Today I broke a valve guide

[Ajohnson]

Let me introduce myself by saying im just beginning my GS journey, got an old clunker to bring back to life this winter. This is my first excursion into motorcycle mechanics, ive done plenty of small engine work and have a friend with professional experience to help me.

Realistically how difficult is this broken valve guide going to be to remove? Will the generic 'valve guide removal tool' that you pound with a hammer work?

[Nessism]

Removing a valve guide is not a trivial task. The valve seat will have to be cut after replacement, for example, because there may be some misalignment created. Also, the ID of the guide reamed to exacting dimensions. That right there typically puts the job into the realm of the pros. Also, depending on how the old guide is removed, and some luck, you may need an oversize valve guide. It's not uncommon for some aluminum material in the bore of the guide to be lost when the old guide is removed, and when that happens, the hole needs to be reamed, and an OS guide installed. Using heat before removing the guide is helpful, but that in itself is not easy either. If you have an old oven, put the head inside for an hour to heat it up before removing the guide, that will expand the aluminum, and reduce material loss.

[chuck hahn]

375 TO 400 for half hour or so is what i use in my buddies powder coating oven to remove them. As Ed said the replacements are 12.2mm and the applicable reamer is needed to resize the hole. Resize and rehear head to insert te new one. And oil the new one when tapping it home and be sure the stop retainer clip is on it. Ask me how i know.

[Ajohnson]

Certainly I could just heat the broken guide and the area around it with a torch?

[chuck hahn]

Its iffy. The idea is to expand the metal as much as possible. Since aluminums such a rapid displacement of heat its better the whole things heated. Plus youll be there forever with a torch.

[Ajohnson]

Thats fair. I looked up the price of the work at a machine shop and it seems somewhat reasonable.

on the other hand i could find a spare motor for sale elsewhere. I have this one tore apart tho, snd the goal was to tear it apart and put it back together for the enjoyment of doing so. I do suppose a cylinder head could be found separate of a whole engine too.

My mechanic buddy was giving me a hard time, he said I could just find a good running bike for what im gonna have for work in this one but for me the money isnt necessarily the point. I can put 1000 this winter into something I paid 200 for, or go buy a running bike for 1000 bucks I suppose.

I just want to tinker on something and learn a little bit in the process.

[Redman]

Welcome to GSR.

[Redman]

I would be interested to know what it took to break the valve guide like that.

Reason I ask is because I had a small shop replace valve seals and lapp valves on a head (1100G), and two valve guides broke in the process. So they were replaced. I didn't understand what happened to break the valve stem(s).
Also...... And now, only 5thou later, the engine oil usage is really bad, blows more smoke on startup (if sat for a few days) and smokes on decell...... both much worse now than before the rebuild.

[rphillips]

Well First, Welcome. Second, Thanks for introducing yourself. Third, I don't see where you introduced your bike. We'd love to hear a little about it, and we've always been known for enjoying pictures.

[Nessism]

Broken guides can occur when suitable care isn't applied during seal removal. Not saying this happened here, but it's known to happen.