Topic: Advice Needed: CB550 Exhaust Valves Snapping Shut

[bryanj]

The genuine Honda manuals are exact copies of the ones supplied to dealers which are written for mechanics so they assume you have at least a basic knowledge of mechanics

[754]

It's good you are reading the manual al ot. The pic shown from manual of rocker interference does seem a bit vague. Asking around about doing this procedure , will usually bring lots of advice.

[Maraakate]

It's good you are reading the manual al ot. The pic shown from maual of rocker interference does seem a bit vague. Asking around about doing this procedure , will usually bring lotsof advice.

Thanks.  I do try to read the technical manuals quite often.  Even for work I never intend to do myself.  I think it's good to be familiar with all of it if it's something you intend to keep running for a long time.

Yeah, I've never known that about the valves.  The best advice I have seen outside of here was over at the dansmc page (which I've also read a lot!) which means to turn things over very slowly and if it feels like something is binding that's because it is and you should immediately stop and inspect.

With that said, I do recall years ago when I put new gaskets on my CM400A that I didn't run into this particular issue with having to hold the rockers up.  But, my dad helped me and that was almost a decade ago so my memory on it is dim.  Maybe he ended up doing part of that for me and neglected to mention it.

[dazemc]

That's the same spring compressor I used and it works fine.

Took me a little bit to find this picture again....

[JWB]

I am guilty of just what 754 said about newbies rushing without fully reading up in the manuals.  I am pretty sure I bent a valve or two just re-installing the valve cover by not lifting the tappets with rubber bands first.  Ugh.  This picture from my Haynes manual shows what I think I did.   Forgot to mention that after re-installing the valve cover I am getting that same snapping valve issue.  Guess it is time to remove the head, remove the valves and see what damage I did.

[JWB]

Received my valve spring compressor yesterday and proceeded to attempt to remove the valves in my 74 550 today.
Once the springs are removed I am assuming the valves should slide out with out much effort.  I am pretty sure I bent every single valve since none of them came easily.  They required more that a couple strong taps with a mallet and a couple had to be driven out with a punch.  I don't see any cracks or breaks in the valve guides, so hopefully I can order all new valves, lap them in and be ok.

[754]

You can slip a tube over them and straighten a bit before removal.

[JWB]

Thanks for the tip 754.
Any suggestions on best place to order a set of valves?

[bryanj]

Ebay search mate but check the valves by rolling on a flat surface before condeming them, its possible they were tight to remove as the tops can "mushroom" with use which needs grinding off

[JWB]

Bryan,
Thanks for the tip.  I did as you suggested and was able to get the valves into the guides about 1\2 to 1" before the got tight.  Gave them a couple rotations and the have a definite wobble.   Ugh, more unplanned work.  Oh well, such it the hobby we have taken up.  If it was easy more people would do it.

[bryanj]

It is very unusual for one fitting of the cover to bend more than 3 valves, perhaps an owner before you did some of the damage and you just got unlucky enough to be stuck with the repair

[Scott S]

Received my valve spring compressor yesterday and proceeded to attempt to remove the valves in my 74 550 today.
Once the springs are removed I am assuming the valves should slide out with out much effort.  I am pretty sure I bent every single valve since none of them came easily.  They required more that a couple strong taps with a mallet and a couple had to be driven out with a punch.  I don't see any cracks or breaks in the valve guides, so hopefully I can order all new valves, lap them in and be ok.

 JWB, PM me. I have some used, stock valves. Maybe not a full set, but enough to help. Might even have a full head.

[bryanj]

It may be cheaper to get a complete used head and all 500 and 550 heads are identical

[MRieck]

 I really question the condition of the guide bores after you forced the valves out. If there was a lip around the valve tip the bore is ruined.

[JWB]

Good suggestions everyone.  Considering sending to Hondaman for an evaluation.
Scott, I sent a PM to you.