Pics of my pistons & cylinders 1997 Speedster

[Chips]

I am tearing down my port engine to inspect and replace whatever I need to. Its had low compression since I bought it (125psi'ish) and I can feel play in my rotary shaft when holding the flywheel tight.

Anyway, how do my pistons look? Also, what exactly do I inspect to verify if my crank is needing any attention?

The cylinder walls look to have burn marks and some verticle lines but there arent any grooves you can actually feel.

Lastly, is it worth it to go with forged pistons in this setup or save the money and go with regular old cast pistons.

Sent from my GT-P7510 using Tapatalk 2

 

[Chips]

No love for my piston and cylinder pics? I'm just gonna throw in a new top end but would like to know what to inspect on the crank to make sure its within specs.

However, if you have any comments on my piston condition please let me know...they seem "ok" to me...

Thanks!

Sent from my GT-P7510 using Tapatalk 2

 

[Dr Honda]

Sorry I missed it. Give me a couple minutes, and I"ll be back.

 

[Dr Honda]

I'm seeing a lot of scratches in the sleeves, and the piston skirts are warn.

New rings will bring the compression back up... but then again... the pistons may just shatter. If it was mine... I would go oversized, and just to the top end right.

 

[Chips]

Thanks Dr. Honda, you are awesome. I measured the cylinders and they are at 83mm. Is the limit 83.5 or 84mm? Also, with the crank, do I need to look for play side to side up and down....not really sure what to look for. This would be my first crank that I have opened up.

 

[Lifted5.4Lariat]

I believe 83 is 1 mm/ Max oversize.. I think 82 is factory. You might be looking at a new sleeve. I recently did this and went through topbore.com and had my reboored and honed cylinders along with a new top end gasket set and pistons, ect for 300 bucks...

 

[Dr Honda]

Yep... a 720 engine should be 82mm... so at 83, it's time for a bore.