and other things to "clean it out." I would never bet on any of that.
I'm in the same boat as you. I had the top end rebuilt and cylinder rebored. I finally made the decision not to go to the expense of having the engine split and cleaned. I decided to mount a fire extinguisher on the rear rack and take my chances. LOLLL
 

·
Registered
Joined
·
48 Posts
Discussion Starter #51 (Edited)
As I said before, I have a 2014 that I bought used in 2018. Seller swore it had not been sunk but I suspected he was not being truthful. From the looks of your piston it looks like some sand/silt has scored it. I say that based upon pics of other pistons posted here and what the experts have said. So, as @shadetree said, you may go to all this trouble and expense only to find your new top end doesn't last very long because there's still grit and gunk in the engine. I've heard people say they change the oil 3-4 times, run diesel fuel through the engine and other things to "clean it out." I would never bet on any of that.
I'm in the same boat as you. I had the top end rebuilt and cylinder rebored. I finally made the decision not to go to the expense of having the engine split and cleaned. I decided to mount a fire extinguisher on the rear rack and take my chances. LOLLL


I put on a new air filter on a few weeks ago. I replaced it because the old one was an oem one, likely the original filter. It had a few spots where the foam and rubber was separating, dirt possibly could’ve gotten in maybe that’s what caused the scuffing, but I don’t think so. I think it was because the engine was overheated. I think if dirt had gotten in the engine there would be some more damage to the cylinder head and cylinder though. Usually when you overheat an engine really bad, or in my experience and research at least, it scores/scuffs the cylinder and piston.

As for splitting the cases. I am not doing that. I rebuilt the engine top to bottom on my other atv and it ruined my summer. It would be nice if it was just taking it apart and putting it back together again, but that’s never the case. I’m willing to take the chance. If there was dirt/sand in the engine because someone had sunk it before we bought it that could cause damage, I think it would have done something to the engine in the 5 years I’ve owned it.

When we were interested in buying an atv we asked a salesman to keep an eye out for what we were looking for, they had no used stock that we were interested in at the time. The salesman called us about an atv they had just received in on a trade. They just got it that day so when we went to go look at it, they hadn’t even had a chance to wash it. There was no mud on it at all, no signs cosmetically that it had been abused.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
1,755 Posts
Yes, I don't think there is dirt in the engine either........you put 4000km on it right? It's just worn out. Perhaps it was dirt from the worn air filter, perhaps it was the overheating, perhaps it was poor maintenance from the previous owner. It really doesn't matter at this point. Just have it bored and do the valves. If done properly you may get 10,000km next time.
 

·
Registered
Joined
·
613 Posts
Yes, I don't think there is dirt in the engine either........you put 4000km on it right? It's just worn out. Perhaps it was dirt from the worn air filter, perhaps it was the overheating, perhaps it was poor maintenance from the previous owner. It really doesn't matter at this point. Just have it bored and do the valves. If done properly you may get 10,000km next time.

Okay, I take back what I said. I'm guilty of malpractice as a pseudo-mechanic. :) Now that I know he's owned it 5 years makes a difference. @Flemingo as much as you're ridden this Rancher you would have known by now if there were problems with it initially. Of course, @misterclean59 is correct. He's the man and I value his advice and opinion.
 

·
Super Moderator
Joined
·
36,410 Posts
Yes, I don't think there is dirt in the engine either........you put 4000km on it right? It's just worn out. Perhaps it was dirt from the worn air filter, perhaps it was the overheating, perhaps it was poor maintenance from the previous owner. It really doesn't matter at this point. Just have it bored and do the valves. If done properly you may get 10,000km next time.
and if it was ever sunk ?, he wont get many miles on it..period !. would I take that chance/risk ?..heck no !. money and time don't grow on trees where I come from :).
 

·
Registered
Joined
·
1,755 Posts
Yes, I don't think there is dirt in the engine either........you put 4000km on it right? It's just worn out. Perhaps it was dirt from the worn air filter, perhaps it was the overheating, perhaps it was poor maintenance from the previous owner. It really doesn't matter at this point. Just have it bored and do the valves. If done properly you may get 10,000km next time.
and if it was ever sunk ?, he wont get many miles on it..period !. would I take that chance/risk ?..heck no !. money and time don't grow on trees where I come from :).
He bought it used but put 4000 km on it. If there was dirt in the engine it would have died long ago.
 

·
Registered
Joined
·
48 Posts
Discussion Starter #56
All parts are in. The cylinder and piston were out of spec and the next size up was 0.10 over. Got the cylinder bored and honed. New gasket set with valve seals. New piston kit. New exhaust clamp for muffler to header connection. I don’t have a valve spring compressor so I just got the shop that did the boring to replace the valve seals as well as lap the valves. Getting the cylinder head back tomorrow and will start re-assembly. Going to do an oil change too.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
48 Posts
Discussion Starter #57
Well I didn’t get to the atv as soon as I wanted ha ha. Had some other projects that needed to be done first so the Honda got moved to the bottom of the list. Yesterday I assembled the top end. Got back on it tonight and have the fuel tank and air box tube in. It will either be done tomorrow or the next day. For first start up I plan on turning it over with the spark plug boot off so oil lubes everything up good, then I’ll prime the fuel pump by turning the key on and off a few times.



Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
48 Posts
Discussion Starter #60
It’s running.

Here’s a video of it idling before the rebuild:

Here’s a video of the 3rd startup after the rebuild:

I can’t tell if it sounds different or not? Almost like valve noise? Keep in mind some of the plastics and seat is off so it could just sound different because it is not muffled like it normally is.

Oil level is good. There was no play in the rod bearing and the wrist pin had no play in the rod and the piston. I adjusted the valves and checked my adjustments several times. Adjusted so there was slight pressure on the feeler gauge. Also have a coolant leak on the small hose going from the t stat housing to the water pump. I drained the coolant. Going to take off the line and inspect and replace if needed.


Sent from my iPhone using Tapatalk
 
41 - 60 of 77 Posts
About this Discussion
76 Replies
6 Participants
Flemingo
Honda ATV Forum
We’re a forum community dedicated to Honda ATV owners & enthusiasts. Come join the discussion about upgrades and reliability for your Rancher, Foreman, Recon, FourTrax, Pioneer, and more!
Full Forum Listing
Top