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@mjrally avatar
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73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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UTC quote
Anybody ever come across this? Obviously replacing this stock PX150 crank ASAP.
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parallelogramerist
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parallelogramerist
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UTC quote
Ugh, not that bad, but i used to have a TS1 240 kit that had a crank that rubbed on the webs. I dunno what caused my web rub, but i ended up throwing away the (expensive) crank and sold the cylinder kit.
@chandlerman avatar
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Lucky
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 79 P200E, 66 Lammy S3
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@chandlerman avatar
76 Sprint V, 63 GL, 62 VBB, 05 Stella, 66 Smallstate, 79 P200E, 66 Lammy S3
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UTC quote
That's ugly looking. Is it just on the one side?

I don't know what's causing it, but I'd guess bad casting of the conn rod if it's one side or too much clearance between the webs if it's both?
@qascooter avatar
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Ossessionato
79 P200E (Ruby), 62 Allstate (B-62)
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Ossessionato
@qascooter avatar
79 P200E (Ruby), 62 Allstate (B-62)
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UTC quote
Dang...Gnarly.....
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@mjrally avatar
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Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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UTC quote
chandlerman wrote:
That's ugly looking. Is it just on the one side?

I don't know what's causing it, but I'd guess bad casting of the conn rod if it's one side or too much clearance between the webs if it's both?
Just the one side. 6K mile stock crank from my 05 PX.

Brass shims on the big end bearing aren't that worn. Bearing doesn't feel bad with the heel of your hand feel test.

Wish I had a jig to check run out.
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parallelogramerist
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parallelogramerist
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That's very peculiar that it would happen on a "newer" PX150. Stock, hose engines are so darn weak that i wouldn't think that a simple seize could cause the con rod to get bent. I've never heard any bad reports before on the 2005 PX150 cranks...until now. Lemme ask, so is it still the original crank, or has it been replaced before in the past by someone else? Or maybe someone dropped the crank during a prior rebuild?...but i can't think of any reason that a 2005 PX150 would need to be rebuilt with less than 6k on the engine.
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@mjrally avatar
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Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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UTC quote
It's got the piaggio logo cast into the connecting rod. Don't know if that means anything other than stock. I opened it up to install the Malossi 24/63 overdrive kit on it and found the rubbing.

Anyone hear of bent cranks caused by using the electric start on a hydro locked motor? Ural (Russian sidecar bikes) have a bad reputation for wrecking cranks that way. Made me wonder if the same thing could happen here.
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parallelogramerist
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parallelogramerist
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MJRally wrote:
Anyone hear of bent cranks caused by using the electric start on a hydro locked motor? Ural (Russian sidecar bikes) have a bad reputation for wrecking cranks that way. Made me wonder if the same thing could happen here.
I don't think the PX's E starter has nearly enough torque to bend the rod in a hydrolock situation. I've hydrolocked my PX200's engine before (the cylinder filled up with fuel). I didn't realize it was hydrolocked and i tried kicking the engine over, but no way was the piston going to budge.
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Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
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Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
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UTC quote
Twisted crank would be my first guess. If straightened, it's still ok to run with that rod.....for as long as it lasts.
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Style Maven
'74 50s x3 '87 PK125XL '92 PK50XLS Plurimatic - & - '58 AllState '68 Sprint '66(?) Super125 and '72 DanMotor Super150
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UTC quote
So you didn't know until you saw it? No unusual noises? It almost looks like it was machined in there by the regular finish, and not rubbing by the same even color same as the rest. Have you looked inside the web, any metal to metal contact?

Maybe an insurance clearance cut when it was machined for rods that are a bit off sideways but otherwise useable? The distance from big end pin center to the edge of the web appears a little longer than to the edge of the odd area for what it's worth. Odd. :?
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OP
@mjrally avatar
UTC

Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
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Location: Oceanside, CA
 
Veni, Vidi, Posti
@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 59 Ser 2, 65 Silver Special, 90 V5N 50, 2015 HD Road Glide Special
Joined: UTC
Posts: 5142
Location: Oceanside, CA
UTC quote
No noises or anything unusual. Just something I found during the strip down. I ride this scoot once a month or so. Just around town and then park it till the next time. It has always been too slow (150 gearing) to take it any distance. I bet I've put less than 500 miles on it in total.

The web itself looks pristine. No marks, burrs, blueing, smooth spots etc. The rod was the sacrificial piece. Buying a replacement and tossing it unless someone wants it to dissect.
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