[SoakedKarma]

because of the exhaust crossover you may hear air escaping from one valve in both mufflers..
check TDC of compression stroke again..
bent/warped or burnt valve is about the only way exhaust leak would occur on compression/power stroke..

Before tearing into engine I'd pull the oil pressure switch, attach manual gauge to know exactly what the pressure is.

 

[SoakedKarma]

page 2-4 Honda oem service manual

PITA to get at pressure switch

 

[SoakedKarma]

timing chain has spring loaded mechanical tensioner that sticks up under rocker cover.. tap down on it to assure wedges are loose enough to self adjust..

 

[SoakedKarma]

yes both wedges should move.. raising wedge A loosens pressure on tensioner

 

[SoakedKarma]

had my cam chain adjuster jam one time.. had to tap Tab A downward until it broke loose

 

[SoakedKarma]

Tab should move down.. whack down on it with screwdriver handle
I used a small ball peen hammer

 

[SoakedKarma]

BYT (Before YouTube) Old school decarbonization was to trickle water into intake while at higher rpm..
guess some still use it..

Decarbonizing an Engine with Water: Myth or Fact?

I ran across several YouTubes that claim, and apparently demonstrate, that you can clean carbon deposits from a car engine by simply spraying or pouring (very slowly) water into the intake when the engine is fully warmed and running. I've never heard this from a reliable source and my...

www.physicsforums.com

 

[SoakedKarma]

oops, forgot you have a 450
looks like the bore through side cover provides support needed
The 250 Rebel has an inset roller bearing where the shaft passes through left side cover..

 

[SoakedKarma]

Pete has good idea loosening assembly and rotating counter clockwise
is wedge doesn't retract tap it.
Wedge you couldn't move fully retracted along with housing it's attached to in this image..

 

[SoakedKarma]

Have you had a look at the oil filter?

personally I wouldn't attempt 450 engine rebuild as each was custom made.
I would need a machinist to size the bearings as there were 5 different crank and 5 different connecting rod stock bearing sizes none of which are available any more..
certainly wouldn't trust shop technicians that only learned parts R&R.

 

[SoakedKarma]

That is why I ask what the oil filter looks like..
should be able to determine what the metal is within reason and how bad it's become..

 

[SoakedKarma]

keep a clean disassembly, use assembly lube putting everything back together..
Head and cylinder base gaskets are going to be a pain to obtain.
At this point it's worth splitting imo.

cylinders need to be deglazed, I was surprised how pristine the piston skirts looked.
rings are probably OK, I'd like to check end gap.
BUT chance of breaking a ring removing from piston just to check end gap not good, scratch that idea, take what ever blow-by happens while freshly cross hashed cylinders should improve compression slightly..

Damn the torpedoes full speed ahead..

 

[SoakedKarma]

No idea if this excerpt from Honda oem service manual will help or not