Twisted crank? '82 GS1100E

[rphillips]

Hey Ray, please correct me if I'm wrong, but I think the journal you can see from behind the clutch hub, wasn't welded ,from the factory, even on the later models. The aftermarket weld jobs weld all of them.

[mike_of_bbg]

Yeah, the crank on my 82 gs550 was twisted. Compression test was very low on 1 & 2 (~60 psi vs 120 psi on 3 and 4). I'd estimate the twist at about 20 degrees. Never ran the bike in that condition. The PO apparently didn't notice at all, but he probably got the bike like that.

http://www.thegsresources.com/_forum/showthread.php?t=138429

+1 take measurements directly between TDC and PDC. I couldn't tell visually when we first got the head off with 1 and 4 at TDC. After turning the motor I was able to visually notice that 2 and 3 were not traveling together.

[trippivot]

take out the #1 and the #4 spark plugs.
remove the timing cover
put a plastic straw or a skinny tool into the plug hole to locate the top of the pistons.
turn engine over to TDC 1-4

if the piston crown level of both 1-4 pistons are uneven at TDC you have a twisted crank.

simple test

[mike_of_bbg]

if the piston crown level of both 1-4 pistons are uneven at TDC you have a twisted crank.

If they're uneven anywhere along their travel you have a twisted crank. Depending on how far it's twisted TDC/BDC may be the hardest places to tell. I'd measure in a couple of places if you suspect a twisted crank. Make sure that you also check between TDC and BDC. Like I said mine was twisted about 20 degrees. That's only a 7% difference in vertical travel at TDC. It's about a 34% difference (relative to crank offset) at 90 degrees.

[maro]

Just for the sake of including this in this thread. Let's say I twist my crank . What is the cost and process of replacement?

[rapidray]

Just for the sake of including this in this thread. Let's say I twist my crank . What is the cost and process of replacement?

MINIMAL, the cost of a GOOD used, or new crank, & all the gaskets. Depending on mileage on the motor I would do other things. Pull the motor, pull the entire top end, split the cases, replace parts & re-assemble. Ray.

[TheCafeKid]

Just for the sake of including this in this thread. Let's say I twist my crank . What is the cost and process of replacement?

Back when Dave and Isleoman did it, it probably fell under warranty...for you and I?? It would be cheaper to find a new motor, or buy another bike. You're looking at COMPLETE disassembly, sending the crank off to get straightened, welded, indexed, etc, New crank bearings all around...As Blowerbike said, and caused me to laugh as well as cringe, it would simply "blow your wallet apart" HA! In other words...DONT TWIST IT

[mike_of_bbg]

I was looking at a top-end teardown (and thus a full gasket set) anyway due to a leaky head gasket, and found a good used crank on eBay for about $50 shipped. So the "extra" costs were the used crank, seals, and threebond. Not that bad (~$100), but there's definitely some risk to buying the used crank. I probably should have replaced the timing chain too, but it measured well within spec so I kept it.

Of course there's also the time involved in removing the whole motor and tearing down the bottom end.

[TheCafeKid]

Hey Josh, If you're really that worried about it, when ya have the spare cash, id start shopping and eyeballing EBay and CL for an 83 motor or parts bike (yeah, its not going to be a dime a dozen, but they ARE out there) Keep in mind that the 83 motor IS welded, but its only welded at the pins, so its still possible to twist one (i dont think under NORMAL circumstances however. If you're riding like an idiot, maybe, or if you've got too much power over it...Maybe..) Then you could simply swap all your stuff over to it, and not really have to worry about it anymore..Plus.... The BLACK motor is FASTER

[woodman]

"The Cafe Kid", at the risk of me being called a dumas, please elaborate on how the rotor threads will tell you if the crank is twisted. The threads on my 80 that spun the rotor were perfect, just the nut had come loose. I dont suspect anything is wrong, Im just curious about it

[TheCafeKid]

"The Cafe Kid", at the risk of me being called a dumas, please elaborate on how the rotor threads will tell you if the crank is twisted. The threads on my 80 that spun the rotor were perfect, just the nut had come loose. I dont suspect anything is wrong, Im just curious about it

Did i say that?? I dont recall saying such a silly thing?? I think i said that you can tell by looking at the rotor threads whether or not you have the big end welded crank....ANd I might ADD, thats im MOST cases, it wouldnt suprise me if the THIRD rotor type wasnt used on the 82 motors as well, but its at lEAST a good clue..

[woodman]

"the rotor threads will tell you... " Thats your whole post, your words, maybe I misinterpered them

[TheCafeKid]

Not exactly...BUT, supposedly anything AFTER June of 82, and with the motor number higher than 14K have a VERY HIGH chance of having the big end welded crank in them.. Bert, you can tell simply by pulling the Stator cover...

No and its a very different kind of high frequency vibration, I have a Fatboy too. How do you tell by taking the stator cover off, all I see is the crank end and a seal ?

the rotor threads will tell you...

That make it more complete??

[gearhead13]

You poor guys with your pressed together cranks
Mine is forged steel, double cross drilled, aint gonna twist that sucker.

[bonanzadave]

Back when Dave and Isleoman did it, it probably fell under warranty..

Yes it did. That crank, a set of front brake rotors, and a stator. That Zuk dealer hated to see me.