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? :(
Does the crunching sound happen in all gears or just second?
I believe it's in all gears, maybe a tad higher in 1st.
I have tried accelerating hard up to 6k rpm in 1st. Makes the crunching sound but pulls normally
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).
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?
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.
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.
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
The symptoms you describe are exactly those of a failed sprocket carrier bearing.
IMO
Noel
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?
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
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?
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
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???
Sorry it was not my intention to ignore your good advices based on your knowledge and experience. It's just that I assumed the worst based on the noises I got. I'll do a 25 mph 10 mile limp to the shop to have the bike checked. I was not able to get a clear recording of the noise as it was impossible to hear on the playback.
https://youtu.be/-YPchrwfAkw
Here's a vid. When I put my fingers on the front sprocket while turning the rear wheel I could feel the clicking. But there was no play on the axle.
I had a short testride and the noise was gone. But something didn't feel right when cornering. I have little experience fixing motorcycles, but is this noise normal?
Quote from: motorider17 on June 14, 2017, 02:35:02 AM
https://youtu.be/-YPchrwfAkw
Here's a vid. When I put my fingers on the front sprocket while turning the rear wheel I could feel the clicking. But there was no play on the axle.
I had a short testride and the noise was gone. But something didn't feel right when cornering. I have little experience fixing motorcycles, but is this noise normal?
A good mechanic could pick your problem in 10 ft, but if you don' t have access to one of those you are stuck with internet advice based on your description.
A noise that only happens while accelerating and with the weight of the bike on the road is unlikely to be replicated on the stand spinning the wheel. Your suggestion that it felt funny around the corner still points to a problem in the back wheel, be it the carrier bearing or wheel bearings.
Don't be fooled by bearings that feel smooth when turned by hand either. Unless literally falling apart, shot bearings feel smooth without load on them.
I couldn't hear anything unusual in the video, but that means little, I'm half deaf.
Keep us posted.
Noel
I have to warn you .About 25 years ago I had same symptoms on my 1100 i ignored it and one day my backwheel locked up in a lefthand corner and i crashed i was lucky as speed was low.Just seconds before that i was in high speed...
It was impossible to get the bike in gear after that.I had to come back and pick up the bike in a van. and the gearbox had to be rebuildt with a new second gear sprocket.
^^^Good advice. If the tranny locks up, pulling in the clutch lever won't help you..... :bomb:
Thanks for your advice. Friday I will have the bike checked by a mecanic. He have been fixing Yamahas for 30 years, so i'll post the results. I will leave the bike at the shop and get on the bus to get home. Hopefully it's a small job.
I'm glad to hear you're getting it looked at. Good luck!
The shop lubed the chain and had a test ride. Bike appears to be fine and they advised me to change oil and look if i can see any metal chips. So it looks like the biggest problem was inside my head.
Glad to hear another old FJ is still on the road. Hey, treat her with a little respect. I short shift thru 2nd and really don't push the engine in any gear. Damn, our bikes are 33+/- years old.... that's like 231 in dog years!
Until you change out the soft oem shift forks, sure go easy in second gear....but FJ's (well maintained, well tuned) absolutely love living in the kookaloo zone.
They are most happy when they are singing their 8k rpm song. They are amazing engines.
Quote from: Pat Conlon on June 20, 2017, 07:48:54 PM
Until you change out the soft oem shift forks, sure go easy hard/positive when Shifting in to second gear....but FJ's (well maintained, well tuned) absolutely love living in the kookaloo zone.
They are most happy when they are singing their 8k rpm song. They are amazing engines.
Minor edit...
Quote from: FJmonkey on June 20, 2017, 07:55:34 PM
Quote from: Pat Conlon on June 20, 2017, 07:48:54 PM
Until you change out the soft oem shift forks, sure go easy hard/positive when Shifting in to second gear....but FJ's (well maintained, well tuned) absolutely love living in the kookaloo zone.
They are most happy when they are singing their 8k rpm song. They are amazing engines.
Minor edit...
To ensure a "positive shift", you should upgrade to the
RPM Roller Shift Detent Kit (http://www.rpmracingca.com/proddetail.asp?prod=RPMRollerShiftkit). The kit uses a roller bearing detent lever and a stiffer spring for that quicker, more positive shift to make sure the transmission cogs get engaged properly.
The early shift forks were not "soft" so to speak, but they were much shorter than the current forks which allowed them to flex and disengage the cogs.
Randy -
RPM (http://www.rpmracingca.com)
Thanks for the tip, looks like this is what I need. Appx. How many hours is needed to fit these?
Quote from: racerrad8 on June 21, 2017, 10:44:59 AM
To ensure a "positive shift", you should upgrade to the RPM Roller Shift Detent Kit (http://www.rpmracingca.com/proddetail.asp?prod=RPMRollerShiftkit). The kit uses a roller bearing detent lever and a stiffer spring for that quicker, more positive shift to make sure the transmission cogs get engaged properly.
The early shift forks were not "soft" so to speak, but they were much shorter than the current forks which allowed them to flex and disengage the cogs.
Randy - RPM (http://www.rpmracingca.com)
Its worth each cent!. Miles better that the Factory shift kit. Soft, precise, positive, there is no risk of losing a gear when riding hard. One of the best improvements that I´ve done to my FJ