Author Topic: From Sh*tty to Shiny: Sbeckman7's CB350F Cafe Resto (Read 65679 times)

sbeckman7 · « **Reply #50 on:** February 01, 2016, 05:12:03 PM »

Got it. I don't think it will be a problem like you guys said, just have to do a little more hunting around I guess! I will probably have the frame blasted, so now it comes down to finding the shop that can blast the frame, let me go over it with the scotchbrite, and then PC it for under $250 total. So far I've spoken with West Coast Powder Coating (South San Francisco, CA), Melrose Metal Finishing (Oakland, CA), and Myers Sandblasting (East Oakland). Going to make a few more calls tomorrow and hopefully narrow it down. I'd love to have the frame sent out by the end of the week.

grcamna2 · « **Reply #51 on:** February 01, 2016, 05:23:14 PM »

Possibly look for a PC shop in a smaller town that you would have to drive a bit to get to..,more $ for fuel..
Try to get a fair quote for all the parts you want done in one shot;I ended up paying much more for all the little 'extra' parts later on.

sbeckman7 · « **Reply #52 on:** February 01, 2016, 06:16:43 PM »

Good to know. Fortunately I should be able to use the powder coating gun and over at the local community college. I'm taking a paint class just for this project

grcamna2 · « **Reply #53 on:** February 01, 2016, 08:46:15 PM »

I'd like to get some time in on that craft also,it would sure beat 'rattle can'

iiAtlas · « **Reply #54 on:** February 02, 2016, 07:10:32 AM »

Quote from: calj737 on February 01, 2016, 04:45:35 PM

Ah, gotcha. Use ScotchBrite pads. It will leave a directional scuff if you keep your motion consistent. Red or Grey should be perfect.

I can confirm this! Though accidentally...used ScotchBrite green on one of the float bowls and I have a nice brushed look which I wasn't exactly going for....

calj737 · « **Reply #55 on:** February 02, 2016, 07:26:42 AM »

Green is the most coarse, then Red, then Grey. Maybe start with Red to even it out, then follow with Grey to smooth it out.

iiAtlas · « **Reply #56 on:** February 02, 2016, 07:30:44 AM »

Quote from: calj737 on February 02, 2016, 07:26:42 AM

Green is the most coarse, then Red, then Grey. Maybe start with Red to even it out, then follow with Grey to smooth it out.

D'oh! I thought the opposite. Here is how it came out.

Oddly enough when I was putting the carbs back together yesterday I didn't even notice it. I have a feeling the effect has started to dull. I'm confident I could get the scratches out if I continued cleaning, but I don't want a "polished" look. Anyways...problems for another time. If you're going for a brushed look sbeckman ScotchBrite will get you there!

sbeckman7 · « **Reply #57 on:** February 02, 2016, 09:28:22 AM »

Good to know. And ironically, you have given me an idea for what could be a nice on my bike w/ brushed frame.. matching float bowls!

Some exciting news on the engine: I will be receiving the built head I mentioned earlier! It's a ported 350F head w/ lapped 400F valves and ground seats. Also significantly cheaper than the Time-sert thread repair kit

calj737 · « **Reply #58 on:** February 02, 2016, 09:37:39 AM »

sbeckman7 · « **Reply #59 on:** February 02, 2016, 12:02:13 PM »

Alright guys, called a few more places and narrowed it down to 3 choices. Two of them (Melrose and Champion Powder Coating) have top reviews, can blast and PC clear for ~250, and are happy to let me brush the frame with scotchbrite between the processes. The third one (Leon's) said they would do everything for ~175 but they have 3 stars worth of mixed reviews. I'm thinking for this reason, I will go with either Melrose or Champion. I am on a tight budget (self-inflicted) but I want to only do this once and do it right. Clear powder coat probably shows blemishes more than a painted color! Hoping to drop the frame off somewhere tomorrow

In other news, my Carb isolators and clamps arrived today from Japan and they look good! $30 well spent.

sbeckman7 · « **Reply #60 on:** February 02, 2016, 02:34:24 PM »

Ow ow!! Look at this beauty

Starting from the top down. Looks good so far:

Then the head came off. I think it could have been worse, but there was definitely sitting water in this thing:

The cam lobe journals had a good amount of wear it seemed. Is this normal for a bike with 24k miles or does it suggest an oiling problem?

They're just so cute

But jeez talk about room for boring!! This block could have been a good 2" narrower if it was purpose cast. Oh well, scaled production architecture does that...

The bores looked good as I rotated the assembly a few times. Definitely some cleaning to do though. Should I pull it apart even more?

And lastly, the reason this all started: looks like the stripped thread didn't go all the way, but it only has ⅓ of the grip length it used to have.

So, oh wise community, what next? Do I need to go further? I want to clean it up a bit (exterior as well as pistons and sealing surfaces) but I'm assuming it's best to do the outside with the engine either fully disassembled or fully assembled. Any advice?

Thanks as always!

grcamna2 · « **Reply #61 on:** February 02, 2016, 03:06:01 PM »

You could tighten the top-end back down and seal up all the ports,etc. and take it to a spot that has a high pressure water supply and then get you a thick bristle brush to get between the fins and spend a good hr. de-gunking it w/ some strong(foamy) engine cleaner,hopefully in a warm place.. then disassemble it;as far as the head goes,was it you that said you have a contact who's selling you a rebuilt cylinder head?

calj737 · « **Reply #62 on:** February 02, 2016, 03:07:17 PM »

My opinion is to remove the piston and ring and at least re-home the cylinders. With that standing water history, now is the time to discover and correct and problems in the bore.

sbeckman7 · « **Reply #63 on:** February 02, 2016, 03:10:43 PM »

Quote from: grcamna2 on February 02, 2016, 03:06:01 PM

You could tighten the top-end back down and seal up all the ports,etc. and take it to a spot that has a high pressure water supply and then get you a thick bristle brush to get between the fins and spend a good hr. de-gunking it w/ some strong(foamy) engine cleaner,hopefully in a warm place.. then disassemble it;as far as the head goes,was it you that said you have a contact who's selling you a rebuilt cylinder head?

Do you think some plastic caps will sufficiently seal the ports? That's my only concern: blasting wanter inside the cylinders. But I have some wire brushes and degreaser so maybe its time for a nice bath

I am indeed the one who will be (confirmed now) purchasing a rebuilt cylinder head from Old Scrambler.

Quote from: calj737 on February 02, 2016, 03:07:17 PM

My opinion is to remove the piston and ring and at least re-home the cylinders. With that standing water history, now is the time to discover and correct and problems in the bore.

Can I re-hone the bores myself using a kit from an auto store, or do I need to take it somewhere to have that done? Have some experience with hooning, but never honed before!

After that would a stock size ring kit be the way to go?

And also am I supposed to be able to just pull the cylinders right off now or are there some hidden bolts in the bottom end keeping it together?

calj737 · « **Reply #64 on:** February 02, 2016, 03:14:33 PM »

Many folks hone their own blocks using a Flex Hone stone. Ring changes are only necessitated if the bore diameter has changed. That can only be accurately determined with micrometers. You could remove the block and carry it to a shop and have them measure the bores and pistons to determine if a re-bore is needed.

sbeckman7 · « **Reply #65 on:** February 02, 2016, 03:27:08 PM »

Quote from: calj737 on February 02, 2016, 03:14:33 PM

Many folks hone their own blocks using a Flex Hone stone. Ring changes are only necessitated if the bore diameter has changed. That can only be accurately determined with micrometers. You could remove the block and carry it to a shop and have them measure the bores and pistons to determine if a re-bore is needed.

Ok. In your opinion, do you think that would be overkill on this little guy or a worthwhile expense?

grcamna2 · « **Reply #66 on:** February 02, 2016, 03:37:07 PM »

Quote from: sbeckman7 on February 02, 2016, 03:10:43 PM

Quote from: grcamna2 on February 02, 2016, 03:06:01 PM
You could tighten the top-end back down and seal up all the ports,etc. and take it to a spot that has a high pressure water supply and then get you a thick bristle brush to get between the fins and spend a good hr. de-gunking it w/ some strong(foamy) engine cleaner,hopefully in a warm place.. then disassemble it;as far as the head goes,was it you that said you have a contact who's selling you a rebuilt cylinder head?

Do you think some plastic caps will sufficiently seal the ports? That's my only concern: blasting wanter inside the cylinders. But I have some wire brushes and degreaser so maybe its time for a nice bath I am indeed the one who will be (confirmed now) purchasing a rebuilt cylinder head from Old Scrambler.

Quote from: calj737 on February 02, 2016, 03:07:17 PM
My opinion is to remove the piston and ring and at least re-home the cylinders. With that standing water history, now is the time to discover and correct and problems in the bore.

Can I re-hone the bores myself using a kit from an auto store, or do I need to take it somewhere to have that done? Have some experience with hooning, but never honed before!

After that would a stock size ring kit be the way to go?

And also am I supposed to be able to just pull the cylinders right off now or are there some hidden bolts in the bottom end keeping it together?

To the first question I would spray a bit of WD40 into each port and then,using a flat blade screwdriver stuff each port w/ a plastic bag tightly and seal-up all the other openings on the head and block to wash it,remove the bags later after you're done washing it and then finish disassembly w/ clean hands

Make sure to follow the advice to take the cylinders w/ each original piston in it's original bore/cylinder to the machine shop after cleaning those pistons up real good;keep each piston number to the hole it came out of.I would clean the cylinder bores from excess carbon too.

MoMo · « **Reply #67 on:** February 02, 2016, 07:50:31 PM »

A Flex Hone is the way to go, as it removes very little but yields a beautiful cross hatch pattern that will help the rings seat

sbeckman7 · « **Reply #68 on:** February 02, 2016, 10:18:09 PM »

Guys, I'd like to order the Flex-hone ASAP but not sure which option to select. I watched the video explaining to order the next largest bore-size if your exact bore isn't offered, so I know I need the 48mm version. I just don't know what material to select: Abrasive, Silicon Carbide, Aluminum Oxide, Boron Carbide, Tungsten Carbide, etc. What's the grit preference?Thanks for the advice!

I'll be sure to label each piston with its corresponding cylinder when I do so. I could start the cleaning tomorrow if I have time. Again just to clarify, the cylinders are supposed to lift off of the crankcase after removing the head bolts? Or am I missing something?

calj737 · « **Reply #69 on:** February 03, 2016, 03:36:00 AM »

The cylinders will lift up with careful and gentle persuasion. Restrict the cam chain from falling in the motor, and use the pry tabs on each side of the cylinders. If you can, soft wood shims wedged in between the block and lower case will prevent you from gouging up the aluminum.

It may well be quite difficult to get the bores to release if theres a stuck gasket on your block, and/or the bores have rust in them. I have found 2 things aide in removing the cylinders: heat applied directly at the seam (handheld propane torch) and rotating the crank while lifting. Squirt a bit of lubricant in the cylinders along the walls, and keep wiggling the bores up and away. As you get close to the piston slipping out the bottom, be prepared to catch it from whacking against the block. A second set of patient and careful hands is really helpful too.

MoMo · « **Reply #70 on:** February 03, 2016, 07:27:25 AM »

You'll most likely want to get 320 grit as it will be the least abrasive.

grcamna2 · « **Reply #71 on:** February 03, 2016, 07:42:04 AM »

A good,careful machine shop will measure the bores and see if they are still round also..

sbeckman7 · « **Reply #72 on:** February 03, 2016, 09:28:22 AM »

Thanks guys, I will order the 48mm 320 grit Silicon Carbide flex-hone today

Tonight I'll try my luck with removal of the cylinder head with my new torch!

iiAtlas · « **Reply #73 on:** February 03, 2016, 02:18:26 PM »

Quote from: sbeckman7 on February 02, 2016, 02:34:24 PM

Ow ow!! Look at this beauty

Starting from the top down. Looks good so far:

Then the head came off. I think it could have been worse, but there was definitely sitting water in this thing:

The cam lobe journals had a good amount of wear it seemed. Is this normal for a bike with 24k miles or does it suggest an oiling problem?

They're just so cute But jeez talk about room for boring!! This block could have been a good 2" narrower if it was purpose cast. Oh well, scaled production architecture does that...

The bores looked good as I rotated the assembly a few times. Definitely some cleaning to do though. Should I pull it apart even more?

And lastly, the reason this all started: looks like the stripped thread didn't go all the way, but it only has ⅓ of the grip length it used to have.

So, oh wise community, what next? Do I need to go further? I want to clean it up a bit (exterior as well as pistons and sealing surfaces) but I'm assuming it's best to do the outside with the engine either fully disassembled or fully assembled. Any advice?

Thanks as always!

Great writeup! This will be a big help when I crack my engine open. Looks like you're getting some great advice! I can advocate for the flex hone, works sweet!

sbeckman7 · « **Reply #74 on:** February 03, 2016, 03:03:57 PM »

Only advice I have to add is: make sure you remove the nuts from inside the little crevices of the engine head! I couldn't figure out why mine wasn't loose until I saw them, completely covered in about 40 years of gunk!

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Author Topic: From Sh*tty to Shiny: Sbeckman7's CB350F Cafe Resto (Read 65679 times)