[PastorErik]

A friend of mine has a 75 Yamaha GPX 433 the he recently rebuilt the top end and carbs...after about 3 hrs of riding it burned a hole in the left piston...some say it is a crankcase leak, another (very knowledgable man) says definitely the carbs weren't balanced.....any experience with this? any thoughts?
Thanks

 

[RtkatZL8]

Sounds like detonation damage, could be caused by too lean of a condition, wrong jets, timing too advanced or bad gas (too low of octane).

RtkatZL8
2001 ZL800
Delta IIs
Power Breather

Creek beds don't make good brakes!


MBRP Silencer

Edited by - rtkatzl8 on 13 Jan 2002 15:17:31

 

[Sled_Dog]

prolly running too lean. I don't quite get the unbalanced carbs. I mean they could have been on different jettings and the one that burned up was way too lean.