G2 Engine Rebuild about to start

[J-ROB]

Originally Posted by CP241

kinda hard to tell from that picture, can you post a picture from the sides?

one will be shiny. one will be dull

they both look the exact same from the side

[jclark138]

Originally Posted by J-ROB

I'd say so! looks like the valve cover gasket was definitely leaking!!

Yes, a bit! Plus fine dust here and pine needles. Getting some screening upon re-assembly

[jclark138]

So, power-washed the engine with carb, shrouds, etc. removed. This piece shoots off into the weeds.
A) what is it ? 2) where does it go ?
( not much for cataloging. . . )

[J-ROB]

Hey Jeff, that piece goes between the fins, behind the fan cover sort of... Let me see if the parts diagram shows it well enough, or I can take a picture of mine.

Glad you saw that piece fly off! I knew it was there and still forgot about it until it fell off mine last night once I already had the motor apart!

[J-ROB]

Here are the pictures, that piece sticks in the fins under the piece of the shroud that covers the flywheel/fan.

I haven't cleaned mine yet, so you can see in the third picture where the plastic piece touches against it and in the fourth picture, you can see the piece that goes over the flywheel has a curved edge that matches the mark on the little piece. The piece in question is basically rectangular with a little tab sticking off of one side, that tab points down if that helps at all.

[J-ROB]

The parts diagram didn't show it well enough to make out where it would go, but if you want to check that out, here's the link.

https://shopyamaha.com/parts-catalog...AIR_SHROUD_FAN

I guess the above diagram doesn't show it at all, it's part of the crankcase diagram, but as the diagram is drawn, the piece goes on the back side so its not much help.

https://shopyamaha.com/parts-catalog...1-e7a89ac14184

[jclark138]

Thanks - that helps a lot. Glad I saw it too. I know how long a VW engine lasts without the little tin under/between the cylinders. . .

[J-ROB]

Hey Jeff, ya done yet?

I am!

Fire in the hole!!!!!

[J-ROB]

Finished the rebuild last night, thought I would have been done Friday night, but I wanted to take my time and clean everything up nice, and triple check the manual as I went.

I HUGE thank you to CP241, Chris, you were a big help, thanks for all the advice on how to do certain things without specialty tools, I appreciate it!

Not only was the engine burning oil, it was leaking a lot too! The crank seal on the clutch side was pretty ate up, the crankcase gasket was leaking, and it looks like we were leaking oil from the front of the cylinder by the pushrods at the head gasket.

Here are some pics from the tear down, the rod bearing and crank looked great. The camshaft looked nice too, even though I didn't get a pic of it. All of the internals looked great with minimal wear.

There was a fair amount of carbon in the combustion chamber, and about an 1/8" thick on the intake valve. Cleaned up the valves with the wire wheel on my bench grinder, and actually clamped the cylinder head between two boards in an old bench vise and took the pressure washer to it once fully disassembled. It did a good job cleaning it up, also was able to knock out almost all of the carbon from the exhaust port as well!

[J-ROB]

Some more pics from teardown, there were quite a bit of vertical marks in the cylinder wall, they were practically gone after running a hone through it.