How to remove Head Dowel Pins 'A'

[Kool_Biker]

Is there a trick to removing these surprisingly tight dowel pins, without damage to themselves OR the head?

P1070014.jpg

Cheers, Aris

[zxbob]

You could try and gently grab them with a set of needle nose pliers - I just did a cam swap
in my bike and allmost all of them came out with the cam caps or by hand.

A couple of mine required a slight twist and lift with my needle nose.

Bob

[cbx6ss]

When I asked the same q awhile ago, I was told "leave them in unless there is a reason to remove them."

[6Pipes]

Not sure why you want to remove them Aris but you could try dry ice. That should shrink them down a bit.

[barryadam]

Aris,

If you need to grip them without damaging the OD, try an appropriate size thread tap.
The tapered kind. Preferably an older, spare one.
Just use it to grab the ID, not to fully tap threads in the collar.

Barry

[Kool_Biker]

When I asked the same q awhile ago, I was told "leave them in unless there is a reason to remove them."

I need to repair (helicoil) the threads just below them, in a couple cam bearing holders (for lack of better words).

BTW any one know why perhaps I should avoid this?
Seems straight forward enough to me notwithstanding removing these stubborn dowel pins and respecting max depths

Aris

[Kool_Biker]

Aris,

If you need to grip them without damaging the OD, try an appropriate size thread tap.
The tapered kind. Preferably an older, spare one.
Just use it to grab the ID, not to fully tap threads in the collar.

Barry

Clever!
Seems an M7 tap would fit best; typically I have an M6 and M8 so will try later.
I must say though, they are stubborn. I have tried my heat gun, not in anger as I am worried about heating the head too unevenly, and they will not budge.
I could, of course, try our oven ...

[daves79x]

Aris:
No problem repairing threads there if you are careful. As for removing the dowels, the tap trick sounds pretty neat, and along those lines, I've found a bolt that will just go inside the dowel and then gripped the dowel with pliers. With the ID 'full' you won't crush it. The marks you leave can be worked smooth again, but any you really mangle, can be replaced - they are still available from Honda.

Dave

[Jeff Bennetts]

Aris, just be careful how far you drill into the head for the new insert. When I rebuilt Ian's 79 the previous owner had stripped a cam hold down bolt and just drilled through the head and secured the cap with a bolt and nut on the outside of the head, I had to have the head welded before fixing the threads .

You can fix these fragile cam bolts that seem to twist their heads off after re-using by replacing them with studs.

Funny thing Aris, Ian's motor had to be stripped down to every last nut and bolt, oil pump, trans gears, clutch assembly you name it, it got disassembled because when I removed the cam cover I found wood shavings in all the oil pools.




Pic of head with studs.

[Kool_Biker]

When I rebuilt Ian's 79 the previous owner had stripped a cam hold down bolt and just drilled through the head and secured the cap with a bolt and nut on the outside of the head, I had to have the head welded before fixing the threads .

Jeff

I am amazed at the abuse some of this engines will endure!!!

Love the 'studs' idea, these cam bolts are indeed a pain.
And what downright amazes me, is how I have never managed to break one, outright. They will sheer, but will always come out in one piece! Some physics I am failing to grasp!

DSC07546A.jpg

But all's not bad. I have noticed, the new ones supplied by Honda under the same P/N seem to be much -much better.
So I just always make sure I have a few spare bolts around , short and long.

Aris