What happened to Isabella's Engine?

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hppants

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In case you haven’t heard about Isabella, the FJR used by fellow member Patriot, please refer to this thread:

https://www.fjrforum.com/forum//index.php/topic/150618-running-bad-feeling-blessedlimped-home-walking-on-air/

The rest of us recall that I volunteered to take the grenaded motor apart to learn more about what happened to it. All parts from this motor will be gladly given to any forum member for only the cost of shipping. A separate thread will be started on that after the motor is apart.

A little background on this engine:

Patriot tells me that this bike is an ’04 with 169K miles at the time of motor failure. However, this is not the first motor in the bike. This motor was installed about 75K miles ago, and had 20K miles on it when installed (95K miles total). About 20K miles ago, the cylinder head was re-built because of a burnt #4 exhaust valve. Seems he crushed the #4 exhaust pipe and rode with it like that for about 15K.

The motorcycle mechanic that worked on Patriot’s bike diagnosed a bad #3 rod bearing.

April 13, 2013

I got started on the disassembly today.

fjrmotor1_zpsa1bcabc8.jpg


I’m just about to split the cases.

fjrmotor8_zps26cd99a0.jpg


I’m amazed at how stout this motor is built. Check out the size of the output shaft gears

fjrmotor5_zpse46784da.jpg


Also worth mentioning is how little wear this engine is showing. The camshafts have no wear on the lobes

fjrmotor7_zps28d7d903.jpg


You can still see most of the hone marks on the cylinders for a motor with almost 100K on it.

fjrmotor6_zpse17683a6.jpg


Looks like the clutch basket could go forever – Patriot tells me that the clutch is original. Also, the clutch plates (metal) had zero burn marks on them and were completely flat. Back in my dirt bike days, we would have re-used these plates no questions asked. The clutch friction disks were getting pretty thin, but still had some life left in it.

fjrmotor2_zpsfc42cfe4.jpg


The cam chain was very tight and the adjuster had well over ½ of it’s travel left. The adjuster on Patriot’s bike had the “blue dot” on it. I think that is a good sign?

fjrmotor4_zps658b6a83.jpg


I have a couple questions for the mechanics among us.

1. Which direction does the rotor nut (pictured below) loosen (clockwise or counterclockwise)? I put 125 psi on my impact wrench on that baby and it won’t budge. Any thoughts?

2. As you can see, I've removed the clutch pressure plate and friction disks. Does the clutch basket just pull out? I can wiggle it a tad, but it won't ride all the way out of the splined shaft.

I'm enjoying this experience and opportunity to learn more about our bikes. More later….

 
Assume you are talking the Generator rotor bolt? No mention of reversed threads on that. The tightening spec is 94 ft-lbs. Probably need to hold the rotor from turning somehow.

 
I think this is the thread that wfoo' is referring to. The puller that was finally successful can be rented or some places would even just loan the tool to you.

The rotor is a hard pull (evidently so is the bolt). It is easy to damage the magnetic rotor so you need to take some care in removing it. Once you get a puller on the rotor and get some force on it you can put a piece of hard wood on the rotor and tap it with a hammer around the circumference then apply a little more force, repeat. The tapping can help a taper fit part pop free.

My impact wrench generally buzzes bolts and stuck nuts right off. If you continue to have problems with the rotor nut/bolt try tightening it a small amount then in the unbolt direction. This little trick usually works on hard stuck parts.

 
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this is so cool...

re: clutch wear; yes, my throttle control skills suck...albeit, I use the clutch friction point instead

that's me pulling out from a stop with the engine at 3-4k rpm the the clutch feathering like a muddapuckka

I wish I had let you take my service manual...you are welcome to it...I haven't looked at it for years now that I'm comfortable doing the basics and have the forum to fall back on...only Aaron has opened it and appreciates my bringing it with the bike

 
Oops - I fogot to attach the picture of the "rotor", which is the term I use to describe the device that creates the magnetic field so that the stator can make electricity.

fjrmotor3_zps47264271.jpg


 
I tried to hunk in both directions with my impact wrench (1/2 in drive, 125+ psi), but it wont' budge. I'll keep trying.

I have a puller like the one depicted in the referenced thread. That's no problem once I get the bolt off.

 
Interesting.. My bolt came right out.. 90 psi and impact.

Wonder if someone used red loctite on it at some point in time?

Great thread, hippopants, keep it up!

:rofl:

 
Wonder how the mechanic determined this motor had a bad #3 rod bearing without splitting the case and getting to the lower end?

 
Hornet - this was my question too. Some of you may recall that Redfish Hunter and I accompanied Patriot to pick up his bike from the mechanic. When I asked Aaron (the mechanic) how he knew the rod bearing was gone, he told me that they used a stethescope on the running motor to determine it was somewhere in the bottom end. Then they pulled the spark plugs and rotated the engine while sticking a metal rod on top of the piston. Because the #3 piston had some play (up and down) in it, they deduced the rod bearing was bad. I guess we will know soon enough.

Anyone have any words of widsom for my clutch basket question?

 
Would you mind doing a dissection on the oil filter? Kinda curious if an oil flow issue lead to bearing failure.

 
Seriously now,I can't believe that an fjr engine can cause a like this damage itself..!

Something caused this damage!But..what..??

 
Would you mind doing a dissection on the oil filter? Kinda curious if an oil flow issue lead to bearing failure.
Not from that filter, it's a Purolator Pure One 14610. Same 14 psi pressure rating for the bypass as the Yamaha filter, IIRC.

Never the less, it would be interesting to see how much bearing crap it caught.

 
When I asked Aaron (the mechanic) how he knew the rod bearing was gone, he told me that they used a stethescope on the running motor to determine it was somewhere in the bottom end. Then they pulled the spark plugs and rotated the engine while sticking a metal rod on top of the piston. Because the #3 piston had some play (up and down) in it, they deduced the rod bearing was bad. I guess we will know soon enough.
This sure sounds like a good way to tell if a rod (bearing) is shot. It will not tell you if it is the big or small end of the rod, but there should be no piston movement without crankshaft movement.

That is all you would need to know. No need to open it up[ except for curiosity sake, and I don't think a pro mechanic would be curious enough to waste several more hours of uncompensated labor in the quest for that kind of knowledge. ;)

 

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