what would cause pistons to crack?

[stinky93071]

So 5 weeks ago i took the bike to the shop, It was smoking (bad) and hard to start. before something "broke" i took it in..

long long long story short 3 new pistons rings and sleeves.. I have no clue what would cause this.. anyone have any ideas? oil change regulatory, no red lines.. not sure, no clue..

I should have it back next weeks but 5 weeks is a little nuts if you ask me..  

[stinky93071]

well i think i have hit the red line 3 or 4 times on the bike.. in the time i have owned. it..
Oil is am amsoil, changed ever 2-4k (depending on how or where i am).. and not run low.
only 45k as mileage goes..
and the dealer has done all service..

so i am not sure whats going on.. but all three are getting changed out.. ugh..

I had my cbr for 75k no problems my little GS500 for 40k no problems.. I am kinda bummed about this..

[black hills]

I would do a little research to see if this is a common problem, or even a recall item if you are not the original owner. I would guess a bad batch of pistons if you know the bike has not been mistreated.

[bomber]

if my eyes do not deceive, your avatar seems to show a late modle Triumph  . . . I know that some of the 1050 mills suffered from broken lands and other piston related issues . . . . .

the factory was doing a fair number of good will fixes . . . .

and it take a long time for parts to arrive form Merry Olde . . . one fo the prices to pay for Triumph ownership (and one of their biggest downfalls, IMO)

[stinky93071]

ya its an 06 sprint.. I have looked around but not found anything major.. ugh.. oh well.. should have the bike back next week.. only 6 weeks to fix..

[bomber]

likely nothing you did -- the problem went away in late 07 (build date), and didn't impact all scoots of that era . . .

just hang on to your paperwork, in case you got old-style pistons (I think they were supposed to have been purged from the pipeline)

[DNA]

I also had many a problem with mu 955 sprint.

at 56K I lost the #1 cyl.

I think bad gas that detonated and getting stuck in a highway jam in mid summer resulting in overheating contributed significantly.  My problems started after that.

[stinky93071]

honestly i just want my bike back.. ugh.. 5 weeks of real nice weather.. twitch twitch twitch..lol

[Papa Lazarou]

sell it and get another one

[mxvet57]

When the connecting rod snaps.  

[Andrew]

When the connecting rod snaps.  

That'll buff right out  

[stinky93071]

well i knew there was something up.. that's why it when in when it did.. i didn't want to have more damage if it was something big..

[X1Glider]

Considering most stock pistons are cast, a crack was probably waiting to propogate from the time it came off the line in the shop.  All it takes is for a machine "operator" to overtighten a part in a fixture to impart excess stresses when the machining process already causes enough of its own.  There could have been improper coll down after casting, something to do with breaking the part away from the sand,  thermal treatments and whatever else along the way.

[naustin]

and the dealer has done all service..

There's your problem....  You mean you paid them to do the service, and the "said" the did it, but really, they saved the shop costs on that expensive amsoil and took your bike for a joy ride ...

[stinky93071]

i do all the oil changes.. i get the oil for not much more than any other oil..

[oldenslow]

Do you have some pics of the damaged goods?  

[stinky93071]

nope still at the shop.. ugh..

[stinky93071]

just got the bike back yesterday.. replace all three pistons. only took two months.. ugh.. I did get 400 miles in yesterday..  

[DNA]

So - share the pain - what did that cost ya?
$2k?

[naustin]

If I were you - I'd trade that bike off ASAP.

[X1Glider]

If I were you - I'd trade that bike off ASAP.

Note to STN members... do not buy Stinky's bike... or naustin's.  

[naustin]

Oh, I'd disclose/advertise the rebuilt motor as a bonus feature.  I just wouldn't personally trust it....

[stinky93071]

So - share the pain - what did that cost ya?
$2k?

2.2k..

today is the first day i cracked open the throttle. I am not sure how long i have been "under powered" but the 2nd gear front wheel lift off  makes me think some time..  

as far as selling it.. not going to happen. The bike was a birthday present from my dad. He pasted just over a yr ago, I have to many memories of him and I on the road together (not as many as i would like but enough)

[Mr. Whippy]

Meh,

Done by a reputable bulilder (or conscentious home builder) and the motor is as good or better than when it was first built.    Heck, I just bought a Suzuki King Quad with a rebuilt motor from a guy I know who runs a construction company, but was a motorcycle racer/mechanic/owner back in the '70's.  He's torn down and rebuilt a bunch of motors of the years, many much more complicated than a motorcycle/ATV motor  (for example the diesel engine in a skidsteer or excavator).

[tomek]

Just ride that sumbitch till wheels fall off , not worth selling it now and you do like the bike .

G/F` 1997 yzf 1000r ( thunderace ) started to burn oil somewhere around 35 K mark ( like 3 qts per 1000 miles  LOL ) , it is well known issue with this particular model and year . Internet rumor says faulty pistons and / bores out of round cause that .
Anyway , the block was sent to APE for 1.5 mm overbore to match forged Wiseco pistons . About 700 bucks for pistons and machine shop services .
The bike now has 85 k miles and runs perfect .