Left Side Crankcase Knock

[Turtleface]

Well, here's the story. Two weekends ago, took the bike over to a friend's house for a night of revelry. Parked the bike when I arrived, and wasn't on it again until the next day, after waking up. Road it home, had a great ride. Nothing odd happened, that I can recollect. No noises, weird vibes, nothing. Parked it in the driveway. Fast-forward twelve hours or so, I'm about to jump on for a quick sprint to the bank and back to deposit some cash. Fired the bike up, and was greeted with a sound I've grown to dread, in my automotive experience. The good old sound of a rod knock. Sweet jesus, it's not a nice sound.

I've pulled the plugs (they look perfect, replaced less than 100 miles ago) and turned the engine over by hand, and can't feel anything out of order, or hear anything odd. I checked the crank, via the spark plug hole + graduated stick method, and it appears to be straight. Pulled the valve cover, valves were about as tight as I expected them to be, clearances were on the low side, but still within spec. Opened them back up to the higher end, no change in knocking sound. Left side engine cover is now off, old stator was affixed inside the cover perfectly, no loose bolts, so signs of any metal to metal contact. Engine oil is still very clean, no signs of metal. I've taken this opportunity to install the Electrosport stator I've had laying around, and fuss with the electrical system a bit.

Any ideas on the knock? How do I go about checking the starter clutch? This is my best guess, as I don't think an actual rod knock would develop so quickly, or without any sort of warning. I've never had any problems with the transmission clutch, and don't expect it to be the culprit with 16k miles. I can't feel the knock through the foot pegs with normal street shoes on, and I can only feel it slightly with my bare hand on the engine case, or on the stator cover. I'm going to go back to spinning wrenches, and I'll let you guys know how it turns out.

 

[Theo]

EDIT: oh wait. I'm a dummy. You said it happens at idle so disregard.

This is just something I'm throwing out there but on another forum I read, someone thought they had a similar issue and it turned out to be the chain had to much slack and was hitting the frame. Again just throwing it out there before you do anything drastic.

 

[Turtleface]

This is just something I'm throwing out there but on another forum I read, someone thought they had a similar issue and it turned out to be the chain had to much slack and was hitting the frame. Again just throwing it out there before you do anything drastic.

Oh man, I'm going to feel really stupid, and really relieved if it's something like that. Can't be the chain though, I have had the bike in neutral for the past two weeks, and I've been super-anal about checking my chain since I've done my 530 conversion.

 

[chuck hahn]

what about the front sprocket nut being loose and slapping around a bit??????? or maybe even the starter itself being loose in the sump and knocking a bit???

 

[Turtleface]

what about the front sprocket nut being loose and slapping around a bit???????

Good there too. Anytime I have a problem, I check all the parts in my signature line first, to make sure I didn't ham-fist anything during a previous procedure. Front sprocket won't turn until I drop the bike into gear, anyhow. Starter appears solid.

 

[chuck hahn]

just envisioning what in tht area could rattle..glad to hear its not those...

 

[Theo]

Oh man, I'm going to feel really stupid, and really relieved if it's something like that. Can't be the chain though, I have had the bike in neutral for the past two weeks, and I've been super-anal about checking my chain since I've done my 530 conversion.

Yeah that's what I realized and why I put I'm a dummy in my edit.

 

[blowerbike]

rods don't knock on roller bearing cranks..
more than likely the starter clutch.
if i'd known..
i'd brought my puller.
i'm just down the road in N. phoenix for a week or so.

 

[Turtleface]

rods don't knock on roller bearing cranks..
more than likely the starter clutch.
if i'd known..
i'd brought my puller.
i'm just down the road in N. phoenix for a week or so.

New tools to buy! Where should I look to purchase the proper puller? I'm not terribly keen on damaging anything, if I can help it. Everything with teeth on it looks pretty good, starter gear teeth are fine, as are the driven gear's teeth. Nice and square, look brand new. What's the best way to take off the 22mm nut on the end? I tried blocking the rear wheel with a 1x2, but I snapped it in half. I then used both pieces of the 1x2 to block the rear wheel, and I can't get the nut loose. It's not reverse threaded, is it? I have a 3/8" and 1/2" impact wrenches, of the air driven sort, and a 3/8" impact driver. Should I get the compressor fired up?

 

[rapidray]

Before you go spending money, pull the clutch cover, pressure plate, & see if the clutch hub nut or the clutch hub are loose. Ray.

 

[Turtleface]

Before you go spending money, pull the clutch cover, pressure plate, & see if the clutch hub nut or the clutch hub are loose. Ray.

Good call. Looks like I know what I'm doing tomorrow morning.

 

[Turtleface]

Got bored and pulled the clutch cover. Nut was nice and tight. Hub was tight as well. Pulled out all the clutch discs to inspect, all seems well. Pulled exhaust and dropped the oil pan, everything looks well there. Nothing strange waiting in the sump, residual oil left in the pan is clean. Hmm, maybe now would be a good time to send off my engine covers for painting...

 

[Guest]

I second the starter clutch now that you eliminated the clutch.

 

[Spyderman]

did you check for loose springs in the back of the clutch hub while it was apart?? just a thought before you go after the starter clutch

 

[Turtleface]

I second the starter clutch now that you eliminated the clutch.

I hadn't had any sort of problems with the clutch, ever, but it was worth it to see how it all works, and you never know until you check, right? Now, I've got a few questions!

What's the best way to get the starter clutch nut off? Is it worth it to invest in an APE heat treated steel nut? APE clutch hub nut? How about a good supplier for a puller? Might as well refresh the clutch while I've got it all apart, I need the nine of the fiber discs, and new springs, right? Steel discs can be cleaned up and re-used? I'll get pictures of all the clutch hub and the starter bits up tomorrow sometime.

 

[Turtleface]

did you check for loose springs in the back of the clutch hub while it was apart?? just a thought before you go after the starter clutch

You mean the piece numbered 1? How do I go about checking those springs? It doesn't seem like it'll come out of the engine through the clutch cover opening, but I didn't really mess around with it terribly much. I pulled out everything up to the inner basket piece, #5.

 

[Turtleface]

You mean the piece numbered 1? How do I go about checking those springs? It doesn't seem like it'll come out of the engine through the clutch cover opening, but I didn't really mess around with it terribly much. I pulled out everything up to the inner basket piece, #5.

Figured out how to remove the hub. Four of the six springs in the clutch hub are quite loose. Two of them aren't as loose, but still loose. Two of them are painted yellow, if that helps identify them. Interior of clutch area has sediment in the bottom of it. Grey in color, very very fine particles. No large pieces of anything looking like metal. Perhaps it's clutch material?

 

[rapidray]

Yes on the clutch material & yes on the APE hub nut. I am guessing you may want to send the clutch hub out & have it rebuilt into a heavy duty one since 66% of the springs are loose. If I can help you out give me a call at 714-356-7845. I am up for another half hour or so & will answer questions to help. Ray.

 

[mushman]

I've got the same (similar) problem only mine started knocking when I'm underway. I checked for and tightened a loose chain and that did remedy it initially, but then the noise returned. Countershaft sprocket is fine, clutch basket looks fine and doesn't feel loose. I had to button it back up before I could completely pull it because I had to move my entire household and shop. Major pain. I guess now I'm gonna pull the motor and eventually split the cases to have a look inside the tranny. Hopefully in the process I'll find it before I have the top end off, (clutch removal and alternator covers first). Maybe it'll be the starter clutch but as I said, I only get the knocking noise when I'm accelerating so I'm not holding my breath on that diagnosis.

 

[Turtleface]

Yes on the clutch material & yes on the APE hub nut. I am guessing you may want to send the clutch hub out & have it rebuilt into a heavy duty one since 66% of the springs are loose. If I can help you out give me a call at 714-356-7845. I am up for another half hour or so & will answer questions to help. Ray.

Indeed, I'm definitely sending it off to have it rebuilt. Think it'd be worthwhile to go with a billet basket? I'm planning on building a larger (1300cc-ish) motor in the distant future, and I'd like to make things as strong as reasonably possible, and am willing to spend the cash. Falicon? APE? Who's got the strongest rebuild?