Engine knock

[laxman]

Got about 60k miles on the bike, a vague knock started developing. Wishful thinking it could be exhaust gaskets, sucked a little atf & confirmed the leak. After replacing the gaskets on the # 1 & 3 cyl, engine became quieter but the dreaded knock remained.

 

The knock initially seemed to be coming from either the #3 cyl or clutch basket area. Also noticed the idle became a little rough and a fine vibration can be felt on the right footpeg. Checked carb synch and they were. Pulling the clutch in didnt change the noise. Ultimately I shorted out the cylinders and confirmed the knock came from the #3 cylinder. Rod knock.

 

I'm wondering if it is possible to replace the bearing without the pulling the engine out of the bike? How much incidental parts are involved asidede from the gaskets and bearings? Or are we talking about a complete A-Z rebuild

 

Any input would be appreciated.

[Condor]

I'm wondering if it is possible to replace the bearing without the pulling the engine out of the bike? How much incidental parts are involved asidede from the gaskets and bearings? Or are we talking about a complete A-Z rebuild Any input would be appreciated.

 

My first '83 clattered and rattled like crazy when I first bought it, and after changing out the oil to motorcycle specific it quieted right down. It had 42K on it when I picked it up, and there's no telling what the PO used for oil. I used 20-50 valvoline. I'm not saying that's your problem, but just 'thinkin'. I've never had any reason to pull the bottom plate off the motor so wouldn't know if you could replace #3 bearing or not. I would think so.... I've done it on car engines..., but you never know what these design engineers are smokin' when drawing. The one possibility that may cause you to pull the motor is that it's a wrist pin and the piston will need to be removed??? Heck, I'd put a heavier grade of oil in it and see if that doesn't help.

[muffinman]

Laxman

describe the knock to us some of the bikes have a light knocking sound on the right side that is in the clutch basket area. My 83 has a slight knocking sound from the basket area and when I did the tranny I looked at the bearings and there was no problem with them either time I had the motor out the bike had 44k the first time I split the case and 118k the second.

Yes you have to pull the motor to split the case and get at the rods.

Your noise may be from an out of adjustment valve.

let us know

Jeff

[Squeeze]

.....

Yes you have to pull the motor to split the case and get at the rods.

...

 

Sorry, but i disagree

 

If it's the Bearing on the Crankshaft, then undo the Oilpan, the Oilrig and then open the Bolts on the Rod. If it's the upper Bearing, then undo also the Head and take the Piston out. Should be manageable, while the Engine in Place. OK, it might be a hassle this Way, but it is doable. Dismounting the Engine is also not just a 48 Minutes Job.

[laxman]

Thanks for the feedback guys.

 

The knock is not too audible. You have to listen carefully to distinguish it. What threw me off was the noise totally goes away when you short out the cylinder. Also a sort of "pounding" - like fine vibration can be felt on the right peg. I use Castrol active 10-40 oil, will try 20-50 and see if it helps as a last ditch effort.

 

If the engine has a real problem, I'm sure it will manifest itself in time and the noise will be more pronounced. I'd hate to tear this engine apart now only to discover normal wear.

[BradT]

Sorry, but i disagree

 

If it's the Bearing on the Crankshaft, then undo the Oilpan, the Oilrig and then open the Bolts on the Rod. If it's the upper Bearing, then undo also the Head and take the Piston out. Should be manageable, while the Engine in Place. OK, it might be a hassle this Way, but it is doable. Dismounting the Engine is also not just a 48 Minutes Job.

 

I honestly do not believe you can get the heads off the bike while the engine is in the bike. It will be a pain to get the lower caps off the Rods while the engine is in the bike. They are way up and on a big angle, you need a swivel to get at the bolts. It was a pain with the engine upside down on the ground.

 

I removed all the platic and pulled the motor, it took 3 hours on my 86. Once all the plastic is off it is not hard to remove the motor.

 

Brad

[Thom]

i had a lite knock on the on the rite side , i change to rotella dino and it went away .

[laxman]

Talking about a twist on the causes of my engine noise. Found 2 concerns I never expected :

1) #3 spark plug was loose

2) #3 cyl ignition pulses were inconsistent, in short it misfired.

 

The combination of the above contributed / amplified the noise which probably is the clutch basket. Anyway, any problem not involving a engine teardown is good enough for me. Even if it means a new TCI on problem #2.