Damage assessment [pics] (washer in carb) 97 spx

[microzee]

Hey guys, I've made the mistake of my lifetime. I was tuning my beautiful fresh water low hour spx 97 and decided to leave the bolts on where the flame arrestor attaches. During tuning, the bolt wiggled out and I found it in the engine bay. The washer was no where to be found, and the engine developed a pinging then a harsh noise.

I tore down the engine and this is what I found.
Cylinder head, pto side damaged:



Piston head, pto side:



rotary valve/plate:



inlet port:



This is all very unfortunate given it was running pretty well after the carb rebuild/fuel system overhaul.
I have pulled the engine and am currently working on inspecting the bottom end.

With a tight budget in mind, my questions are:
1) Do I need to replace the cylinder head, or is that something a machine shop could clean up and it would be fine?
2) Same question for the rotary cover, could it be resurfaced?
3) Also for engine scoring around valve inlet, can this be resurfaced?

I clearly need to replace the rotary valve and the piston.
4) Can I purchase a used piston off of eBay and replace it with that?
5) If yes, do I resuse old rings/purchase new?
6) Do I need to do any work on the cylinder, i.e. hone or is a bore likely as well? (assuming used piston)

It looks like OSD parts doesn't sell an OEM gasket kit for 787 anymore.
Has anyone used the BSD aftermarket kit for $70? link here.

I've found most of these parts used on eBay all for reasonable prices.

Thank you!

 

[mikidymac]

The head is fine, just file down any high spots.
The crankcase and cover are fine as long as there are no grooves connecting the two intake ports.
Do not buy a used piston.
If the cylinders look fine just hit it with a ball hone and instann new STD. size pistons. Pro-X is good and so is WSM.
I would buy a complete WSM gasket kit with seals.

PWC Muscle can help you out with WSM parts. @hfgreg

 

[microzee]

Thank you for the info. I shot @hfgreg a PM, is this the best way to get in touch with him?
As for the bottom end, as suspected the brass rotary gear has had its teeth sheared off, metal everywhere. I went ahead and purchased a good condition used OEM off eBay. Anything else important down here I need to inspect? From initial lookover everything else seems fine for the most part.
Also, while I have this engine apart, are there any mods you recommend?





Noticed this seal on the counterbalance looks worn/not in the right place?

 

[mikidymac]

Nope, no mods, just make sure everything is spotless.