Author Topic: Marissa's 1972 CB500 (Read 94318 times)

seanbarney41 · « **Reply #475 on:** July 13, 2019, 12:14:30 AM »

the bike is only firing on 1 or 2 cylinders...that is your problem, but how to get all four? usually it is because the carbs just are not right

double check, pilot jets and passages are clear (these are super tiny, especially on a cb550, takes virtually nothing to block them, even a drop of water), staic carb sync is good, float levels are good

and be confident enough to put the air box back on, otherwise you just don't have a chance in hell

seanbarney41 · « **Reply #476 on:** July 13, 2019, 12:17:56 AM »

everybody loves your project thread and is rooting fo ya and all that corny #$%*, but honestly, these are NOT simple machines. and you are close but this is where it gets down to the wire, and why I NEVER recommend for ANYONE to start riding with a vintage project bike

DaveBarbier · « **Reply #477 on:** July 13, 2019, 04:55:06 AM »

I know you’ve done this, but if I were there I’d adjust cam chain tension, check tappet clearance, check ignition (honestly I’m wondering if your not very popular electronic ignition is giving you problems), check plug gap. I would bet that your tank is actually fine and you moving to reserve then it starting was just a coincidence. That rust is not going to grow that much, flake off and clog the petcock. I have rust in my tank too. It’s not a problem when it’s minimal surface rust. Do you have clear fuel line or are you still using something opaque?

If you want, maybe I can come and take a look maybe next weekend?

Ignition question:
Do you have points you can install?
Can you take a picture of the what’s under the ignition cover?
Does this trigger module use the stock advancer? Or does it have a way to static time it? Like having a T - F - || marks for TDC, non advance fire and full advance fire?

Marissa · « **Reply #478 on:** July 13, 2019, 09:30:12 PM »

I pulled gas from the tank and it looked clean, so I ran it in the portable plastic tank. After 5 mins, it was clear that it was contaminated after some particles started to settle at the bottom.

So I'm glad I ordered that Caswell kit and I hope installation goes well.

I took apart the carbs again and there's even more crud in it now. It sort of looks like not all of the rust converter purged out. Which amazes me that it would get past the screen in the fuel valve, especially with the amount of shaking and washes I did. Regardless, I pulled all the jets and cleaned them in the Chem Dip I bought from Dave and that worked well. Tomorrow, I think I will aim to tackle removing the emulsion tubes for inspection and attempting to move the needles to the 2nd position where they seem to belong. I will also redo a float check. PS: Someone informed me we can get rubber tipped float needles? Sounded enticing considering the issues I have been having with mine.

From there, I may try starting it with new fuel in the plastic tank. I tried starting it today, all exhaust pipes were getting warm except #3, pulled the plug and it was not getting any gas. I also saw white smoke come out from the exhaust gasket for #1 so I'm thinking of replacing the copper gaskets and putting the steel exhaust mounts back on to eliminate any guessing.

Dave, I'm supposed to be going to Maine next weekend, perhaps the weekend of the 27th? And I guess it sort of depends on the progress I make before then. I'll keep you updated though, beer will be provided!

jgger · « **Reply #479 on:** July 13, 2019, 11:56:54 PM »

Marissa, are you using g a gas can to fill your tank? If it is a metal container that could be where the rust is comming from in your fuel. Just a thought. Also what percentage of ethanol is it? It isn't flex fuel is it?

DaveBarbier · « **Reply #480 on:** July 14, 2019, 04:21:24 AM »

Ok, I stand corrected. Your fuel does look contaminated with crap. Have you used your borescope to look inside the tank? Maybe there’s a heavy rust deposit that will take more time to remove.

And yeah, let me know what works for you. If you’re free when I’m free then it could work out. And I love beer, how’d you know!?

Marissa · « **Reply #481 on:** July 14, 2019, 07:01:38 PM »

Alright, so I pulled the carbs back apart today. I found my original emulsion tubes, dropped them in chem dip, and they came out great. I cleaned out all the pieces with chem dip and Q tips.

After seeing the smoke in the last vid, I decided to swap the steel exhaust mounts with new copper gaskets on to eliminate any "what ifs". As I was doing that, I was looking at my ignition coils and tracing the ignition wiring to each coil when I realized...

The coils were set to 1 & 3 and 2 & 4.

Such a small silly mistake with such a big impact!

So as stupid as a mistake this was, I was glad to find something that could easily be fixed and improve my chances of getting this thing where it needs to be.

While I absolutely hate working with fuel and have dreaded rebuilding these carbs again, admittedly it's become muscle memory and I was able to tackle them within 3 hours today with some motivation. I actually stopped by a vintage motorcycle shop yesterday looking for a quote to rebuild these, and instead of the guy trying to sell me on the job, he gave me some good advice and it inspired me to give it another go.

I finally took apart the needle housings and was able to successfully get all of those tiny M3 bolts free... Aside from either on carb #4. Those were so tough, the heads are messed up big time and unsalvageable. I think my best bet is to buy a used slide from someone someday. Anyways, so all my needles were set at the 4th clip from top, so I actually decided to leave those as is for now. With all 3 of the others taken apart, I was able to clean those up with chem dip all nice. The 3 slides that got taken apart were treated to new hardware also as a preventative.

With a cleaned out plastic test tank and new gas, believe it or not, not only did I get it to start up, but there's no gas in the drain tubes at all! And now, I'm firing on an extra cylinder!

The bike still needs like 1/4 throttle to start up, and needs to be held for like 30 seconds to stabilize enough for idle. But it's progress. I'm going to adjust my electronic ignition plate and likely advance it from where it is now. The problem is this system is very primitive so there's a lot of degree of adjustment.

I pulled the plugs off for a quick inspection, and 3 is still light. I'm curious if this is still a fuel delivery issue, as last time I pulled plugs, 3 was dry when all others were wet. And as I sit here typing this, I realized I never checked the T fittings to make sure those were clean, and I'm curious if the left side of the 3/4 T fitting (leading to 3) could be clogged (due to gravity and the bike leaning on kickstand?) I supposed perhaps I may have to adjust float height for that carb to be different than the others, but that would seem strange to me.

It's hard to see, but the bike was a little smokey. I'll have to see if it's like this again for next start up and see if there's leaks that need chasing.

1 and 2

3 and 4 (ignore the wetness on 4, that was from a valve cover leak leaking into the spark plug area, and it got covered when I pulled it out.)

HondaMan · « **Reply #482 on:** July 14, 2019, 07:36:10 PM »

Quote from: Marissa on July 14, 2019, 07:01:38 PM

Alright, so I pulled the carbs back apart today. I found my original emulsion tubes, dropped them in chem dip, and they came out great. I cleaned out all the pieces with chem dip and Q tips.

After seeing the smoke in the last vid, I decided to swap the steel exhaust mounts with new copper gaskets on to eliminate any "what ifs". As I was doing that, I was looking at my ignition coils and tracing the ignition wiring to each coil when I realized...

The coils were set to 1 & 3 and 2 & 4.

Such a small silly mistake with such a big impact!

So as stupid as a mistake this was, I was glad to find something that could easily be fixed and improve my chances of getting this thing where it needs to be.

While I absolutely hate working with fuel and have dreaded rebuilding these carbs again, admittedly it's become muscle memory and I was able to tackle them within 3 hours today with some motivation. I actually stopped by a vintage motorcycle shop yesterday looking for a quote to rebuild these, and instead of the guy trying to sell me on the job, he gave me some good advice and it inspired me to give it another go.

I finally took apart the needle housings and was able to successfully get all of those tiny M3 bolts free... Aside from either on carb #4. Those were so tough, the heads are messed up big time and unsalvageable. I think my best bet is to buy a used slide from someone someday. Anyways, so all my needles were set at the 4th clip from top, so I actually decided to leave those as is for now. With all 3 of the others taken apart, I was able to clean those up with chem dip all nice. The 3 slides that got taken apart were treated to new hardware also as a preventative.

With a cleaned out plastic test tank and new gas, believe it or not, not only did I get it to start up, but there's no gas in the drain tubes at all! And now, I'm firing on an extra cylinder!

The bike still needs like 1/4 throttle to start up, and needs to be held for like 30 seconds to stabilize enough for idle. But it's progress. I'm going to adjust my electronic ignition plate and likely advance it from where it is now. The problem is this system is very primitive so there's a lot of degree of adjustment.

I pulled the plugs off for a quick inspection, and 3 is still light. I'm curious if this is still a fuel delivery issue, as last time I pulled plugs, 3 was dry when all others were wet. And as I sit here typing this, I realized I never checked the T fittings to make sure those were clean, and I'm curious if the left side of the 3/4 T fitting (leading to 3) could be clogged (due to gravity and the bike leaning on kickstand?) I supposed perhaps I may have to adjust float height for that carb to be different than the others, but that would seem strange to me.

It's hard to see, but the bike was a little smokey. I'll have to see if it's like this again for next start up and see if there's leaks that need chasing.

1 and 2

3 and 4 (ignore the wetness on 4, that was from a valve cover leak leaking into the spark plug area, and it got covered when I pulled it out.)

NOW you're onto it!
With plugs that dark, it will smoke out the pipes and sputter. It appears the air bleed holes in those emulsifiers have been drilled out some? It could be the PO's attempt to get it to clean up, was commonly done in years past. If it went too far, then the needles need to be lifted a notch above normal to clean it up somewhat. But, that's for later, after you have all 4 firing again.

Boy, that is some nasty carb grit!

jgger · « **Reply #483 on:** July 14, 2019, 08:02:52 PM »

I am so happy for you. Sometimes we can't see the Forrest for the trees.

I just vicariously made a few hot laps around the neighborhood for you!🥳

You will be riding soon!

Cb750 Racer · « **Reply #484 on:** July 15, 2019, 12:05:46 PM »

I hope that fuel T I gave you got cleaned up before you threw it in. I almost cleaned it up but I figured if one was polished it would look a bit strange. Definitely needed a good cleaning I hope that's not the culprit. The carbs will constantly get clogged with sediment like that coming from the tank. Getting it lined may be the best solution. A fuel filter would stop all that but it's probably more of a challenge finding a fuel filter that can flow enough and still fit under your tank than just getting the crud out of your tank. You're in the right direction now, believe me your not far off from riding into the sunset.

Marissa · « **Reply #485 on:** July 15, 2019, 07:24:03 PM »

Quote from: Cb750 Racer on July 15, 2019, 12:05:46 PM

I hope that fuel T I gave you got cleaned up before you threw it in. I almost cleaned it up but I figured if one was polished it would look a bit strange. Definitely needed a good cleaning I hope that's not the culprit.

Justin, your T fitting you gave me went for carbs 1 & 2, so no worries haha. I did clean it when I first got it too!

Marissa · « **Reply #486 on:** July 17, 2019, 07:11:43 PM »

Does anyone have photos of the insides of their tanks before lining them? I followed the cleaning steps on Caswell's site (rinsing with water, acetone, letting dry etc.) and this seems to be how my tank flash rusts every time I clean it.

Is this what flash rust looks like to everyone? It's really textured and looks really sandy. I understand you are expected to line surface rusted tanks with Caswell (as I think they even say is expected) but to me I'm concerned this is too rough and gritty to hold the liner. I also tried getting pictures with my bore scope but it couldn't pick up much detail without more light so I just have iPhone pics.

Also, to be clear it's not totally dry yet, you can see it at the bottom, I'm waiting until at least tomorrow to make the call on whether or not I'm lining it.

Think I should just have this done by a shop?

I've read threads ranting and raving about Caswell, but none with photos, before or after lining.

jgger · « **Reply #487 on:** July 17, 2019, 09:41:34 PM »

To me the reddish brown is the flash rust. Think of shiney clean metal with a light coating of small brown spots.those dark brown/black areas are a much deeper rust. Which is probably the source of your problems.

What are you using to de-rust this time? Plus the more time between cleaning and coating the more the rust will grow.

Member DonR just danced the dance with a GL tank, maybe reach out to him for a good explanation. If that was my tank I would clean it more thoroughly before coating. Hopefully others will chime in.

onepieceatatime · « **Reply #488 on:** July 17, 2019, 09:52:03 PM »

I cleaned mine with a diluted acid (CLR type product) and a handful of drywall screws before I used Caswell. The rinsed with several flushes of clean water and a rinse of acetone. Once that was dry I used the Caswell. I would also probably clean your tank more, if it was mine, to get rid of the darker brown rust that is farther down in your tank first. the lighter rust near the top is more what mine looked like before sealing. I'll try to remember to take a picture inside the tank next time I get to my storage garage, as that is not one of the bikes I currently have registered.

RAFster122s · « **Reply #489 on:** July 17, 2019, 10:50:42 PM »

A forced air drying can help get the tank dry inside before you start the liner. Many will use a hairdryer to blow in the filler neck on no heat for several hours to dry out the tank.

Theoretically the acetone is to combine with the water, but this only happens when you do not have porous rust capturing the water.
I think you have more rusty scale to get out of the tank before you line it. I believe you would trap water in that rust and it would continue to rust beneath the liner until it eventually ate through the steel and began leaking. Often to help break the stuff free you will need to add a length of chain into your tank to provide a mechanical means of breaking it up. Filling with a liquid and your chain and then lots of agitation to break up the rusty scale.
Not using a chain that is so heavy it is going to dent up your tank but heavy enough to break up the rusty scale...yeah, I know not real specific on size.

My $0.02

David

DaveBarbier · « **Reply #490 on:** July 18, 2019, 02:16:57 AM »

Yeah, that’s not surface rust, that’s just rust. Flakey deep rust. You need to use an actual rust remover like Metal Rescue or the equivalent. First use water with screws or nuts and bolts or a chain and slosh the hell out of it. Just count the number of screws you put in so you know you got them all out.

calj737 · « **Reply #491 on:** July 18, 2019, 04:49:29 AM »

Stop using water. You’re defeating your intentions. Use MetalRescue or similar. This will leave a protective finish that will discourage rust. Then line it if you wish. You really only need to line a tank to resolve holes in the metal. Rust is easily treated and properly done, you should have no further occurrence.

Bankerdanny · « **Reply #492 on:** July 18, 2019, 09:53:33 AM »

Quote from: calj737 on July 18, 2019, 04:49:29 AM

Stop using water. You’re defeating your intentions. Use MetalRescue or similar. This will leave a protective finish that will discourage rust. Then line it if you wish. You really only need to line a tank to resolve holes in the metal. Rust is easily treated and properly done, you should have no further occurrence.

+1. The failure rate for liners is high. Not because the liner material itself is bad, but because prep is so important and even diligent owners can screw it up. If you don't have holes I just don't see that a liner of any brand is worth installing.

In 2011 I used a water/baking soda mix as a rinse/acid neutralizer post The Works toilet bowl cleaner treatment on my 550k then followed up with denatured alcohol to dry the tank and then Marvel Mystery Oil to coat and prevent flash rust. It worked well, and protected the tank for the couple days I needed before I added fuel.

I get why avoiding water is desirable, but a hose and high pressure water from a sprayer helps make sure all the loose rust get flushed out. The alcohol rinse immediately after helps dry the tank quickly to limit flash rust before the MMO can be applied to protect the surface.

SF · « **Reply #493 on:** July 18, 2019, 01:32:08 PM »

Plus 1 on metal rescue......fill it and let it sit while you work on the bike, giving it a shake and a turn every few days.

Sent from my iPhone using Tapatalk

HondaMan · « **Reply #494 on:** July 18, 2019, 08:19:59 PM »

If you'd like to do it once, and forever, and stop any 'almost leaking' seams, spring for the POR15 kit. You must remove the fuel petcock, then grease up 2 screws longer than the ones that mount it and screw them up into the petcock holes before lining: I recommend installing a small piece of roof flashing (or other similar thin sheet metal) with a piece of waxed paper between it and the tank, over the petcock's hole. Then do their 3-step kit and let it dry at least 2 days where it says, "let it dry well". This stuff makes a liner that is impervious to ANYTHING, about 0.060" thick, and it will make a little sealed housing over those extra-long screws you put into the petcock holes. Then when you pull them out, it leaves a sealed shroud over the tips of the screws that mount the petcock, further aiding in preventing future leaks. The kits are pricey, but IMHO worth every cent.

dave the welder · « **Reply #495 on:** July 19, 2019, 10:17:32 AM »

her is my 2cents worth on tank liners. I used Redcote? several years ago. followed direction to the letter. no problems ever. the only thing I noticed was the first tank or so the fuel had a slight red tinge. it did not hurt anything and was gone by 3rd tank. every one has there opinion on this stuff what ever you use follow directions EXACTLY as printed and life will be good

Godffery · « **Reply #496 on:** July 22, 2019, 07:59:46 AM »

+ 1 on the POR-15 product.
I build at least one er two custom Fuel Tanks a year and use there products exclusively for the sealing.

rb550four · « **Reply #497 on:** July 22, 2019, 12:47:53 PM »

Prep is key. I use the nuts and bolts method first every time, just because the bottom of the tank doesn't have flakey rust doesn't mean isn't happening on the inner top where the air is....like cast iron waste pipes, they rust out from the top where the air is ,not where the liquid lays. Have used toilet bowl cleaner or Evaporust does the job but the flash rust is a concern unless you use alcohol as a dryer. My favorite is gin with a little tonic and Tom Collins mix with a slice of lime, it make this dull job seem interesting, but the tank gets rubbing alcohol and when it's dry POR15. I don't like the tank mix because it's too thin and I feel that it needs a second coat ....the best part of the POR15 tank mix is that it comes in grey. The black POR 15 for frame restoration is what I like to use , seems to be thicker when dry if you leave too much in the bottom it can dry crackley. The only draw back on the black is that it's hard to see the fuel level inside.
It's a good product for battery trays as acid doesn't seem to effect it. The only thing that can wreck POR15 is sunlight it seems. So it's good in a dark tank . I never use it on MC frames because sunlight dulls out the gloss on my truck frames.

Godffery · « **Reply #498 on:** July 23, 2019, 02:21:49 AM »

I'll second that "Prep is key" statement, also not letting it puddle anywhere. (that apples to any brand coating you choose to go with)

DaveBarbier · « **Reply #499 on:** July 23, 2019, 04:44:20 AM »

With all this talk about liners, I still say to slosh the #$%* out of it* with water and nuts and bolts to remove the heavy rust and then metal rescue or similar after to remove the rest. Only line if there are pinhole leaks.

* I’ve heard of people putting the tank in the dryer wrapped in blankets with no heat with nuts/bolts or maybe a couple fist fulls of pennies so it’s less damaging. No liquid, rinse it out after the dryer.

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Author Topic: Marissa's 1972 CB500 (Read 94318 times)