Engine problems after 95" build part II - help needed

[Ohio HD]

Pistons are in the wrong hole. There is a front and rear. And I think KB forged pistons have an offset pin if I remember correctly. Read the instructions that came with the pistons closely.

Thanks, will do.

Now I have to get those spiral locks out.... any tips/tricks?

Before you take them apart, read the sheet with the pistons. The intake side has a larger relief in the top of the piston. So both large reliefs face each other in the motor. But both arrows still point forward.

[Adam76]

THANKS, turned the rear piston around and the arrow is facing the rear of the bike, but it looks like it lines up MUCH better. 

The instructions say that the "thrust face" of the piston should point toward the rear of the bike.

The front cylinder went on the piston with no trouble... Could it also be wrong, considering the arrow is also facing toward the front of the bike?

Thanks

[Ohio HD]

Arrows go forward on both pistons. I "think" you have the front in the rear, and the rear in the front.

Hard to tell without seeing both piston tops.

[Adam76]

Arrows go forward on both pistons. I "think" you have the front in the rear, and the rear in the front.

Hard to tell without seeing both piston tops.

Yes instructions say that both arrows point toward the front of the bike... That's why I'm confused.
They also say either piston  can be installed front or rear??

Thanks

[Ohio HD]

Take two good clear photos of the tops of the pistons and post them.

See the two yellow lines? They're the same length. One valve relief is bigger then the other. That's the intake and it must be toward the carburetor side of the cylinder. And the arrow must be forward.


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[Adam76]

Arrows go forward on both pistons. I "think" you have the front in the rear, and the rear in the front.

I've swapped them around and will try again later to install cylinders.

Thanks heaps. 

[Adam76]

Arrows go forward on both pistons. I "think" you have the front in the rear, and the rear in the front.

I swapped the pistons over, same problem. The rear piston is being held off centre. There is a huge gap when the cyl is pushed down on the piston.

Could it be the rear Con Rod?


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[FSG]

post a pic of both piston tops (in the same pic) 

[Adam76]

post a pic of both piston tops (in the same pic) 

Having computer issues, will try again.

[Ohio HD]

Also, what part number are the pistons?

[Adam76]

Also, what part number are the pistons?

I've pulled the rear cylinder because it would not sit right. I swapped the pistons over BUT the rear piston is still sitting too far to the left and therefore puts everything out. No way it's going to work

They are KB Forged pistons KB905C + 40"

I'm about ready to pour gas on this bike and light it up 

[Adam76]

Here is the rear with the cyl in place (very tight as it's crooked).

Can't upload picture. Nothing is working for me today.

[FSG]

did someone say offset

[Appowner]

Here is the rear with the cyl in place (very tight as it's crooked).

Can't upload picture. Nothing is working for me today.

Make sure the pic isn't too big for the web site.  Many sites have limits.

Then get a bigger hammer....

[Adam76]

did someone say offset

Thanks FSG, I saw that info as well.  What are the arrows on the tops of the pistons referring to - front of bike or thrust face (rear) ??

It doesn't matter which way I install the piston it's still sitting way to far to the left to ever work.... Could it be a bent Conrod?

The front went in no trouble...

Cheers for your help

[Adam76]

Either way I install it, the piston itself is not able to be centred in the bore (let alone the cylinder).

The front one was perfect, from the second picture, I'm looking at a bent / offset Conrod??

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[rigidthumper]

Arrows facing the front of the bike, large valve pockets oriented to the intake valves. The center of the rod should align with the case seam.

[Adam76]

Arrows facing the front of the bike, large valve pockets oriented to the intake valves.

Thanks rigidthumper, but thats how I had it set up from the beginning, and the rear cylinder would not go over the piston because the piston sits off centre  no matter which way the arrow points.... What do you think is the issue here? I'm stumped and I don't want to think it's a problem with the crankshaft / flywheels / Conrods. 

[kd]

Adam, that last picture says it all if the angle you took it is true.

[Don D]

How much piston free side to side movement is there in this problem cylinder?

[Hossamania]

Adam, that last picture says it all if the angle you took it is true.

Also, is that a hole in the case at the seam in the first picture?
Edit: and the second picture?

[rigidthumper]

Connecting rods can be straightened in the case. They have brute strength up/down, but much less sideways.

[cheech]

Got anything like a piece of round bar real close to the pin diameter?
Throw it through the SE of the rod and see if it hits the deck square.

[HogMike]

Adam, that last picture says it all if the angle you took it is true.

Also, is that a hole in the case at the seam in the first picture?
Edit: and the second picture?

Stock hole in that case seam, some of the engines have that, it doesn't go all the way through.

Looks like a bent rod, as said above it can be fixed, there is a procedure in the SM that covers that, at least in the older manuals. You can tell for sure with a test pin through the small end.

We've done that over the years especially on older bikes.

[FSG]

Adam, that last picture says it all if the angle you took it is true.

pix can bee deceptive but it's looking like a bent rod to me

put something in the rod to see if it's square to the case,