Topic: 78 750F valve guide seal removal help - more questions

[filipo]

Hey folks. I posted this in my build thread, but I think best to also post it here.

Got all the springs off and the valves out of my head last night. All of the intake valves were nice and tight against the guides, but the exhaust valves had a little more play. The guide seals were of course toast. So now I'm wondering the best way to remove them. They seem to have two retaining wires, one up top that looks like a guitar string, and a bigger one lower down that looks more like a thin key ring.



I believe I could carve away at the seals with a blade or X-acto knife, but I'm paranoid about gouging bits of the head. Any suggestions?

Also, when looking down at the valve seat, to me it looks like it's been cut away some. Or is this a normal looking seat?



Specifically on the right hand, lower seat, just below where the spark plug would enter the chamber. See how the aluminum looks a little "carved" above the seat proper? Or is this just how they look?

Thanks in advance!

[MRieck]

That is how they look. The top cut of the seat cutter does that and it helps deshroud the intake valve. Make a hook out of a wire hanger etc and pull the seals off. Heat them with a hair dryer/heat gun prior to removal.

[crazypj]

Just take a needle nose pliers and pinch/twist them off
They are scrap so don't bother trying to get them off without damaging them.
 I wouldn't bother cutting anything, you just need them removed so you can fit new ones

[filipo]

Excellent, thanks gents! Just wanted to make sure I didn't screw anything important while I'm in there...

PS Honored to have not one but two Old Timers reply to me... 

[rbmgf7]

A seal puller will pry them right off like a Coke bottle cap.

[crazypj]

Seal puller can damage top of guide

[rbmgf7]

Seal puller can damage top of guide

Which is why you need to be careful. Picking the clips out of the seal first makes it slide out even easier.

[filipo]

Success!

Thanks to all who replied with tips about the guide seals in this and in my build thread. They came off nicely -- well, not so nicely. Like peeling century-old chewing gum off the bottom of a chair. The "pinch-twist" was really the key.



Their removal led to a new question: At the base of the valve guides are some washer-like discs. (See photo below.) These spin freely and do not seem to be attached to the guides themselves. Are they removable/replaceable? Or do they stay where they are?

[rbmgf7]

Their removal led to a new question: At the base of the valve guides are some washer-like discs. (See photo below.) These spin freely and do not seem to be attached to the guides themselves. Are they removable/replaceable? Or do they stay where they are?

The washers are seats for the springs. They come right out.

[MRieck]

Use a magnet

[Chris_SZ]

Hello Filipo.

From your question regarding that spring seat 'washer' I assume you do not have a parts drawing at hand. There are some out there where you can identify things as you go through the disassembly.
Example:

http://www.cmsnl.com/honda-cb750f-750-super-sport-1978-usa_model7240/partslist/E++05.html

Hope this is the right model 

Good luck with the project,

[crazypj]

The spring seats are usually 'held down' by the oil underneath and atmospheric pressure.
 Easiest way I've found to remove them is air jet under edge (I've done a couple of motors over the years )

[filipo]

Hey Chris, thanks for the link. As I told Branden in my other thread, I have several avenues of help: the official Honda shop manual, Clymer, a series of exploded diagrams, and Hondaman's book. But sometimes when I'm in the flow, man, I don't think to check them. To wit: I asked that question, then couple hours later was leafing through the Clymer where I saw the official name and diagram of the "valve spring seat". Easy peasy.

Thanks for the tip CrazyPJ. I've put away the head until it's time to blast it, but before I do I'll pull off the seats with some air.

Thanks again, people!