Help diagnose these pistons please

MountainMax

MountainMax

New member
Joined
May 19, 2003
Messages
747
Age
22
Location
Churchill Falls,NL, Canada
Finally I managed to lose a piston in my beloved 02 MMax BB, here are some pics, one had a chunk removed from it, other two look different on top, what do you think, was she lean? one piston looks a bit black and the bottom ring has stuck on, with no signs of piston damage at all, no scuffing or marks, what hapened here???
 

Attachments

  • 800Pistons (2) (600 x 800).jpg
    800Pistons (2) (600 x 800).jpg
    43.4 KB · Views: 12
  • 800Pistons (3) (800 x 800).jpg
    800Pistons (3) (800 x 800).jpg
    154 KB · Views: 7
  • 800Pistons (4) (800 x 800).jpg
    800Pistons (4) (800 x 800).jpg
    62.2 KB · Views: 8
  • 800Pistons (800 x 600).jpg
    800Pistons (800 x 600).jpg
    48.3 KB · Views: 12
Last edited:

How many miles are on that sled?? that black is blow by from wore out
rings,that should have been serviced long ago..
 
appears to have broken a ring. not a lean burndown. Is the 3rd picture the mag side? That would explain why they are different color from PTO to center to mag (black=rich)
 
BBlueSRX said:
appears to have broken a ring. not a lean burndown. Is the 3rd picture the mag side? That would explain why they are different color from PTO to center to mag (black=rich)
Click to expand...
I agree, can't really tell if there is ant melting..
 
Nothing apears to be melted or scored, just the top part broken and there is only like 1000km on this top end, it's a bender 800 top end kit, only second season using it. Now, where can i get new bender 800 pistons? i heard Bender went under.

HOWEVER......... Last season I did use Nitrous on this setup,since sold the NOS but maybe it done some damage that i never new about until this year when this hapened..........
 
looks like detination to me. had a few pistons on the mod sleds at work look like that. what are u running for gas? u should be running a high octane. also the bost could have cause it to start to burn threw.
 
I am assuming you limped it home? that would explain no wash on the broken piston. It is such a clean break I doubt it was detonation. I called Bender a couple weeks ago I will get you the number. I had to get it from my dealer. They are some serious pricks though. They could care less about customer service. I called their number out of the catalog and I got a ladies house number in Buffalo and she told me that bill collectors are constantly calling her about past due accounts from Bender. They packed up and moved apparently.
 
BBlueSRX said:
I called Bender a couple weeks ago/They are some serious pricks though. They could care less about customer service. I called their number out of the catalog and I got a ladies house number in Buffalo and she told me that bill collectors are constantly calling her about past due accounts from Bender. They packed up and moved apparently.
Click to expand...
Wow!!!!
 
did you lose the locating pin on the broken piston? the broken part could be the ring rotating and catching the port. Daman was right on about the black sides being blow by which indicates worn rings or out of spec piston (from heat cycles). the wash looks okay, close but okay. I'd say it's a wear issue and not a lean/burndown issue.
 
Bender 716-941-5840. Hopefully they have some parts for you. They told me to get #$%&* on parts I needed. "No longer stock them and we can't get them". Thanks for not backing up your product...
 
Last edited:
im gonna clean my carbs but it don't look like melted pistons which usually comes from a lean condition, I run only 91 octane supreme gas like Bender recommends, however i may have used one tank of 87 by mistake.....I did limp her home.

I looked at the pins and yup, 2 pistons top pins broke off and the rings moved, there is a slight mark on the top and bottom of the exhaust port but i think it will be fine, guess it just failed............

I called bender (now owned by dynoport) and ordered three new pistons. The benderracing website has current email and phone number or you can link it from dynoports web site, they did move after taking it over, they are back in the original Tim Bender shop where it all started, they seemed nice enough to me, two guys there use to work for bender before and he was very nice and friendly and accommodating for me.

Anyhow, thanks for all the replies guys, apreciate it.......
 
You must log in or register to reply here.


Back
Top