Topic: Engine rattle noise..Piston or Rod ?

[PeWe]

Blocked oil holes in cam holders? The other holes can then squirt more oil elsewere except cam journal.
Pity that a new good cam of historical value is worn out.

It must be something that block the oil to cam since this has happened twice ruin 2 cams, right?
Or/And a too thin oil and very hot amb temp?

When I got all 4 rods little ends bluished with worn wrist pins, probably caused by overheating and maybe in combination with oil quality/viscocity, cam with rockers looked very fine.
Action Fours SS-1 cam and most likely Action Fours springs.

[Jerry Rxman Griffin aka MuthaF'er]

Frank, what year frame? Don't forget the 10mm offset at the output shaft in case you are using a pre-77 frame.

Clean looking F2/F3 engine!

[754]

Yeah dealing with that too. Gonna try to back the studs out 3/8 if I can on rear.

[Jerry Rxman Griffin aka MuthaF'er]

So if you offset the rear outwards then you gotta deal with the chain guard and the shock vs the chain. You gonna go 630 or 530 also.


In the orange 75 F Weber bike I ended up using a 78 K based engine, CB650 530 front sprocket, 77/78 K swingarm and axle with adjusters, 77/78 K chain guard (F works too), 77/78 F/K rear sprocket carrier and I had a custom rear shock top mount fabbed with that same 10mm offset. Basically everything behind the front sprocket needs to be offset by that same 10mm. Just some things to think about as you think about mixing and matching. Possible but not the easiest. Maybe you can think of another option.

[754]

 If you catch me running 630, get me committed, I have lost it..

I have progressives, I have 3/8 clearance.
Chainguard I made  already notched for the shock body and braced.
And I have brand new ProgShox in the box  so I think I am good.
Everything is pre 76, except the engine..

[754]

 Jerry  you are correct on a lot of that.
 Here is what I did so far. I backed out studs 3/8, but I will go back to about 1/2 that.
 We cut the steel rear sprocket down on the inside, down to .22 thick from .350 or so
 Cut it back 1.2  to 1.25 from sprocket bore. This allows locktabs.
 I may take .10 off the stock nuts
 Made alloy spacers to move sprocket out, .39 thick, 1.2 dia, 31/64 hole thru middle.

This should work with aftermarket shocks and after market or shop Made  chainguard  notched for the shock.
The bad thing, is I probably havevto grind the weld seam off the very end of the swingarm, only about 3/4 of an inch, and just to the sides of swingarm.... so basically , a little bit of the seam.
 One other  glitch , the sprocket no longer centers on its shoulder.  If that becomes a problem, I will chuck it in the lathe, turn the shoulder true, and make a small sleeve.

[bryanj]

Don't forget F2/3 engines have a bad reputation for wearing out exhaust valve guides