91 force 150-scratched and loose piston

[z28se]

i got my 91 150 force running, it was given to me by my uncle. i took it to the lake and it made a real loud tapping noise so that afternoon i tore the engine apart and found out that #1 piston was very lose inside the cylinder witch was causing the tapping noise. The piston is very scratched but the sleeve and rings are fine. So im wondering if the pistons from my blown 87 125 will interchange

is it ok to use used pistons?
and is there anything else i should check on wile the engine is apart?

Also my uncle told me it was majorly overheated when he used it so i think thats what caused it.

 

[kandil]

Re: 91 force 150-scratched and loose piston

If the piston is lose you have some worn bearing you should get new ones and as far as using used piston it is up to you you should try to find out why it over heated or you will have the same problem again the right way would be to oversize it and reboar it you can find a piston kit on ebay for under $100 good luck

 

[Frank Acampora]

Re: 91 force 150-scratched and loose piston

Short answer--NO. the '91 150 is 3.375 bore and all 125 hp are 3.3125 bore.

It is perfectly acceptable to utilize used pistons in good condition if they are the correct size AND if there is no damage to the cylinder, but you don't have that choice with your 125 and 150.

You can buy WISECO pistons relatively cheap at outboard parts.com and I think i boats also sells them. Around 100 bucks for piston, wrist pin, rings, and small end rod bearing kit.

Of course, before you buy one, don't take my word. Measure the cylinder diameter yourself. 3.375 is 3 3/8 inch and 3.3125 is 3 5/16 inch

Since you were told that the engine was overheated, remove the lower unit and replace the water pump impeller. Check the thermostst to be certain that it opens when warm, and while the head is off, check the water passages to be certain they are not partially clogged.