Topic: 1973 CB350F "Modest Original" build

[iiAtlas]

You may want to keep the plugs in and fill-up each combustion chamber w/ acetone and let it soak for a while.. I would remove the carb. rubber manifolds first w/ that impact and a helper holding the head down.You can remove the valves(are you going to do your own valve work? otherwise the machine shop can remove the carbon)later to clean them up along w/ the ports and valve seats..

One man + 5000 forum member show here!  I'll be doing the valves.  Plugs are in.  I didn't want to soak until I removed the carb intake boots.  Need to find a helper to hold the head down while I work on them with them with the impact.  Thanks for the tips!

If I were nearby I'd be happy to help, but those carb boots... I'm glad I "had to" buy a new head or I a lot more curses would have exited my mouth    Do you plan on reusing the boots?  If not, a torch is a very good idea.

Hah! Thanks for the offer.  I do plan on reusing, unless I can source some relatively cheap OEM ones.  No noticeable cracks, though they are quite hard.

[iiAtlas]

Carb boots are OFF. 





This little hand impact from Vessel (link) made short work of the bolts.  Pricy, but worth it's weight in gold!  A welcome addition to my tool box.



Have the head soaking in EvapoRust now.  Will give it a two hour soak and see where its at.  I angled it slightly in an attempt to reduce the the valve "bowls" from simply filling up with air.





More soon!

[grcamna2]

You got them off w/o breaking the screws  I like that Vessel impact

[sbeckman7]

Agreed, that's impressive man! Nice work.

[iiAtlas]

You got them off w/o breaking the screws  I like that Vessel impact

Agreed, that's impressive man! Nice work.

All credits to the manufacturer!  I merely wielded the whip

[iiAtlas]

An update -



The evaporust did something because it sure didn't look this color before!  This was about a 2 hour soak, near the low end.  The bottle recommends 1-12.  I didn't feel comfortable leaving it overnight due to the potential of chemical stains so I decided to remove it and try the scotch brite again.  Ehh..



It worked okay, but no better than the Berkabile 2+2 gum cutter.  The stuck parts were still stuck.



I think if you let this product run its course over the full 12 hours it would work well.  You can see pretty clearly how it did on the raw metal in this picture below.  Only the bottom half was in the evaporust.  The best part is that this solvent gives off no fumes and is easy to handle.  I simply used nitrile gloves and had no issues working with it sans mask.  I wore goggles as I'd rather not get it in my eyes, but it doesn't cause instant blindness like some of these other evil solutions.



I rinsed it off, blew it dry with compressed air, put the spark plugs back in and now I have the valve seats sitting in Simple Green aircraft cleaner.  This is much more potent and should be equivalent to sitting it in the Berkabile gum cutter over night.  I'll be waking up at 6am to have a look!

[grcamna2]

Looks like progress is being made.I sometimes use a small Forney brand blue plastic handled SS wire brush plus a small screwdriver to gently scrape/brush off the heavy stuff and it will clean it good. 

[iiAtlas]

Looks like progress is being made.I sometimes use a small Forney brand blue plastic handled SS wire brush plus a small screwdriver to gently scrape/brush off the heavy stuff and it will clean it good. 

Screwdriver, good tip.


Another update...  Something must've worked because they certainly didn't look like this last night!





I dumped the solution and bathed the top of the head in some warm water.  Progress, for sure, but again still some work to do.



I got to it with the green scotch brite and my brass wire brush (much like the one above). 





This was about 30 minutes worth of scrubbing and brushing.  My scotch brite had worn down to nothing and the remaining carbon was on their pretty solidly.  I decided another days worth of soaking in aircraft cleaner wouldn't hurt.





As always, more updates soon

[grcamna2]

Looking good man  Some of those heavy deposits won't really come off w/o scraping & don't be concerned about using a SS brush to remove stuff too;the brass brush will only polish stuff.

[iiAtlas]

Looking good man  Some of those heavy deposits won't really come off w/o scraping & don't be concerned about using a SS brush to remove stuff too;the brass brush will only polish stuff.

Thanks!  Only scotch brite (green and red), solvents, and a brass wire brush so far.  The brass brush is pretty lame, but I've managed to make it work somewhat well by spraying the Berkabile gum cutter, letting it soak for about 30 minutes, then going at it with the gum cutter still in there.  More progress...







One more soak and we should be there!

[iiAtlas]

Progress, but not perfect.  Having a hard time removing that remaining white stuff from the exhaust valve.  Should I just keep going at it soak + scrub?  Or do I have something which will pack more of a punch.

[grcamna2]

That cleaning job is Top Notch  !
You'll need to scrape off the rock hard deposits on the exhaust valves.

[iiAtlas]

That cleaning job is Top Notch  !
You'll need to scrape off the rock hard deposits on the exhaust valves.

Thanks!  It'd be nowhere near this without you lot.  Definitely a test of patience, but the rewards are satisfying.  What tools can I use to scrape at those deposits?

[grcamna2]

Looks like progress is being made.I sometimes use a small Forney brand blue plastic handled SS wire brush plus a small screwdriver to gently scrape/brush off the heavy stuff and it will clean it good. 

[iiAtlas]

Looks like progress is being made.I sometimes use a small Forney brand blue plastic handled SS wire brush plus a small screwdriver to gently scrape/brush off the heavy stuff and it will clean it good. 

Hah..thanks, sorry.  Could definitely use a coffee right now!...

SS being stainless steel correct?

[grcamna2]

Yes Stainless steel  I like that Forney brand blue brush style stainless steel much better than the wooden handle small brushes or the China black handle ones.You should be able to find the Forney brand where welding supplies are;I had a little trouble getting them locally but finally found a good source.I use them for cleaning all kinds of rusty or corroded metal parts(they also work good on cooling fins and spokes)and they are excellent as you can go hard with them to remove junk or soft and then they'll be good for polishing a bit.

[iiAtlas]

Yes Stainless steel  I like that Forney brand blue brush style stainless steel much better than the wooden handle small brushes or the China black handle ones.You should be able to find the Forney brand where welding supplies are;I had a little trouble getting them locally but finally found a good source.I use them for cleaning all kinds of rusty or corroded metal parts(they also work good on cooling fins and spokes)and they are excellent as you can go hard with them to remove junk or soft and then they'll be good for polishing a bit.

Will look online, thanks for the tips.  The below wouldn't be possible without your help!


All that buildup on the exhaust valves is GONE!



The screwdriver worked really well.  Nice addition to my tool kit.  I used the berkabile 2+2, let it sit, chipped away with the screwdriver, then scrubbed with scotch brite.  I call it the grcamna special 





Next I'd like to further clean and polish that bowl the valves sit in (sorry for lack of terminology).  I'd also like to soak the entire head so I think removing the valves and valve springs is a good next step.  With the springs out and the valves freestanding, can I take the scotch brite to them for further polishing?  Can I soak them?  Or will these two damage the seats.  Can I also soak and scotch brite the valve seats on the cylinder head, or should I be carful not to touch them with scotch brite once the valves are out.  I will be lapping them at a later date.

[grcamna2]

Do you know anybody w/ a blasting cabinet?(soda blasting or heavier)so you can have them gently blast the entire head to clean up everything including the loose valves and valve seats.

[sbeckman7]

Next I'd like to further clean and polish that bowl the floats sit in (sorry for lack of terminology).

You mean the float bowls? 

[iiAtlas]

Do you know anybody w/ a blasting cabinet?(soda blasting or heavier)so you can have them gently blast the entire head to clean up everything including the loose valves and valve seats.

I can do soda!  I tried sans-cabinet last time and it was an absolute mess.  Maybe I'll pick one up and give it another go.  If not, is the scotch brite still an okay idea?

Next I'd like to further clean and polish that bowl the valves sit in (sorry for lack of terminology).

You mean the float bowls? 

Hah!  Thats exactly what I DIDN'T want to type!  Corrected above...

[grcamna2]

Do you know anybody w/ a blasting cabinet?(soda blasting or heavier)so you can have them gently blast the entire head to clean up everything including the loose valves and valve seats.

I can do soda!  I tried sans-cabinet last time and it was an absolute mess.  Maybe I'll pick one up and give it another go.  If not, is the scotch brite still an okay idea?

Next I'd like to further clean and polish that bowl the valves sit in (sorry for lack of terminology).

You mean the float bowls? 

Hah!  Thats exactly what I DIDN'T want to type!  Corrected above...

I would use the services of a sand blasting cabinet especially inside the exhaust ports,many places have them,if you know a friend or craftsman who has a blasting cabinet w/ medium grit(or glass beads) material or Vapor Blasting it will make short work of all that;if the sand,etc./media is too abrasive it's not good but an experienced hand at the controls of the blaster:holding the outlet of the blaster far from the valve seats will soften the effect of it and will quickly clean the ports,etc.,of course fine glass beads is great.
I would be careful w/ using any scotchbrite on the actual valve stems especially where the valves move up and down inside the guides:go very lightly w/ grey scotchbrite if at all in that area.I think you can slowly & carefully chip away at the valve seats in the head and on the valves if you don't have access to a blast cabinet.A fine brush quickly on a power wire wheel on the valve seats themselves will clean them up in no time.I took my head to a shop who has a blast cabinet and was careful and it was cheap.

[calj737]

If you use a blast cabinet, fine glass is my recommendation, and NOT aluminum oxide.

[iiAtlas]

I would use the services of a sand blasting cabinet especially inside the exhaust ports,many places have them,if you know a friend or craftsman who has a blasting cabinet w/ medium grit(or glass beads) material or Vapor Blasting it will make short work of all that;if the sand,etc./media is too abrasive it's not good but an experienced hand at the controls of the blaster:holding the outlet of the blaster far from the valve seats will soften the effect of it and will quickly clean the ports,etc.,of course fine glass beads is great.
I would be careful w/ using any scotchbrite on the actual valve stems especially where the valves move up and down inside the guides:go very lightly w/ grey scotchbrite if at all in that area.I think you can slowly & carefully chip away at the valve seats in the head and on the valves if you don't have access to a blast cabinet.A fine brush quickly on a power wire wheel on the valve seats themselves will clean them up in no time.I took my head to a shop who has a blast cabinet and was careful and it was cheap.

If you use a blast cabinet, fine glass is my recommendation, and NOT aluminum oxide.

Very hard to find those kinds of people here in NYC.  I think my only option really is doing the blasting myself (with soda) or getting at it with scotch brite.  I will remove the valves and valve springs later today then soak the entire block in a solution of aircraft cleaner and water.  Then I'll be able to tell how far off I am and how much harder I need to clean. 

[sbeckman7]

Sounds like a good plan.  Yes NYC isn't exactly the city of machinists    But probably somewhere close like Newark.  Also, the actual "bowls" you are referring to are known as the combustion chamber

[iiAtlas]

Sounds like a good plan.  Yes NYC isn't exactly the city of machinists    But probably somewhere close like Newark.  Also, the actual "bowls" you are referring to are known as the combustion chamber

Good to know!  Thanks.  I have all the machines for the most part so I like to give this kind of stuff a try myself, when I can.