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I missed 2nd gear and revved past 12k, now i've got a new sound...

Started by motorider17, June 12, 2017, 12:04:57 PM

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motorider17

Hi. I have a Yamaha FJ1100 from 1984. It has around 65k miles on the clock.
Going from first to second in high revs have always taken a little extra effort. I've missed a couple of times before and revved past redline, but today I really made it. The bike was of course fully warmed up, anyway when shifting to second I missed and revved the hell out of the engine past 12k for a sec or two. After this i retried second gear and the bike made horrible crunching sounds. I stopped and had a look around and under the bike. No leaks. I was immediately sure that I had blown the engine. Anyway, it idles like before with no unnormal noises, but it's still making this crunching sound under moderate load going uphill. So I carefully went on the last 5 miles to get home, and have been testing the bike a little. I put it on the center stand and load the engine with the rear brake, with no abnormal noises. As soon as I get on the bike and ride I hear this crunching sound, kind of like the sound a car makes when you ride your car on gravel and gravel is hitting your wheel arches. So now I've parked the bike and i plan to do an oil change as I believe there will be some metal chips in the oil. What have I done, and what is going on? Any experiences? :(

Pat Conlon

Does the crunching sound happen in all gears or just second?
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

motorider17


motorider17

I have tried accelerating hard up to 6k rpm in 1st. Makes the crunching sound but pulls normally

balky1

Sounds like something with the gears. Maybe it is time to open her up and fix everything in the gears that needs fixing along with necessary improvements. Maybe better to do that than to risk something failing inside while riding (in the middle of nowhere).


FJ 1100, 1985, sold
FJR 1300, 2009

motorider17

Quote from: balky1 on June 12, 2017, 02:16:11 PM
Sounds like something with the gears. Maybe it is time to open her up and fix everything in the gears that needs fixing along with necessary improvements. Maybe better to do that than to risk something failing inside while riding (in the middle of nowhere).

I'm afraid so. How many hours would you reckon a job like that is? For me, I will take the motor out and have the trans fixed by a workshop. Guess it's not possible to do with engine in bike?

FJmonkey

Not sure if your problem is related but the shift forks on the '84 to '87 years are a known weakness. Yamaha made them stronger on the '89+ and I think the XJR shift forks are even stronger. The most common symptom of bent shift forks is it popping out of gear under hard load. Not what you are describing, but if you split the cases then change the shift forks and have gear dogs undercut. RPM can get you sorted out, click on the banner above to see their web site.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Pat Conlon

This is a perfect question for Randy @ RPM. I'm sure he has seen a few race car engines over rev'ed.

Before assuming the worst (which it probably could be) could the automatic adjuster on cam timing chain be damaged?

Sit tight, let Randy respond.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

racerrad8

Is the chain too tight and causing the output bearing to make the noise?

Might a good time to mount the video camera so we can get some audio of the noise.

Randy - RPM
Randy - RPM

ribbert

The symptoms you describe are exactly those of a failed sprocket carrier bearing.

IMO

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

motorider17

Quote from: racerrad8 on June 12, 2017, 04:21:16 PM
Is the chain too tight and causing the output bearing to make the noise?

Might a good time to mount the video camera so we can get some audio of the noise.

Randy - RPM
Chain is not too tight, a little bit on the loose side. When I put the chain on I tightened the front sprocket nut really hard, to match the nut lock washer perfectly. Could this be it?
Yes i'll try to tape my phone to the swing arm to record the noise.

When I got time I want to take the front sprocket cover off to see if I can spot anything wrong. When I turn the rear wheel by hand I do think that the clicking noise made has become louder. The output bearing.. Is it a big job to replace?

racerrad8

Quote from: motorider17 on June 12, 2017, 05:59:25 PM
... The output bearing.. Is it a big job to replace?

Yes, the bearing has to be pressed onto the transmission shaft, so the cases must be split.

Randy - RPM
Randy - RPM

motorider17

My worst fear.. Guess i'll have to let it go cheaply then. I am more and more convinced that it's the main output shaft bearing. Maybe a hopeless question - I know the consequences, but how long can the bike usually be ridden with these kind of noises? I mean, it's not really that loud for now. But if I sell it on, should it be possible to ride the bike a couple of hundred miles or should it be transported by trailer?

ribbert

Quote from: motorider17 on June 12, 2017, 08:06:46 PM

.....I am more and more convinced that it's the main output shaft bearing.


Based on what?

You asked for advice, got it and now appear to be ignoring it. You could (should) replace all three bearings (do the wheel bearings while you're at it) for less than $50 and an hours work or take the wheel to a workshop if not sure how to remove and refit the bearings. They shouldn't charge anymore than 1 hours labour if you supply the bearings.
The bearings are common sizes and available from any bearing service. Use sealed bearings, not open ones like the originals. They are better and you can then re use your old seals if you have been careful removing them.

It's a small investment for what appears, from your description, to have a very high chance of being the culprit.
If not, you haven't spent much.
The sprocket carrier bearing (rear sprocket) is not to be confused with the output shaft bearing (front sprocket)

I've seen a lot of the former fail and rarely the latter and the symptoms are exactly as you describe.

IMO

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

simi_ed

Quote from: ribbert on June 12, 2017, 09:03:51 PM
Quote from: motorider17 on June 12, 2017, 08:06:46 PM

.....I am more and more convinced that it's the main output shaft bearing.


Based on what?

You asked for advice, got it and now appear to be ignoring it. You could (should) replace all three bearings (do the wheel bearings while you're at it) for less than $50 and an hours work or take the wheel to a workshop if not sure how to remove and refit the bearings. They shouldn't charge anymore than 1 hours labour if you supply the bearings.
The bearings are common sizes and available from any bearing service. Use sealed bearings, not open ones like the originals. They are better and you can then re use your old seals if you have been careful removing them.

It's a small investment for what appears, from your description, to have a very high chance of being the culprit.
If not, you haven't spent much.
The sprocket carrier bearing (rear sprocket) is not to be confused with the output shaft bearing (front sprocket)

I've seen a lot of the former fail and rarely the latter and the symptoms are exactly as you describe.

IMO

Noel

Noel is offering sound advice.  You might seriously consider following it.
I think I spent $30-40 on rear wheel bearing the last time (18 months ago) and 1-2 easy hours and it's done.  Your alternative is to pull your motor and start HOSING money in hopes that you might fix the problem.  Gaskets, undercut trans, shift forks, not to mention a lot of labor.  And this IS A BIG Project, at least it was for me and my garage.  Otherwise, you're looking at 10-20 paid hours for someone else to do this, plus all the above listed costs. 

Now, if you do have a bad output bearing, don't cut corners.  Change the trans, and all the forks.  It is possible to do this at home, but not a small task. Don't take it lightly, don't do it unless you have to. But if you have to, do it right!

Hmmmm ...  $40 vs $1,200-$2,000???
-- RKBA Regards,

Ed
===
Ed Thiele 
Simi Valley, CA -- I no longer have SoCal manners.
'89 FJ12C (Theft deterrent Silver/White)


- All that is necessary for the forces of evil to win in the world is for
enough good men to do nothing.

- Edmund Burke