Need help on piston failure

[Cortes165]

Re: Need help on piston failure

Walleyhed......you say<br />

Here's the kicker to me...Right on the P/N label on the piston box AND the instructions for that piston, it says: For bore size 3.530-3.531.

is this from an OMC piston???<br /> I would like to see that label. <br /><br />In regards to the machine shop (they don't know better). From what I have learned, he bored the cylinders to the dimensions the boat shop told him. He will resize to whatever I want.<br /><br />It's the mechanic that says it doesn't matter if the bore is a few thou under.

 

[walleyehed]

Re: Need help on piston failure

To be blunt... the Mech. is stupid.<br />The dimensions I was refering to are Wiseco labels, but remember, a 30 over piston means the BORE is to be 30 over std. regardless of piston manufacturer in this case.

 

[reeldutch]

Re: Need help on piston failure

sounds like the machinist is not familiar with outboards or just doesnt care.<br />next time things go wrong he will blame you because you told him to do this and that.<br />a good machineshop will bore and provide the pistons.<br />they will measure what the overbore they have to shoot for .020 or .030 etc and then they will rebore the cylinders to the pistons manufacturers specs.<br />they will take the sharp edges of the ports and will clean the block from metal shavings.and hone the cylinders.<br />than they will give you advise of the break in procedure.<br />this job on all 4 cylinders should not be more then 200 dollars.<br /><br />find a good machine shop and you dont have to worrie about that anymore<br /><br />reeldutch