Valve Guide Removal... please help me!

[xsjohn]

The new guides are in the head....right........and when you put the valve in the guide and push the valve flush with the seat on the head it gets snug....?.....all of them....just one.....?...can you move them around to make it right....did you clean the valve stem well..is there any burrs on the beginning of the opening on the guides....before I say any more.........

xsjohn

 

[yamaman]

I take it you've read page 23 HERE

 

[Sundie]

about filing the tips from mushrooming? New valves... Wouldn't think you'd have that issue. BUt yeah, doing the tips would cause no other issues, since they stick out anyway.

 

[cheftay]

john, i've got the new guides in the head, yes. my problem comes when i begin to slide the valve through the guide... what happens is it stops sliding right when the tip of the valve stem reaches the other end of the guide( right where the seal is). So the valve doesn't even get a chance to make it to the seat.
There are no "noticeable" burrs on the ends of the guide but maybe reaming them with that 8mm special tool(pg 23 of above link) would be a good idea.

yamaman, i have read that before but I haven't measured the seats or anything to check for proper degrees...

again... new valves, new guides, new seals, old springs, new o-rings, and new rocker feet as soon as i get the valves in.

thanks for trying to help me solve this guys!

chef

 

[Jack]

If you drove those guides in with a hammer,most likely you've mushroomed the upper end,just get'em resized.

 

[cheftay]

well I did you the installing tool and a hammer but you're probably right.
You think it'd be a good idea to take the case to a machine shop and have them check the valve seat angles and ream the guides?
I don't have any of the tools needed for any of those things...

Thanks!

chef

 

[inxs]

- did you mark the valves l n r...you will need to at least lap them in, getting them refaced will never hurt, esp if youre not sure which cylinder they came from

 

[Sundie]

inxs: he got new valves

cheftay: absolutely. The valve seats will definitely need to be recut, at least lightly, and then lapped thoroughly. If you hadn't replaced the guides, you could probably get away with lapping. Me, having done it a bunch of times, would probably lap the valves by hand, and check the pattern to determine if they needed cutting. But i've got the tools for that.

 

[cheftay]

Yep the valves are new.

Yeah Sundie, I see what you're saying... I don't know if I would trust myself doing it for the first time on this engine though just because I don't think i'd have a whole lot of room for second chances..

I ran into a guy at the hardware store today that has two XS650's and he told me of a good machine shop near me that the owner races BSA's but he's really familiar with the XS also, so I'm gonna look into taking it there.

 

[cheftay]

Talked to the guy at the machine shop and he said to do cut the seats and ream the guides would be about two hours and $140 bucks.... is that a decent price?

I figure it'd cost me about 120 bucks to buy the valve kit from mikes and do it myself...

 

[KevC]

If you have only caused a slight burr at the top of the valve guide from fitting, you could very gently "break the edge" using a chamfer tool by hand. use next to no downward pressure & keep trying your valve. you dont want to create a chamfer, just remove the burr.
Dont know what others think, just using 35 years machining experience

 

[Sundie]

Kev: i agree with you, but he still has to reface the valve.

Chef: It's even odds. Do you think you'll be doing this again in the future? Me, i service several friends XS650's, so the tool made sense. After the 2nd guy bought me a case of beer for cutting his seats for new guides, it had paid for itself.

 

[cheftay]

hmmm yeah, I don't really see myself needing to do any more valve seat cutting anytime soon.
Machine shop it is

 

[angus67]

when I had my head done, the guy cut the seats, lapped the vavles, shimmed the springs for 50 bucks, but, I hadf also heard he had a soft spot for 650's, and prolly figured I needed all the help I could get, being as this is my first rebiuld.
When I 'baked' my sleeves to get them out of the fins, I thought my oven blew up when they fell!!

 

[Sundie]

That's an awesome adrenaline high, innit?

Chef : Also "shimmed the springs" - springs have a certain height/pressure specification. i think it's 75/150, but i forget the heights. So, when Angus said "shimmed the springs", he means the guy measured the springs, found them a little bit lacking, and put a couple of shims at the bottom to bring pre-compress them, and bring them back to life. Ask whomever you take your head to to do all what Angus mentioned.

 

[xsjohn]

Been watching this thread..........as of yet I have not experienced any valve guide problems or spring problems either...at 76 thousand and climbing.......might be good not to mess with them unless a real problem exists........once you dive into them you do have to dig yourself out......now valve tips are another story.......

Same thing goes for lifting the cylinders when there is no problem just to measure the clearances and creating a new problem by expanding the clearances with a hone and new break in......I watch this every day........goodby longivity.......pull the pins if compression is decent.......

..xsjohn

 

[Sundie]

John: if he hadn't put in new guides and valves, i'd generally agree with you. And you have to admit that checking spring rates and shimming if appropriate (since you're in there anyway) is a good thing.

He's already got the whole top end apart anyway, so he might as well do it all right - and then be able to go those 10's of k's without having to look at it again.

 

[cheftay]

Speaking of going 10's of k's more without having to mess with it again, should I just get rid of my stubborn attitude and replace the cam chain? The only reason why i didn't is because I don't have the riveter so it'd cost a little more than just buying the chain...

I already got the head back, And the guy re-installed my valves and everything for me, not sure if he shimmed them though, I might call him and ask him instead of taking them out again.

The guy I took it too used to race old BSA's back in his day...

 

[inxs]

- a chain riveter is nice if you have one, however ive done dozens of chains with a hammer and spreading punch or cold chisel or even a peening hammer if your careful...brace the link from behind with a solid block, to take the impact

 

[Sundie]

Chef: i wouldn't touch them, unless: Stupid question: he installed your new valve seals too, right? If he didn't, okay, do that. Otherwise, a professionals work should generally be trusted.

On the other hand, calling him up to ask stupid questions (just preface with "hi. this is a stupid question, because i'm learning") - i've never met a *good* mechanic who minded that.