82 450T - Possible bad crankshaft

[bwanna]

Hi,
Something doesn't seem right. The right side has some additional noise that I can't pinpoint. It appears to be from the lower part of the engine around wear the crankshaft is located. I took off the timing cover and noticed the crank seems to be rotating in an offset-like manner. Please check out the video.



My question is: Does it appear that the crank is slightly wobbly? If so, what are some of the possible causes? Possible fixes?

 

[tom203]

Me no see video! anything loose on signal generator, advance ? noise at just idle ? this is a plain bearing crankshaft; did you run it without oil?

 

[bwanna]

Me no see video! anything loose on signal generator, advance ? noise at just idle ? this is a plain bearing crankshaft; did you run it without oil?

When I click on the picture the video comes up. Not sure why it's not working for ya.

Nothing loose on signal generator. Noise appears to be at all speeds, increasing with frequency as engine is rev'd. I believe it's a plain bearing crankshaft. Never run without oil. I change it frequently as I commute daily 55miles.

 

[tom203]

OK, I see link -but it doesn't like my browser, so I did not view. I'll let someone else comment. You're not talking about little tab on advance mechanism wobbling,are you?

 

[bwanna]

OK, I see link -but it doesn't like my browser, so I did not view. I'll let someone else comment. You're not talking about little tab on advance mechanism wobbling,are you?

No. My concern is the wobble of the entire crankchaft. It appears the end of the crank is off round. Your browser may only need to update a driver or something. If you can see the video you'd see the end of the crank not turning perfect centered, but slightly turning offround. It's very prevalent at idle.

 

[Guest]

Woa?

Yes they do wobble a bit, Not that much !

With the engine off can you lift the crank and move it up and down at all on that side ?

The video will play tricks on you because of the refresh rate of the camera but you see it smooth out with more speed.

However that does seem excessive.

Yes it is definitly a plain bearing engine.
There are 12 bearings halves for it and the balance shaft.

I'd say you have some worn bearings...

I've seen the cranks move a bit but not that much.

It could have been that with speed and oil pressure you were not noticing anything wearing but over time the oil pressure wasn't enough and the bearings may have made contact and now its worn too far.

Dissassemble your last oil filder or the one you just put in and look for aluminum dust.

Have you ever installed an oil filter backwards? ( long story )


You Could take the right side cover off and see if you can move the crank at all.

Normally there is just some ion and out play but never up and down, at least you would need a dial indicator to see the difference in the movement.
The gear that drives the counterbalance shaft is also on that side. That will put extra stress on these bearings when they start to fail and lead to a slapping motion which wears them out quicker and makes noises!.

check this out.
This is a video of what happens when you either use gasket sealant on the right side cover and it clogs the oil port going to the counterbalance bearing or if it just fail's from use or debris.

https://www.youtube.com/watch?v=Atq4nKfh7kg

After removing that bolt you would see a sleeve and no bearings left.
That sloppy gear meshing would later would cause the crank to move just enough to start making contact with the bearing surfaces until there was nothing left and it was floating on oil.

 

[Guest]

The only wobble you can see from there is the advance/crank trigger.
If it was dropped on that side with the cover off or wrecked with the cover on it will wobble.
The bearings and cases would not let the crank wobble and if it did it would not turn.

 

[bwanna]

The only wobble you can see from there is the advance/crank trigger.
If it was dropped on that side with the cover off or wrecked with the cover on it will wobble.
The bearings and cases would not let the crank wobble and if it did it would not turn.

Last year an idiot pulled in front of me from a stop sign and I had to lay it down...was able to power slide it so my rear tire connected with his front tire. That was about 10k ago.

The damage was limited to superficial. The bike had a crash bar at the time of the crash.

Recently, the oil pressure light is coming on now at idle after its been warmed up.

So, do I need to crack the engine?

 

[bwanna]

The only wobble you can see from there is the advance/crank trigger.
If it was dropped on that side with the cover off or wrecked with the cover on it will wobble.
The bearings and cases would not let the crank wobble and if it did it would not turn.

Are you suggesting that the wobble could be beyond the bearing outward? I do feel a very slight thumping and here a matching pattern in sync with the rpms. This appears to be on the right side. It's still very slight, but has very gradually increased over time.

Are there other symptoms I should look for?

 

[Guest]

Low oil pressure is a sign.

Start with removing the right cover and see what you find.

 

[bwanna]

Low oil pressure is a sign.

Start with removing the right cover and see what you find.

I'm going to do that. Low pressure, sign of bad bearings?

 

[tkent02]

What scares me is that the wobble seems to come and go. Could be just a camera thing though, but does it look like that with your eyes?

Sometimes it looks straight, sometimes it's a little off center, other times it seems to wobble 6 - 8mm?

 

[bwanna]

What scares me is that the wobble seems to come and go. Could be just a camera thing though, but does it look like that with your eyes?

Sometimes it looks straight, sometimes it's a little off center, other times it seems to wobble 6 - 8mm?

I'm fairly sure the wobble I'd consistent. The engine also has a slight thumping that matches... gotta pull the side off.

 

[Guest]

I'm going to do that. Low pressure, sign of bad bearings?

Yeah, bad bearings, bad pump, loose pump, loose pressure regulator,
Blown out gasket behind the cover allowing all pressure to escape inside the cover.

 

[bwanna]

Well, I've pulled the right cover and did not observe any play whatsoever in the crankshaft. I did notice the ability to push and pull the crankshaft a little - creating a knock inside.

How much should the crankshaft move in and out (left and right while sitting on the bike)? I didn't measure it, but it looked to be at most a 1/20".

I also pulled the oil pump and examined all of that. The metal parts were within spec and I replaced the oil seals. This morning after riding for about 30 mins I came to a light and the oil light flashed on for a little bit. It didn't come on and stay on like before, but it did flash as the bike dropped to idle.

So? Any thoughts?