V-Twin Forum banner
1 - 16 of 16 Posts

·
47,503 and adding
Joined
·
193 Posts
Discussion Starter · #1 ·
When disassembling my heads, do I need to find TDC to remove the push rods? Or is it only important on install to make sure there is no load on the rods? I know that doing one head at a time is important, I just wonder how I would know TDC without being able to see the piston position.
 

·
Registered
Joined
·
141 Posts
Yes you need to unload the valve train. My manual has a big caution that says "Removing the rocker arms with the valve train loaded can result in bent push rods, damaged bushings or warped support plate." Finding base circle: rotate engine until piston is at Top Dead Center of the compression stroke. Stop engine rotation when the flow of air through the spark plug hole stops. Direct the beam of a small flashlight through the spark plug hole to verify piston is at TDC. Thats from the manual, but when I was doing it by myself I just put a long straw into the spark plug hole so I could watch it, after I had it close of course.
 

·
47,503 and adding
Joined
·
193 Posts
Discussion Starter · #4 ·
That's a great idea to use a straw. I will use that. Do you normally remove the push rods from both cylinders before you take either of the heads off? Just to get the tubes out of the way, it would seem to make sense.

Thank you for the straw trick.
Larry
 

·
Premium Member
Joined
·
946 Posts
I believe you said that you weren't going to remove your cylinders. If you are not you should put a couple of spacers on 2 of the cylinder studs and screw on 2 of the short head bolts this will keep your cylinder from lifting when you rotate the engine to get to the base circle on the second cylinder. Springer posted a pic of the nuts and spacers I'll see if I can find it.
 

·
Registered
Joined
·
141 Posts
I used 1" PVC as spacers instead because I dont have old wheel spacers. 1 1/2 inches for the short bolts and 2 1/2 inches for the long bolts.
 

·
47,503 and adding
Joined
·
193 Posts
Discussion Starter · #10 ·
Thank you for the great ideas. I guess I was trying to take the shortcut and not replace the o-ring base gaskets. It appears that maybe I should reconsider and change them anyway. I will have help to hold the cylinders and pistons while I remove the circlip and pin.
 

·
Premium Member
Joined
·
946 Posts
If you are going to take the cylinders off you just lift them off no need to take the pistons off the rods if your not changing them. Lift the cylinders a bit and put some rags under them to keep anything from falling into the lower part of your engine then just slide them off. Be careful not to let the piston bang against the cylinder studs when the cylinder comes off. Get some 1/2" rubber tubbing or hose and slide it over the studs . This will let the piston rest there without hurting them or the studs.
 

·
47,503 and adding
Joined
·
193 Posts
Discussion Starter · #12 ·
I thought that the rings shouldn't come out of the cylinder since they are broken in together that I had to keep them together?
 

·
Registered
Joined
·
141 Posts
Swami says "I see a stage 3 big bore in your immediate future." you know its the ol' "Well as long as I'm in there anyway, I might as well....."
 

·
Premium Member
Joined
·
946 Posts
If you are going to have Big Boyz do your heads, call Bean and ask him if you should leave the pistons and rings in the cylinder or not. I have sean posts saying that either way is OK.
 

·
47,503 and adding
Joined
·
193 Posts
Discussion Starter · #16 ·
I did talk to Bean about the cylinder base gaskets and he said he's done it both ways and not had any trouble. He did however, tell me that if I do decide to replace the gaskets to keep the pistons and rings together and pull the circlip and remove the cylinder and piston together.
I am at 95" Stage II with a 42MM Mikuni now. I just need to get the money together to have Bean clean and port some heads for me.

Larry
 
1 - 16 of 16 Posts
Top