View Full Version : Rings and vavle seals
05DodgeDakota
08-01-2011, 09:48 AM
Hey fellas, I've been lurking on this site for almost a year now but this is my first post. I have a 2008 Honda TRX400ex with roughly 150 HARD hours on it and I'm starting to get some blue smoke in the high RPMs, but I'm not losing power. I've been told it's most likely the rings and/or vavle seals. I'm mechanicly inclinded and would like to do as much of the work myself as I can. I have a couple questions. Can you replace just the rings or do I have to replace the whole piston? So I need to have the clyinder honed or possibly bored? Does anyone have a link to a good write-up with pictures of the replacement? Any other tips? Thanks.
P.S. btw the bike is nearly all stock, just a K&N with prefilter w/no lid, 13 tooth front sprocket, and 150 main, 42 pilot jet and I run Amsoil w/ K&N oil filter.
tri5ron
08-01-2011, 01:39 PM
to answer your question, ...
Yes,... you CAN just replace the rings with a hone job,....
BUT,....
that is ONLY, providing the cylinder is not worn beyond the stock tolerances.
You say it has "150 HARD HOURS".
Chances are, more likely than not, the cylinder is egg shaped and in need of a bore.
The question you need to ask yourself is,...
"If you are going to have the cylinder off, and take it to a machine shop ANYWAY,...
Then why would you go back with the stock piston and compression ?"
Have it bored to a 406, or 416, (this will be determined at the machine shop, when they measure the cylinder).
THEN, buy the corresponding aftermarket piston, and have the shop do the bore job, TO THAT SPECIFIC piston.
Upping the compression to a 10:1 - 10.5:1 ratio, will show you some impressive overall gains in power, and throttle responce,...
WITHOUT creating any significant heat issues,...
AND,... you will still be able to run regular pump gas, (91 - 93 octane).
as well,...
by going to a 406 - 416 with slightly higher compression,...
It will better support, (but not require), other performance improvements, such as a 450r carb, stage 1 or 2 cam, or advanced timing key.
It will run much better and stronger, without significantly compromising any of the reliability, the 400EX is known for.
hope this helps.
(oh, and btw),...
Yeah, do the valve seals while your at it.
they are cheap, and why would you spend the cash to freshen up the cylinder,... without replacing the valve seals at the same time?
(That would be like buying a new set of tires for your truck, and not running the correct air pressure in them).
05DodgeDakota
08-01-2011, 01:48 PM
I'd love to do all that but I'd have to wait longer till I had the money to do all that. But since we are on that topic, what piston kit do you recommend?
tri5ron
08-01-2011, 02:00 PM
You don't necessarily need to do ALL of that right now.
My point is,
you wont truly know, if you need a new piston, until AFTER you have it apart, and have it properly measured.
At THAT point,... you will be able to determine which will be the most cost effective route to take.
IF at that point,
It becomes apparent, that a new piston is in order,...
Then, it only makes since to go to the 406 - 416,
AND,
up he compression to 10:1 - 10.5:1 ratio.
It will still run fine,
(and stronger / better),
with your stock cam, carb, ignition, etc.
In other words,...
If you DO end up needing to replace your piston,....
an aftermarket set-up is nearly the same cost, as a OEM dealer purchased stock piston.
(with a potentially much better performance envelope).
05DodgeDakota
08-01-2011, 02:07 PM
Ok, thank you.
Another question; I had a guy who has a shop take a quick look at it (he quoted me at $400-500 btw) and he said that it would not do any more damage if I continued to ride the quad as is until I have the funds to fix it. Is that a reliable statement?
tri5ron
08-01-2011, 02:14 PM
Uhmm,... that is a rather subjective claim,
relative to an entire host of variables.
but in plain english,
not the most conservative advice.
05DodgeDakota
08-01-2011, 02:24 PM
Originally posted by tri5ron
Uhmm,... that is a rather subjective claim,
relative to an entire host of variables.
but in plain english,
not the most conservative advice.
explain....please
About all that will happen is if you keep riding it, it will smoke more and more and more as the cylinder continues to wear.
In the end you do it right the first time and save yourself the trouble. Might cost more up front that way, but it insures you dont have issues later. This isnt something you can slap a bandaid on and fix-you need to do it right.
05DodgeDakota
08-01-2011, 02:57 PM
Originally posted by CJM
About all that will happen is if you keep riding it, it will smoke more and more and more as the cylinder continues to wear.
In the end you do it right the first time and save yourself the trouble. Might cost more up front that way, but it insures you dont have issues later. This isnt something you can slap a bandaid on and fix-you need to do it right.
That is exactly the way I feel. I want to wait a little while while I save up money to do it right but I also don;t want to stop riding in the meantime. Me and my wife ride about once a week.
hocman123
08-01-2011, 03:34 PM
well if u wait and ride on it i would replace the piston then b/c if all u needed was a hone job u would screw the cylinder up maybe to much but as long as ur good to getting a new piston ride the hell out of it. mine was smoke really bad for months before i redid my topend to the piont if i had a 6-8 hour rideing day i would need to put a quert sometimes more of oil in throught out the day. people said that i was batman with my smoke machine :)
05DodgeDakota
09-07-2011, 10:57 AM
well just an update on the situation. I changed the oil yesterday, used Mobil 1 Racing 4T 10-40w Motorcycle Oil instead of my usual Amsoil Powersports 10w-40 because it's what I had on hand. Anyways, I had more of this flackey black stuff, which I've had some in there before, not sure what it is. But this time I saw some metal shavings as well.
Metal shavings mean something is wearing-metal on metal. Id take it all apart and see wtf is going on.
05DodgeDakota
09-07-2011, 02:34 PM
I'm afraid to take it apart right now because I don;t have the money for the new parts.
Originally posted by 05DodgeDakota
I'm afraid to take it apart right now because I don;t have the money for the new parts.
Running it longer like that could mean failure. Either you park it for now or run it and blow it up-your call.
05DodgeDakota
09-07-2011, 04:39 PM
I know, I know. I'm gonna take it on one more ride this weekend and see if I have any more shavings in the oil. Hopefully Nothing major goes wrong. Famous last words. What do you think would be grinding metal to metal? It's not smoking enough for the rings to be THAT bad. I know my shift fork seems to be rounded off or something, maybe it could be from that?
tri5ron
09-07-2011, 05:47 PM
I think what the message here is,
If you stop riding now, tear it down, and do a proper overhaul,.... It is ONLY going to cost, ..... what it cost's.
VS.
If you continue to ride it now, (obviously a unwise choice), and you blow it up,...
Then there will be a much greater cost in repairs and replacement parts,.... above and beyond what it would take/cost to do it now.
As CJM already said,...
it's your call.
btw, you might want to ask your wife to pack a tow rope with her on your next ride. Sounds to me like there is a good chance you'll be needing it.
jake"08"400
09-07-2011, 10:36 PM
Wow a 08 with only 150 hours and it's already in that bad of shape. What do you do with it haul a freaking bus?
05DodgeDakota
09-08-2011, 05:01 PM
Originally posted by jake"08"400
Wow a 08 with only 150 hours and it's already in that bad of shape. What do you do with it haul a freaking bus?
Probably close to 200 hours by now, but I didn't clean my air filter and change my oil as often as I should have. After I fix this I'm gonna do both after every ride.
matts27
09-08-2011, 05:30 PM
Originally posted by 05DodgeDakota
I had more of this flackey black stuff, which I've had some in there before, not sure what it is. But this time I saw some metal shavings as well.
Sounds like oil carbonizing or breaking down and failing. Metal shavings could be anything, if you're seeing that type of breakdown start by dumping the oil now after every ride to protect the lower end bearings (I prefer the Rotella, plus cheap!). Plan on dropping in a new clutch with the fresh rebuilt motor too, while you're there check the lower end and make sure you clean out as much junk from the motor and oil tank and cooler. Matt
05DodgeDakota
09-08-2011, 05:44 PM
Originally posted by matts27
Sounds like oil carbonizing or breaking down and failing. Metal shavings could be anything, if you're seeing that type of breakdown start by dumping the oil now after every ride to protect the lower end bearings (I prefer the Rotella, plus cheap!). Plan on dropping in a new clutch with the fresh rebuilt motor too, while you're there check the lower end and make sure you clean out as much junk from the motor and oil tank and cooler. Matt
I've been using high quality synthetic oil, would it be doing that? I though it could be seal/gasket material, but I don;t know what I'm looking for. I keep hearing about using rotella diesel oil but I thought that you had to use a motorcycle oil to keep the clutch from slipping? I can't justify dropping in a new clutch unless it needed. I'm not a rich man lol. How do I go about cleaning out the lower end, tank and cooler? Also is there a way once I disassemble the top end to visually inspect the crank bearings for wear?
05DodgeDakota
09-08-2011, 05:49 PM
After talking to a friend, he says he paid only $250 for valves, rings, and hone since he disassembled and reassembled it himself. Never done any thing like this, just simple maintenance on this and my truck. You know, brakes, fluids, filters, plugs, etc. What advice and tips can yall give me to help? I wanna do it right but also get it done before i have to do a whole new piston, etc.
What oil are you using? Alot of oils arent suited for the wet clutch engine setup the EX uses and can ruin the engine/clutch.
As for redoing the topend, it depends on whats exactly wrong. But if the bore itself isnt properly sized anymore your going to need to bore it and go up a size. If you dont its pointless to put ti back together as you will burn oil badly. THis kinda thing needs to be checked by someone with an inside micrometer-most likely a machine shop would do it.
05DodgeDakota
09-09-2011, 04:41 AM
First 3 times I used Amsoil Motorcycle Oil, then I switched to Amsoil Powersports Oil 10w-40, but this time I Used Mobil 1 4T Motorcycle Oil. And I always use either a K&N oil filter or Factory one.
And yes, I was going to disassemble the top end, and Rick Todd Racing was going to do the hone, and spec the cylinder to make sure I don;t need to go up a size. He's also gonna install the rings and seals. Then I have to reassemble the engine.
05DodgeDakota
09-09-2011, 03:32 PM
Another thing I forgot to mention that is probably important. I have alot of Blow-by, or at least I think that is what it is called. What I mean is that the clear, little box attached to the airbox boot has alot of oil in it
powerbomb400
09-09-2011, 04:04 PM
Thats the breather for the crank case. As the crank spins it build pressure inside the case so they vent the pressure into the air vent. It will allow it to equalize the pressure.
05DodgeDakota
09-09-2011, 04:28 PM
Originally posted by powerbomb400
Thats the breather for the crank case. As the crank spins it build pressure inside the case so they vent the pressure into the air vent. It will allow it to equalize the pressure.
yea but I'm getting oil in there. What does that mean?
Mean your rings are bad. Basically what I been saying all along.
http://www.bobistheoilguy.com/blowby.html
This is the possible reason you have metal shavings in the oil-the rings are so worn they are wearing right away. I bet if you were to yank it all apart the piston and cylinder sleeve would look very bad.
I were you: Time to think about boring to the next size cause I guarantee the bore is shot even if you were to put new rings in. 407cc/86mm piston (same thing) is a popular size and means that if the need arises you can rebore for a larger piston later. Boring goes as follows: 402cc/85.5mm, 407cc/86mm, 416cc/87mm, 426/88mm, and 440 (actually 435) or 89mm. 426 is the last time you can bore it, 440 requires a special sleeve.
Figure:
-150 for a piston (id do 10:1 or 11:1 compression)
-boring is between 50-75
-stage 1 cam for 150
-gaskets-I recommend cometic brand MLS gaskets. These are special viton coated (rubberized) gaskets that hold up to extreme use vs even the stock gaskets-never had one fail! Size doesnt matter unless your going 440-otherwise even if its overbored a stock size gasket set will work b/c the piston never comes to the top of the bore in actuality..
Not only will this give you TONS more power, but its reliable. Do note that you will need to run 93 octane or better when you up the compression just to be safe-10:1 is on the borderline, but 11:1 needs it.
Figure my quad (specs in sig) is basically built the same way to a degree, now its not a 450 but it rips, the upside is I dont have to worry about coolant like the 450 and I can be like a tractor and not keep the revs high like a 450 would need to be.
Your call in the end, but its not that costly and will run like a raped ape once done. Dont want to do all that, do a 402 or 407 piston @ 10:1 compression (stock is 9:1) and some gaskets and you will be set.
Pulling the engine apart is super easy, you dont really even need any special tools besides a decent torque wrench. The best advice I can give to you is to NOT overtorque the 8mm bolts that go into the rocker cover/head. They can and will snap-the spec for them is 7 foot pounds. I dont even use a torque wrench, I snug them by hand with a 1/4 drive ratchet.
Hope all that helped...
05DodgeDakota
09-09-2011, 04:53 PM
Originally posted by CJM
Mean your rings are bad. Basically what I been saying all along.
http://www.bobistheoilguy.com/blowby.html
This is the possible reason you have metal shavings in the oil-the rings are so worn they are wearing right away. I bet if you were to yank it all apart the piston and cylinder sleeve would look very bad.
I were you: Time to think about boring to the next size cause I guarantee the bore is shot even if you were to put new rings in. 407cc/86mm piston (same thing) is a popular size and means that if the need arises you can rebore for a larger piston later. Boring goes as follows: 402cc/85.5mm, 407cc/86mm, 416cc/87mm, 426/88mm, and 440 (actually 435) or 89mm. 426 is the last time you can bore it, 440 requires a special sleeve.
Figure:
-150 for a piston (id do 10:1 or 11:1 compression)
-boring is between 50-75
-stage 1 cam for 150
-gaskets-I recommend cometic brand MLS gaskets. These are special viton coated (rubberized) gaskets that hold up to extreme use vs even the stock gaskets-never had one fail! Size doesnt matter unless your going 440-otherwise even if its overbored a stock size gasket set will work b/c the piston never comes to the top of the bore in actuality..
Not only will this give you TONS more power, but its reliable. Do note that you will need to run 93 octane or better when you up the compression just to be safe-10:1 is on the borderline, but 11:1 needs it.
Figure my quad (specs in sig) is basically built the same way to a degree, now its not a 450 but it rips, the upside is I dont have to worry about coolant like the 450 and I can be like a tractor and not keep the revs high like a 450 would need to be.
Your call in the end, but its not that costly and will run like a raped ape once done. Dont want to do all that, do a 402 or 407 piston @ 10:1 compression (stock is 9:1) and some gaskets and you will be set.
Pulling the engine apart is super easy, you dont really even need any special tools besides a decent torque wrench. The best advice I can give to you is to NOT overtorque the 8mm bolts that go into the rocker cover/head. They can and will snap-the spec for them is 7 foot pounds. I dont even use a torque wrench, I snug them by hand with a 1/4 drive ratchet.
Hope all that helped...
it does, thank you. I just thought it would be smoking ALOT more than it is. I only get alittle smoke in the high rpms. I figured if the ringss were that bad that it would be constantly somking, ya know? I'm looking at parts, etc online now.
Some more questions:
Do I need to replace the cam chain?
Do I need new head studs?
Is it okay to run a higher comp piston on a stock exhaust?
With a higher comp piston do I need to add some cooling mods?
Also gonna go ahead and replace my airfilter. Gonna go with a clamp on conversion, but I'm torn between a UNI and another K&N...
05DodgeDakota
09-09-2011, 04:59 PM
I'm gonna do a compression test before I tear down the motor, and I'm gonna go cut open my oil filter to have a look see and see if I can smell gas in my old oil..
Comp test is a good idea, but understand it isnt always accurate-a leak down test is.
Funny thing is I just checked mineout and everything appeared to be fine-except the rings are out of spec and so is the bore (only slightly) However it made EXCELLENT compression funny enough..
05DodgeDakota
09-09-2011, 06:48 PM
Originally posted by CJM
Comp test is a good idea, but understand it isnt always accurate-a leak down test is.
Funny thing is I just checked mineout and everything appeared to be fine-except the rings are out of spec and so is the bore (only slightly) However it made EXCELLENT compression funny enough..
what a leak down test?
This will explain it better than I can: http://en.wikipedia.org/wiki/Leak-down_tester
Basically it measures to see if the cylinder, valves, etc will hold pressure. It doesnt hold pressure then something isnt sealing right.
05DodgeDakota
09-10-2011, 03:58 AM
Originally posted by CJM
This will explain it better than I can: http://en.wikipedia.org/wiki/Leak-down_tester
Basically it measures to see if the cylinder, valves, etc will hold pressure. It doesnt hold pressure then something isnt sealing right.
Okay, thank you once again.
05DodgeDakota
09-10-2011, 04:14 AM
Wanted to ask something again, becasue I think you missed the post eariler:
Some more questions:
Do I need to replace the cam chain?
Do I need new head studs?
Is it okay to run a higher comp piston on a stock exhaust?
With a higher comp piston do I need to add some cooling mods?
Also gonna go ahead and replace my airfilter. Gonna go with a clamp on conversion, but I'm torn between a UNI and another K&N...
Replacing the cam chain is usually a good idea, one off a 02-06 CRF450 will fit. its stronger and cheaper.
head studs arent needed really, at 11:1 compression it is a good idea b/c the exhaust side studs can pull out due to the heat created if your jetting is off.
Stock is exhaust is restrictive, but its ok to run it onhigher higher compression setup. A slip on would be a good idea.
No cooling mods are really needed if you jet it properly.
KN imho is junk, it lets fine particles in unless you use a prefilter like an outwears-which defeats the purpose. I use a uni and have been very happy, it filters better than a KN.
Powered by vBulletin® Version 4.2.1 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.