Took the pilot out last weekend and while I was riding around I heard a weird winding sound coming from the Engine and shut her down. The noise sounded like a bearing was going bad. I had to start the Engine again due to the fact I was in an area I couldn't tow the pilot out with my truck. I started the Engine and noise came back for about 10-20 seconds and the noise went away...Weird...

Checked the spark plug and it was clean with no metal debris.. Checked compression and it read at 145psi... I did a top end rebuild about a year ago and I recently had the cylinder rehoned, replaced the clutch side crank seal and put on new piston rings. Since I've owned the pilot, I've never done a low end rebuild.

Now is a good time to do it....

Might have found a potential problem... I think I may have pushed in the crank seal too far and not flush with the case. Could this severely damage the bearing??

did you csi the clutch belt gaurd or anything that might have come lose or could have TEMPORARILY have caused the noise???

Good question Turbotexas. I had the belt guard taken off while I was riding it when the noise happened. I've heard odd sounds hear and there which turned out to twigs or debris stuck under the pilot but this was a sound I could hear with my helmet on to the point I had to stop because I was freaked out about what the hell was going on.

This happened to me with my triple e... I had the pipe fall apart on me, and the previous owner had chicken wired the clutch gaurd to this same pipe... So when it broke the clutch gaurd and it dropped onto the clutches... you can imagine my reaction!!! I freaked and shut off the key...

I would have pissed my pants if that would have happened to me.....

Pics of crank bearing after I removed the crank seal... Looks like I pushed the crank seal in way too far where the seal was definitely rubbing against the bearing and made a somewhat looking burn mark on the inner race of the bearing... Would this cause the sound I heard??

By chance did you remove the belt to make sure it was coming from the Engine and not the trans.

I didn't get a chance to take the belt off when the noise started. By the time I shut the Engine down and restart it again, the noise only came back for about 10-20 seconds and couldn't tell if it was coming from the Engine or the transmission. I couldn't get the noise to come back again...

what kind of clutches do you have?
I don't see the seal rubbing on the bearings making that much noise???

Stock clutches...

Does the bearing look like it's been worn with the seal pressed up on it?

take the stock clutch and shake it around...

BUT we have to have someone with a stock clutch to do the same to see if there is something loose in there...

What's the belt look like?

The first pilot belt I shredded made an odd whining grinding noise before it finally failed. The noise was off and on for more than an hour and was unpredictable.

I have a spare stock clutch I got from FrankO, it makes no noise when shaken.......

The belt is in good condition and not even a year old. I shook the clutch around and all I can hear is the pucks moving around which I assume is normal??

Update....


I finally have all the tools I need to separate the cases and remove the flywheel.... I'll post pics when I do it.

I ordered new seals, bearings etc. to rebuild the lower end which a majority of the parts were ordered through Service Honda. I received the parts yesterday and I found one of crank bearings is defective. I hold the bearing with my fingers through the inside of the bearing, spin it and I feel and hear a ticking sound out of the bearing. I checked the other bearing and it's perfectly smooth.

I know hoser had some serious issues with defective bearings but is this problem still going on with defective oem bearings? Has this happened to anyone else???

Update:

I split the cases and might have found a problem with a main bearing.

The bearing in the pics has inconsistent marks in between the inner and outer race. It almost looks like burn marks as if the bearing seized.
There is also play between the outer and inner race. If I grab the outer race, I make it wiggle a little bit.

Looking at the crank case, it looks as though the outer race of the bearing slipped in the case.... Possible seizure??

If the bearing did seize, what would cause this? The Engine wasn't running lean and there wasn't an air leak...

That crankcase def looks normal man...doesnt look like it spun a bearing. Although the cage in that main bearing is awfuly purple. Just a ? What is the discoloration on your crank? Did the machine sit? Or did you have a tank of gross fuel at any point? How old is that bottom end? Original? There sure looks to be the start of a hot spot on the edge of that piston...how is your jetting? Did the rubber on the seals (The Ignition side that had not been replaced) look dry and cracked or was there a thin spring on the mag side of the crank when you disassembled it?

don't want to bomb you with a million questions at once but... :) did you by chance grab hold of the clutch when the Engine was mounted in the chassis and clunk it up and down to check for any wiggle? That gives you a huge handle on which to check for main bearing play...because that focker looks played out from the pics. What kind of pre mix oil are you using and how bad is the ethanol in your pump fuel? If you are using it. 81.5 mm Wiseco top end ?

Cases look normal you have the bearings off the crank?

Some of the color you see on the bearings is normal its from the gas oil mix almost like a varnish take some carb or brake cleaner and try to wash it off see what happens kinda wondering if their is any discoloring of the metal like it got hot myself.

The more questions the better... I'm assuming the discoloration of the crank was the previous owner letting it sit too long without fogging the Engine periodically.

I've owned the pilot for two years and this is first time I've done a low end rebuild. The previous owner wasn't the sharpest tool in the shed so who knows long the low end has been rebuilt...

The jetting is okay with plug chops that I occasionally do.. The right crank seal was in good condition and the spring was intact. Before I removed the Engine I did grab the clutch to see if there was any play and there wasn't; although, the left crank bearing that stuck on the crank does have a considerable amount of play in it. The piston is a wiseco 81.5 mm.

Waiting for a puller tool to properly remove the crank bearing. I tried cleaning the bearing off with carb cleaner the discoloration didn't come off.. BTW the bearing has a decent amount of play in it between the inner and outer race...

My best suggestion is to CSI that purple cage main bearing first. Take a good look at the race surfaces. (you can see them by looking in the side with a flashlight) You are prob going to see some pitting or gauling if that bearing was bad. If you don't find any conclusive evidence...keep your CSI cap on and keep inspecting. Every bearing...every gear face. You would be surprised how little of an inperfection would cause a funky noise. But usually is more of a knocking than a screeching or squealing. Main bearings usually make more of a constant growl when they are pitted. If it were to have been your problem you may find some significant flat spots on the ball bearings during your CSI...but with all that force you probably would have had your Pilot stall or lock up. Has that ever happened?

Sinced I've owned the pilot for two years, the noise has never happened. Like I had mention before the guy who I bought the pilot from didn't know what the hell he was doing with it. I feel better rebuilding the low end myself knowing I'm giving the Engine a fresh rebuild...

Update:

Well I put everything together, pressure and compression tested the Engine and so far everything looked good. So I finally took it out and after doing some break-in heat cycles, it ran like a champ.. Below is what I replaced/rebuilt:

-Crank Brarings
-Rebuilt Crank w/Vesrah Rod
-All New Gaskets
-New Crank Oil Seals
-New R Crankcase Oil Seal
-New Mechanical Seal-Water Pump
-New Oil Seal: Water Pump
-All Dowels Replaced
-New O-rings
-New Radiator Hoses thanks to afastcar