G9 Rebuild Time

[Paulzy123]

Originally Posted by raydhd

No the shell bearings inside the connecting rod . Part # 9 in the drawing.

Lol, was just going to ask..

Thx for the clarification.

[Paulzy123]

Took a step forward that has thrown me for a loop.
Removed the crankcase cover.
And from what I thought I read, the dot on the lifter shaft should meet the tooth on the main gear and also the dot on the balancing shaft too and the piston at middle.

Well none of those exists. 🤷*

Also still can get the pesky fan off, but I see some threaded holes, maybe just find the correct threaded bolts to push it off.

[raydhd]

I think you find the marks when you clean the parts up. The flywheel will come off with a universal puller. I think the bolt needed for that was a M8

[Paulzy123]

I pulled it more apart.
Correct the cam shaft dot does line up with the dot on the main shaft.
The balancer did not. It was off by a 8 or so teeth. So I’m guessing the engine has run off balance for a while.

Piston is out.
Cylinder and piston “look” good.
Will have a machinist check for sure tho.

And of course my pulley puller was borrowed by somebody.

[CP241]

Yes, the cam and crank marks look good. The balancer that dot just lines up with the tooth pointing at it, it’s off. I think there was originally a paint dot or something there but again, can’t remember 100% as it’s been a minute since I rebuilt one of these

There appears to be some pretty heavy scoring on the piston and the cylinder. Can you feel those with a fingernail? Sometimes they *look* much worse than they are but those look pretty bad. I think I’d plan on an oversized piston and rings, and have the cylinder overbored. The machine shop will want the new piston and rings before they will bore the cylinder so they can match specs appropriately.

Any machine shop that will bore a cylinder WITHOUT having the piston and rings before doing it will never get my business.

[Paulzy123]

I ran my fingernail in the cylinder and on the piston.
Cylinder is smooth as far as I can tell.
The piston definitely has gouges in the top side.
Checked the cylinder where the gouges would be, and no feelable or seeable damage.

Thinking it best to do as you stated and get her bored out.

Question then is how much bore?
Parts lists shows 2 options. .25 and .50 mm.
I guessing less is better?

Once bored do I need to hone it too?

[CP241]

Bore as little as possible/necessary. .25mm

This will give you or someone else the opportunity to have it bored to .50mm later down the line

[Paulzy123]

Originally Posted by raydhd

The flywheel will come off with a universal puller. I think the bolt needed for that was a M8

M8 was correct.
But boy that flywheel is on tight...
Gave the puller all I can do with my johnson bar and she not pulling off.
Would it be a bad thing to use my impact gun? I don't want to damage anything.

[raydhd]

Vibrate it in a safe spot with an air chisel. My clone flywheel was stuck. Seen that trick on youtube. A couple of quick burst and the flywheel popped loose.

[CP241]

Those flywheels are a sonofabeech to get off. They’re ALWAYS stuck on there like crazy.

I use a puller. Get it as tight as I can by hand. Then a couple quick hits with my impact gun. Leave all the tension on it from the puller and smack the tightening nut on the puller a few times with a good hammer to jar it. Keep repeating until she pops off.

Fortunately, it’s usually rather uneventful when it does let loose. Not like a wheel bearing when parts go flying and stuff. Moves like a centimeter and then you just slide it off. But you may want to stand offset to the side when you whack it just to be safe