It started as a Dyna III install...

[Bobbilljim]

So what started as a dyna install turned into a Chain/ auto adjuster r/r. That turned into pulling the LH jug to get a honing and valve clean/lap. Removed the airbox for V-stacks. Replaced Softail HD mufflers with Vance and Hines 4” Eliminator 400s. And now, oil leaking from RH exhaust Valve. I checked and I have wiggle on the Valve. Thoughts on Baking the entire head or localized heating? Press out? Brass hammer drift out? Thanks in advance!

[guzzisteve]

I would take both heads to an auto machine shop.

[Chuck in Indiana]

Maybe K line the guide?
http://klineind.com/k-line-service-tools-4/valve-guide-liner-system/guide-liners

[jwinwi]

One of the best ( and busiest ) Guzzi engine builders drills through the valve guide with a large drill so what's left in the head won't gall the head when removed. Not sure if that's standard practice for aluminum heads but makes sense to me!  Remember there's a circlip around the guide too - not sure how that is dealt with during guide removal...

[wirespokes]

I know a machinist who works on heads and have learned a little from discussions with him. When installing new guides he puts the head in the oven for an hour (as I recall) and cools the guides. The guides, being larger diameter than the hole in the head, are an interference fit. It can be tricky installing a guide while it's cooling the head. If the head cools too much, the hole shrinks and the guide won't seat.

Once the guide is installed, it needs to be reamed. It may have fit the valve stem perfectly before, but the interference fit will cause the inside diameter to shrink and it won't now. If the guide isn't reamed properly, it'll allow oil into the combustion chamber.

It all seems pretty simple, but actually isn't. I wouldn't take my heads to anyone who isn't familiar with Guzzis, or at least air cooled aluminum heads. And I sure wouldn't attempt repairs myself unless there was no other choice for some odd reason. The heads contain the valves, valve seats and guides and spark plugs. What's the big deal? That's the hottest part of the engine, the place where the power is produced, and you've got things like valve seats - steel rings fit into an aluminum casting. They're installed with an interference fit - a few thousandths larger than the hole they sit in. Too tight and they crack the head, too small and they fall out when the head heats up. They have to seat in the head properly or they don't transfer heat from the exhaust valves as well. And then the guide has to be aligned exactly so the valve contacts the seat. Lots of little details that make all the difference between an engine that runs right and one that doesn't or blows up. It's a technology that's right on the edge of being art - the guys good at it have done enough of them to gain a feel for what's right and what isn't. I'm sure someone with machinist training and the tools could do it, but the rest of us depend on the pros.

Drilling or reaming out most of the guide while leaving a small amount on one end makes sense as the way to remove it. Heat the head, then drift out the remains of the guide.

 

[Bobbilljim]

Excellent advice. I found out that a friend of mine has been machining and making his own bike parts for years and he offered to press and ream them for me. I got the Manual and supplement off Greg’s tractor site so having new valves, and guides I’m getting a good deal on a reface, lapping, and replacement.  Thank you all for the wisdom. In other news....

The starter has acted funny since day one. I put a new solenoid on it and no change. So since I have it down for the valve job I decided to take the starter apart using a reference from Bender’s site again. I’ll post some pics below. I learned a new trick from a machinist friend of mine. Best rest-bustin liquid I have ever used from wd40 all the way up to Mouse Milk wich I hold in pretty high reguard. He said to mix acetone and ATF 50/50. It worked like a charm. Maybe even a little better. But boy was it a mess when I got it open... I found a brush holder broken and of course that brush was not puched against the commutator. That might explain the intermittent starter.





boy frog names

[Muzz]

Best rest-bustin liquid I have ever used from wd40 all the way up to Mouse Milk wich I hold in pretty high reguard. He said to mix acetone and ATF 50/50. It worked like a charm.

Ever since Wayne Orwig I believe posted that mix I have been using it.  Works great.

[Bobbilljim]

Wow, I wish I had Found it sooner! It is Awesome!

[wirespokes]

I originally got the data about ATF/Acetone and tried it. I had difficulty getting the two to mix. They separated in the jar.

So I'm curious how you did it. Is it a situation where the Acetone is slowly mixed into the ATF?

Eventually I just mixed the two where it was needed.

Also, I found out recently that the original guy who discovered the combo, mistakenly listed it as ATF when in fact, what he used was power steering fluid. I haven't tried that yet.

[Muzz]

mistakenly listed it as ATF when in fact, what he used was power steering fluid. I haven't tried that yet.

Same stuff, unless you have a Euro car that uses horribly expensive synthetic fluid.

As far as the mixing goes,  yes, it does tend to separate out.  I have it in a smallclear plastic squirt tube.  Just shake it vigorously before use.  It doesn't separate out that quickly.

[Furbo]

. And now, oil leaking from RH exhaust Valve. I checked and I have wiggle on the Valve.

Can you explain this a bit better? Did you mean valve cover? Or Valve?

What's mileage?

[Chuck in Indiana]

Can you explain this a bit better? Did you mean valve cover? Or Valve?

What's mileage?

I'm sure he means the valve. It doesn't take very much oversize on the guide to see movement from side to side on the stem.

[Bobbilljim]

I'm sure he means the valve. It doesn't take very much oversize on the guide to see movement from side to side on the stem.

sorry i’m slow to respond.

Yes, valve itself. the limits in the book if i recollect are .314ish and i measured .319. i used ball gagaes and a micrometer.

I mixed the two 50/50 in a squirt bottle special for chemicals I found on granger...

https://www.grainger.com/category/wash-bottles/labware-bottles-and-jars/labware/lab-supplies/ecatalog/N-19zv

[Furbo]

sorry i’m slow to respond.

Yes, valve itself. the limits in the book if i recollect are .314ish and i measured .319. i used ball gagaes and a micrometer.

I mixed the two 50/50 in a squirt bottle special for chemicals I found on granger...

https://www.grainger.com/category/wash-bottles/labware-bottles-and-jars/labware/lab-supplies/ecatalog/N-19zv

Well, if everything else looks OK, put it back together and reinspect it in 30K miles.......just one persons opinion.

[Bobbilljim]

To late for that. The valve guides are already out and new ones are getting pressed in. But in other news I am rebuilding the Bosch starter and that is going well. Except for the nose had a crack where the bushing is so Carl Harper has an old one I bought off him. When that gets here that should be the last bit for the starter. ah well...

[Bobbilljim]

I got the head back and it looks great. The valves have the proper clearance and he even shimmed the springs for me. It’s all going great. Got the rebuilt starter installed after a quick bench check. Now if I can get the mufflers out of customs in San Fran from TLM I’ll be in good shape.

So if someone were to do the valve guides in the future, either buy all the equipment to do it correctly and a couple used heads to practice on, or take it to a machinist. I have been wrenching for 30 some years now and the last 20 on airplanes. After seeing the tooling and focus this guy has, and the job that came out, there is no reason for anyone to attempt this job. I am grateful for the seasoned wisdom on this blog that most likely saved my head and my arse!! Thanks guys!

[Kiwi_Roy]

The starter has acted funny since day one. I put a new solenoid on it and no change. So since I have it down for the valve job I decided to take the starter apart using a reference from Bender’s site again. I’ll post some pics below. I learned a new trick from a machinist friend of mine. Best rest-bustin liquid I have ever used from wd40 all the way up to Mouse Milk wich I hold in pretty high reguard. He said to mix acetone and ATF 50/50. It worked like a charm. Maybe even a little better. But boy was it a mess when I got it open... I found a brush holder broken and of course that brush was not puched against the commutator. That might explain the intermittent starter.





boy frog names

What a bloody mess, it should be as dry as a bone in there, clean as a whistle, I have never seen one like that before.
Grease on the commutator is a No,No, it interferes with the current flow, there should be none in there at all, I can't even figure out how it got there it doesn't have a grease nipple.
Take a look at the armature, it looks shiny as though it has been rubbing on the poles, they do that if the bushes are worn out, it looks as though someone has pumped grease in there to compensate for lack of a bearing.
The armature thrashing around probably contributed to the brush/brush spring problems and the cracked nose piece.
A pair of new bushes will cost you a couple of dollars, they are sintered bronze, to prepare them you place it on your finger fill it up with oil then squeeze with your thumb until the oil seeps out through the pores in the metal thats all the lube it needs apart from a few drops of oil now and then.
When the commutator gets a hard black finish on it that will last forever, leave it that way.
New bushings every 20 years or so and a change of brushes every few years and these old Bosch starters will run forever.

Dump the whole thing in some sort of a degreasing bath, or a high pressure washer, I don't think whatever you do to it can make it worse.
If you need to drop the fields out, you need an impact driver for that.

That takes the prize as the worst starter I have ever seen.

Here you go $10
https://www.euromotoelectrics.com/Starter-Tune-up-Kit-BMW-MG-BO157-TK-p/bo157-tk.htm

[Bobbilljim]

Thanks Roy! Well, turns out it wasnt grease but a mixture of oil and dirt and brush. The oil is coming from the tranny seal:( Oh well, time to call in the experts cause I dont do transmissions.....

[Kiwi_Roy]

Thanks Roy! Well, turns out it wasnt grease but a mixture of oil and dirt and brush. The oil is coming from the tranny seal:( Oh well, time to call in the experts cause I dont do transmissions.....

Wow, I'm glad in a way, hate to thing anyone would pack it with grease.
The bearing has probably failed taking out the seal, My Bro Kiwi_Kev just did the box on his California
The transmissions are a lot less daunting than you might think
Pete Roper and John Noble have posted excellent tutorials on Greg Benders site

[Bobbilljim]

Roy,
I have read through those and the more I read the braver I get. Its nice to have a few guys near by in case I get in a pinch. I think Bender is just North of me and a few more around here in Phoenix. If nothing else I could save myself some labor and do the remove/install and cleaning it up before it goes somewhere. We’ll see. Ive done a handleful of car motors and airplane engines so I’m used to the tolerance and such. Its the fear of the “boing” and parts flying apart without knowing what i lost. No videos to be found either. Maybe i’ll rent a high speed video camera for disassembly?

[Kiwi_Roy]

This little ball I found rolling around the floor had me scratching my head for a while

[Bobbilljim]

Hmmm.... Steering bearing ball, or the little one out of the carb jet? Good luck!

[Kiwi_Roy]

Hmmm.... Steering bearing ball, or the little one out of the carb jet? Good luck!

No, its out of the gearbox, an important part