Seems there has been a rash of honda pilot main bearing failures in the past couple of years. Don't know what it is related to, but here are a few choiced to pick from.

Most of the bearing failures occured in pilots with powerbloc clutches.....clutch problem???

Most were running AmsOil mixed roughly 32:1......oil problem??

All were using stock HONDA bearings.....bearing problem??


I was looking and noticed a few things.

1. the honda part number for the FL400 main bearing is 91033-HE0-005 and lists for $26 on service honda's website. (its really a 6306)

2. the honda part number for the FL 250 crank bearing is 91030-950-003 and lists for $23 on service honda's website. (hey guess what this is a 6306 too!)

3. The same 6306 bearing from boss bearing http://www.bossbearing.com/z.asp?ID=214 is $14.00.

4. The 6306 bearing from ESI is $12.00 http://bearingsdirect.com/cgi-bin/autocart.cgi?CAT=10

These bearings are the SAME, all bear the 6306 bearing part number!!!! Since the HONDA bearings have been having a high failure rate of late, why would anyone keep using a KNOWN faulty part???

This is just an observation. There are different "grades" of bearing available meaning their tolerances are better from one grade to the next, but looks like honda has certainly dropped the ball.

don't forget that the 6306 bearing is a 6306 C3 bearing, it is not the same as a
plain 6306, you could be onto something with the ideas you listed this is why
I sent the failed bearings for Lee to look at, he seem to think it was a lube problem,
I found all mine to have plenty of oil in the bottom end after the poofkaboom
and the Engine was taken apart, look at the amount of oil that is clinging to the
crank lobes of Pilotnut's crank you can see it in the pics
http://pilotodyssey.com/PO/viewtopic.php?t=1111 that does not mean at a
certain rpm there is a loss of lube in the bottom end, I always found plenty of oil
in the bottom end each time I had taken my Engine apart for rebuild but my Engine
was usually idled on the trailer at the end of a riding trip then rode from the trailer
to the shop and taken apart, one year I took my Pilot for a WOT (Wide Open Throttle) 1.5 mile run
then killed the Engine and pushed it into the shop, found a whole lot less oil in
the bottom end then... That should have been a clue?

You read this? http://pilotodyssey.com/PO/viewtopic.php?t=1099

The only solution I have come up with so far would be to add a
double row bearing by boring out the case then fabricating a
bearing holder and welding it into the cases or undercutting the
web of the crank shaft, removing the bearing from the crank
in the future would be a real bitch if I take this route, since
I installed a 440 in my Pilot it gives me time to work on the
problem, I remember seeing balance washers pop riveted on
my original or first PB clutch I don't recall if they have them on
my new ones, one would think since PB designs and builds
clutches for a living and has done so for many years that they
would be balanced quite well. I have never been able to
get a reply from them by email perhaps some French speaking
Canadian could call them on the phone and ask?

Another solution would be for me to change my crank bearings every
other year as a maintenance item like changing the piston.

even with the c3 specification the bearings I have found are a lot cheaper than even service honda prices! I know the links are for european pricing, but I bet a phone call to one of the many bearing houses will confirm that most stock the C3 as a standard grade. I have also inculded a couple articles which indicate what the "C3" rating means.

http://www.engineeringtalk.com/news/nsk/nsk132.html

http://www.ahrinternational.com/bearing ... lained.htm

http://www.bandcexpress.co.uk/cgi-bin/b ... BE-KOYOMTN

http://www.dirtbikestore.co.uk/acatalog ... gs_40.html

I know what C3 means I learned this many years ago when I was a industrial
maintenance apprentice, Don and MacDizzy both told me the importance of
the bearing that is installed having the C3 stamped on the bearing if it is not
there then who actually knows, I have found the C3 bearing for less than 1/2
of what hillside charges, they come from china, I rather just buy them from
Honda whilst I am placing my order, my experience in my life time with
something that says "made in china" is the stuff is junk and for the most
part they make look a like stuff hehe, Years ago someone told me that
vendors that supply parts to Honda are held to a higher standard than
the same product being shipped to lets say auto zone , walmart, NAPA...
Until I can get more or better advice on what bearing to use I am going
to stick with the ones I get from Honda, I have asked on many tech msg
boards about bearings and didnt get much, guys going to the ceramic
bearings are doing so to reduce friction and increase HP has nothing to
do with wear and tear they don't know if they last longer or not.

Thanks for the info and the links I would like to get something better and find
out more about the bearings we are using, I know your a good researcher
when it comes to things like this, my gut feeling is still we are
exceeding the design loads, then by raising the RPM levels we are making it
turn more RPM's than it was with stock clutch settings, the bearing takes alot
abuse when your stretching belts at WOT (Wide Open Throttle).

I wish Honda would have installed 2 bearings like on my ROTAX over the
years it would have probably saved me a few grand...

Please find us something better!

I believe that the Pilots with bad bearings also had

1) ALOT (<--lmao) more hp than stock

2) Ran/run more rpm than stock

In those articals they state vibration and noise (harmonics?) issues, would they not change or be influenced under these conditions?

Adding 50% to 100% more power to something designed to handle much less is a huge factor, is it not?

If we expect shorter life with high performance thrown in from our pistons, rings, bore's and rods shouldn't we expect a much shorter life of the one thing that excepts and transfers all the increase in power?

Imagine what the increase of piston speed does for the bearings alone, baring the above "key" points?

What about increased torque from the increase in power? Torsion?

Maybe the most important thing to think about is that we know with high performance there is a cost in reliability, taking a Engine and increasing or even doubling it's power output is going to take it's toll. I think even an engineer would have to "guess" on if a C2 or C1 bearing would add longevity to our motors, taking the heat, vibration and noise into the equasion. Wouldn't it have to be designed on a "per motor (( Internal Combustion Engine ? ))" basis? Would the engineers at Honda have added a second bearing at either end knowing they would be in the 50 to 60 hp range? Is there a one size fits all ball bearing? If so would Honda have used it?

Things that make you go hmmm!

My research on the ceramic bearings is this. The bearing balls are HARDER Harder = less ball deflection under load. They are more temperature stable. More stable = less ball diameter change. I have an email into the engineering department of one company and will post that reply when I get it. I do not doubt that you are a die hard honda guy, but when there have been no fewer than 6 sets of main bearing failures in the last year its time to find a better mouse trap. Whether its the ball seperators failing, or the bearing balls failing, its time to try a different approach.
Maybe its time to switch oils, maybe clutches, maybe bearings. But with the current failure rate of bearings why keep going with a KNOWN faulty product? China is not the only place that makes bearings, and neither is honda. There a multitude of bearing manufacturers out there all with varying degrees of quality.

"There a multitude of bearing manufacturers out there all with varying degrees of quality."

Right but to date nobody can tell me the bearing they want to sell me is better than what
I buy from Honda, feed back I have so far is all a gut feeling and a lot of brand loyalty,
my conclusion is for my Engine mods and the way I use my Engine that I need to change
my bearings at least every other season, I probably need to at the least take the rod
out and change the big end pin and bearing.

Let us know what that guys says and soon, Pilotnut needs to figure out what he is
going to use on his Pilot.

Ceramic might be the way to go, since there is less dimensional changed who will
set the clearance for our Engine? What brand do we use, cost?

I'll let you know as soon as I can. In the mean time here is the NACHI bearing that honda uses. Same part number and a C3 specification for less than 9 bucks each!

http://www.awbearings.com/awbearings/db ... &Product=B

here is a better page for you...looks like nachi is the cheap one of the bunch???Maybe the others are better?

http://www.awbearings.com/awbearings/di ... t=B&page=5

I wouldn't recommend retrofitting to ceramic bearings for this application. It has been my experience with superchargers that ceramic bearings just don't last and are extremley fragile when it comes to installation. Of course blowers run up to 65,000rpm but they don't have the heat of combustion along with the debris that would be sucked into the Engine from normal use like the pilot Engine would. Is it possible that the oil went right out the aftermarket pipe/silencer that most guys run. With less backpressure as a result of better cylinder scavenging I could see the oil (at a higher rpm) going right out the exhaust causing a lube problem for the mains.

I think unless you have a spare set of cases, crank, etc. to throw away, you would be a fool to use anything other than the honda main bearings. You don't use wally world oil why use wally world bearings, any engineer can say this meets blah blah abllah blah, we all seen how that works.

Sure there may be a problem but grabing a 6306 from your local bearing shop is not the answer.

For a set of wheel bearings sure who cares but not a temperature sensitive, critically engineered setting. Much more detail should be documented to compare the failures beyond saying most guys run amsoil 50:1, before attempting to use another bearing. If anything find a different motorcycle crank bearing, say one for a yamaha or Suzuki main bearings or something and use that to test.

I used to go thru a lot of 2 stroke motors, never did i have a main bearing failure that was not contributable to some external force and not the actual bearing itself, I can't think of one. Be it lack of oil at one point in time (maybe not exactly when it let go or seized), something else coming loose, heat, water/coolant in lower end, it was always something.

I have had my pilot for 5 years and replaced my mains once and only because I had to rebuild my crank bc the lower rod bearing heat seize (lack of oil/little lean on top, airbox lid off) from a super long over extended donut session at Glamis, i rode it until it started to sieze and backed off, then rode it the next day until it let loose, about 2 hours more.
The mains looked great even with the rod taking a shit from lack of oil and me still running it til she wouldn't run no more. I contribute my pilot running good to good fuel/oil, usually rich jetting, gentle warm ups and a total lack of time to do any mods. I think theres something to that PB clutch thing possibly combined with the HP mods, either / or could be likely, i got rid of both my PB clutches without installing either one and bought a spare used stock clutch instead. If PB couldn't get the clutch faces smooth how could they balance them? skeered me away ...

I would be very interested in a chart that shows what oil, fuel, ratio, jetting, aftermarket products (clutch, HP mods), time and whatever else guys can think of with type of failure. but not interested enough to do anything about it, my shit runs good.


Who wants to be the Aftermarket Bearing Test Dummy?

Pilothawk ?

Hare, I havent check them all but here here is one PB cover with a balance
washer on the cover, I know I have seen this on another one of my PB
clutches, I will have to inspect the newer clutches I got from Ludedude
to verify they have some sort of balance mod to them, whether it be
added weight or removed weight by machining or drilling, I ASSume
they do balance them, PB has been making OEM clutches since the
early 70's (perhaps longer?) then again the new clutches I have were
made by IBC, IBC bought out PB...

I wont install a bearing other than what I get from Honda unless I can get a
good reason to do so first, I drive to long and spend to much money on
gas to get to a riding are only to find out another bearing brand might not
be as good, for me, under my conditions, I have come to the conclusion I
need to replace my bearings every other season, the cost for me to replace
the bearings during a annual top end inspection would be less than it cost me
to drive 250 miles in my MH .

How do you balance a clutch or to check to see if it is balanced? or to compare to stock

would be nice to try to eliminate factors

judging by feel the PB weighs considerable less than the stock clutch wonder what the actual difference is, looks like the weight is closer in on the PB as well.

I have no idea how to check the balance on a clutch, I don't know what the weight
difference is I know the PB 'feels' less than the Honda, since I was changing it out
to something adjustable weight was not a big deal, I was told by a few of the old
250 and 350 race guys the PB weighs less than the Comet 102 and the Engine would
rev out faster with the PB, again I never really cared it just came up in conversation
I had seen to many of the 102's with rusted up worn out pins, rollers and ramps to
know I need to avoid the maintenance problems wiht that clutch, the stock Honda
has about a pound (guessing) of thin grease inside for lube you think with the clutch
spining the grease at 7400 RPM will affect the balance? Make it balanced? If I ever install
the stock clutch again I was going to remove all the grease , then lube the rollers and
slides with comet clutch lube ( to save weight, rev faster) since it is sealed I bet a
guy could get by with a once a season lube and check...



So... How do we check the balance so we can rule balance out?

I tend to think a lot of the problem has basically been said already. With the additional hp being added along with quicker higher rpm's being turned,clutches that wiegh less than original stock components,better belts and tires (better traction)and maybe even driven clutch mods would all greatly affect the wear and tear from the stock specs.

someone could call pb or the new company and see what they have to say or one could take an old crankshaft ,cut off the clutch side snout so it is mountable to the clutch and a rotating tire balancer(may have to make a mount plate/which may intale more balancing)and check the balance that way.I would think though checking the balance of the clutches would have to or should be checked in three stages.Full closed(idle),half open(mid throttle) and full open(WOT (Wide Open Throttle))to verify that it is balanced all the way thru it's cycle.If someone has a friend that does tire work that may be the easiest way to go.

With most new found hp and mods to these machines it may be better to go to say a 24:1 mix ?

i tend to think it may not be an oil issue but rather a quicker higher rpm range that may be rattiling those bearing cages loose and eventually letting go of the loose rivets which werent capable of the higher loads and vibration they are now seeing.

What does lee think of the new over stock loads that are being put on these machines now,compared to what honda had installed for stock specs?

Balancing could be done at an automotive machine shop. They balance crankshafts and flywheels on a regular basis. I would question the accuracy of the tire machine for balancing in this application. If you have the crank out, install the factory flywheel and then compare both the pb to the oem clutch and see where the weight differences are. I can't blelieve you guys run them at 50:1. I've always run all my 2 cycles at 32:1 and have never ever lost a 2 cycle Engine, top end and bottom end, ever. That goes back 15yrs. Now that I have just jinxed myself I'll shut up.

most of us run them (with good oil) at 32:1,pilots,fl350's and fl250's.Though even Ed out at EEE has told me sometimes he runs them at 40:1

I run all mine at 32:1 even me snowmobile engines are run at 32:1

guess because it says honda its better. Lee has already said that they pull bearings off the shelf that suit their needs. Just so happenes that honda has a big contract with nachi or even own part of nachi???? The bearing IS a 6306 C3 nothing more nothing less.

Bearings are taking a shit more than any of us think they should. You are risking a bottom end continuing to run them. The sites I have listed above do carry the nachi c3 bearing for less than half the cost of the "honda" nachi bearing, to quote hoser...."WHY PAY MORE" Out of 6 bearing manufacturers the nachi was the 2nd lowest cost. Does that mean anything.

Come on guys. open your eyes.

LMAO you have some sort of proof that bearings are just bearings so buy the cheap ones,
if you do please share this with me, I am lost here so please explain.

Are you telling me if I go to the link you provided and buy the most expensive bearing they
have it will be better and last longer than the nachi bearings? Myself I am looking for some
sort of tech info not a hunch based on a price list like youprovided, follow me? You for
some reason, almost seem fixated or focused on just the price, that's ok with me do
what you want, buy what you want, myself I am looking for a better bearing, my focus
is on a better bearing not a better price, I knew about better prices on bearings long
before I met you, I got friends that have indrustrial discounts to bearings, my wife
can get me bearings at her companys cost, both have over the years got me bearings
for my 3 wheelers, tractors, trucks, cars etc, now if I can find some sort of technical data
that says another bearing is better than another and that bearing ends up costing less
then so be it, again my focus here on this subject is hard data or facts that one bearing
is better than another.

DC provided me with a contact to get some bearing data from, I will type something up and
submit it to him and see what he says, again I am looking for some sort of engineering
data or better yet actual test data not sales hype or hype from someone that is loyal to a
brand, the loyality I have is based on bearings I have used in the past, I know what to
expect out of the bearings I am buying currently, good or bad that is worth alot to me.

Any questions you want me to ask him?

What replies you get from the emails you sent, what questions did you ask?

Lets all try to keep the focus on facts that support a better bearing then we can
seek out a good price.

I would like to revisit this topic in hopes to clarify the whole topic of Pilot crank bearing failures.

I recently was notified by a few of our 'brightside' members that certain darkside members seem to be totally confused on these bearing failures that are documented on my site, by following the darkside manual page one section TWO "blame hoser" it seems they have done just that they are blaming hoser for all Pilot crank bearing failures, it seems they are too dumb or too lazy to read, understand and study the FACTS about Pilot crank bearing failures, they are using the crank bearings as another darkside bomb to SMEAR my good name and to diminish all the GOOD I have done for the Pilot Odyssey community.

People who know me know I like FACTS so lets look at FACTS and NOT listen to darkside comments made by people that don't, havent, cant wrench on Pilot engines.

So lets collect the FACTS and analyze them and dispel any myths being spewed to all the new guys by the darkside, EVERYBODY can benefit from knowing the facts.

I have started a new page Pilot Crank bearings to hopefully document ALL Pilot crank bearing failures, since PilotOdyssey.com was born and raised as a interactive site I need help to finish this page and discuss and find a cure for the crank bearing failures.

So what pilot crank bearing failures have I forgot to add to this page? http://pilotodyssey.com/pilotcrankbearings.htm

I am looking for my Pilots first bearing failure, it was right after I installed my MacDizzy ported top end, they were the bearings installed by HONDA...

I can be the test dummy-I recently purchased a set of crank bearings for my 350 motor (( Internal Combustion Engine ? )) Hoser is rebuilding me for:

http://pilotodyssey.com/PO/viewtopic.php?t=3596

As you can see in the thread-the bearings arent Honda OEM and they are not stamped 6306,C3 nothing.These bearings were purchased from Triple EEE racing in California and have yet to be installed by Hoser.I am sure he can shed more light on them from his CSI of them already posted.We can learn much from them if indeed they Poofkaboom in this Engine.They also have grease in them as well- which Ed has told me to leave inside them , no cleaning them out during installation.This also can be debated as too why? grease should be left inside these bearing? -for initial start-up?WILL THE GREASE BE BROKEN DOWN DURING BREAK IN PERIOD FOR THE motor (( Internal Combustion Engine ? )),without the grease do the bearings suffer from heat related stress due to lack of lubrication?Good questions I say-what do you guys think?

The grease will be completely gone in a few short minutes.

Gob of grease stuck to the plug?

Ever take a greased bearing and try to wash it with gas lol, I have, this is why I think they need cleaned before installing into a Engine but I will install greased as directed.

I agree, also better for heat transfer,and constant fresh oil change.