Surfriding OEM Crank pin sheared why ? pic included

Freakrider

Freakrider

X247
Location
Tampa Bay area
This oem crank has only 1.5 seasons on it...there was no water intrusion and I was at pretty low rpm when it broke...take a look at the color of the metal in the crank pin, instead of shiny metal it has a rust color to it ? The motor was always fogged after each day of riding...any guesses why it sheared ?

Fortunately no other engine damage...searching for a new oem crank or one with Japanese bearings...options ?DSCF1174.jpg
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
If it's a stock un-welded crank it is possible it may have been out of true from the pin slipping causing excessive stress on the lower rod pin.

Also that rust on the lower rod bearing isn't helping matters.

I'd go with an SBT crank and use that one for a core; at least they have welded pins.
 
Pablo

Pablo

sqeez bth levrs & lean bk
Site Supporter
Location
georgia
That new crank company Paul Lehr is using utilizes jap bearings. He said the cranks are oem specs and cost half the price.
 
2010brandingo

2010brandingo

TEACH ME HOW TO DOUGIE!
Location
ATL
i had one break like that years ago and crazy enough it still held together and ran, like crap, but enough to get back to the beach. the rod was the only thing holding it together. lol i would give the ones Paul has a shot... if he stands behind them thats good enough for me.
 
kevbo

kevbo

Location
dfw
There was a stress riser (dent, scratch, or forging debris) that slowly grew from fatigue. My lab looks at this stuff with an electron microscope. You were just the unlucky recipient of a bad part. Still a win for Yamaha since it made it through warranty and they get to sell another crank.
 
MADMAT

MADMAT

Location
Ohio
Wow that is pretty nasty for a low hour stocker!

1 in a millon.

(so.... your saying I've got a chance!!)

 
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Aircraftsalz

Aircraftsalz

Thrust built Dasa Power
Location
Off site
SBT for stock stroke cranks... Lucas, chris, blue and a lot of others have been beating on these cheap sbt cranks , haven't had one fail yet... Plus 1 yr fault free warranty

$200 how can you go wrong
 
Sanoman

Sanoman

AbouttoKrash
Location
NE Tenn
Try Havasu Watercraft Parts.He had several brand new oem cranks a while back that he got from new skis that had been in a fire*.And he is honest and a good guy.

*not a bad fire either.
 
Freakrider

Freakrider

X247
Location
Tampa Bay area
pabloescobar said:
That new crank company Paul Lehr is using utilizes jap bearings. He said the cranks are oem specs and cost half the price.
Click to expand...

yeah good way to go for longevity...http://www.x-h2o.com/threads/94678-ADR-Cranks

Paul Lehr said the lower crank pin is a cast and then machined part, it is magnafluxed for quality control and there can be imperfections missed. It prolly fractured and then very hot 2 stroke oil weeped down into the fracture to color it like that before it broke...that color is not rust but hot oil stain...he has only seen a few oem break this way in all his years...I guess it is one in a million...Paul knows his stuff !

Where can I order Riken rings in Florida beside the dealer ?
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Jump On It said:
yeah good way to go for longevity...http://www.x-h2o.com/threads/94678-ADR-Cranks

Paul Lehr said the lower crank pin is a cast and then machined part, it is magnafluxed for quality control and there can be imperfections missed. It prolly fractured and then very hot 2 stroke oil weeped down into the fracture to color it like that before it broke...that color is not rust but hot oil stain...he has only seen a few oem break this way in all his years...I guess it is one in a million...Paul knows his stuff !

Where can I order Riken rings in Florida beside the dealer ?
Click to expand...

WSM and PRO X both use those rings in their piston kits, any WSM , Western Power Sports or Parts unlimited dealer should be able to get you set , that includes me.
 
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