Topic: Marissa's 1972 CB500

[DaveBarbier]

I don’t see why you think the engine is dead.

First, remind me what you did for the rebuild. Was this re-ringed and bored or honed? Is this the first oil change since the rebuild?

You might want to cut open your oil filter and see what you find in there. Don’t grind or saw it open because you’ll introduce metal flakes. Puncture and cut it open.

Do you have electric start on this?

[Marissa]

I don’t see why you think the engine is dead.

First, remind me what you did for the rebuild. Was this re-ringed and bored or honed? Is this the first oil change since the rebuild?

You might want to cut open your oil filter and see what you find in there. Don’t grind or saw it open because you’ll introduce metal flakes. Puncture and cut it open.

Do you have electric start on this?

Reringed, and honed. First oil change.

Electric start is on. I don't think I have good legs to kick it over with, as when I kick over the bike I can never get it to start like that. This has always been the case. CB500, Cb550, never got any engine to start with a kick with these legs. I don't know if it's me or if I didn't set up the kickstarter well enough, and the Cb500 engine, was well... a basket case, so who really knows why that one didn't work well either.

When I tried starting it today, it spun over very fast. Compression did not sound like it there anymore. I no longer hear the compression "whoosh" but just the turning of the crank and the starter.

[DaveBarbier]

I don’t see why you think the engine is dead.

First, remind me what you did for the rebuild. Was this re-ringed and bored or honed? Is this the first oil change since the rebuild?

You might want to cut open your oil filter and see what you find in there. Don’t grind or saw it open because you’ll introduce metal flakes. Puncture and cut it open.

Do you have electric start on this?

Reringed, and honed. First oil change.

Electric start is on. I don't think I have good legs to kick it over with, as when I kick over the bike I can never get it to start like that. This has always been the case. CB500, Cb550, never got any engine to start with a kick with these legs. I don't know if it's me or if I didn't set up the kickstarter well enough, and the Cb500 engine, was well... a basket case, so who really knows why that one didn't work well either.

When I tried starting it today, it spun over very fast. Compression did not sound like it there anymore. I no longer hear the compression "whoosh" but just the turning of the crank and the starter.

For the first oil change after a re-ringing you’re going to get metal and some sludge in the filter and oil pan. I don’t know if that’s excessive, but sludge is normal.

Ok, just checking how you’re starting it. Your kicker is probably fine, it’s more likely that you’re minute.

Do a compression check and report back. If you’re low, add some oil to the cylinders and see if it improves. If you suspect the cam bearings are bad you can remove the valve cover and have a look at the cam.

Are you suspecting the oil thinning out with gas as the cause of low compression? (I’m not conceding that you actually do yet) Because I don’t follow that.

[Marissa]

Compression test results;

1- 30psi
2- 35psi
3- 33psi
4- 31psi

I’m not sure how accurate these readings are because it was done with a harbor freight tester which has roughly 3 feet of hosing on it. I cleaned out the oil pump, checked for scoring and there’s not much on the rotor inside, and it’s still plenty in spec in both the OD and ID. When I was checking for compression tonight I saw the oil light turn off so we have pressure again. Regardless, I ordered a Marshall oil pressure gauge and I will install it to confirm pressure.

I ordered a borescope and I think I will order a leak down tester as well. I took off the valve cover and the cam actually looks okay. It is definitely polished at the contact points at the lobes- but I sort of expect them to still be in spec. I will likely measure them anyways. Cam chain is tight and seems in spec.

Perhaps I can fix this faster than I thought, depending on how salvageable it is. Will post more pictures soon.

Thank you to everyone who messaged me with support. My dad says I owe it to myself, and all of those around me to finish it. So I will continue bit by bit.

[jgger]

Marissa, you are the envy of many on this forum for your persistence on this project,  you have put many guys to shame! That being said now take a deep breath and dont freak out.

1.  Honda made these motors brutally durable.
2.  You have done alot with this bike, but I doubt you killed it.
3.  IIRC awhile back were you having clutch issues?
              Could be the source of some sludge.
4.  You had a boat load of bad fuel which combined with the float level also could lead to sludge.
5.  3 ft of hose on the compression tester will yield low readings.
               So will a closed throttle and/or closed choke during the test.
6.  A fresh (as in rings not seated) bore will also be a tad lower.
7.   The first and maybe even the 2nd and 3rd oil change will have glitter in it.
8.   Alot of that crap in the pan could be from excess sealer that has washed free.

I don't think you have an issue to worry about.  Your eye for detail and your quest for perfection are taking you places you don't need to go.

Soooooo, if the float level is sorted, change the oil and filter and enjoy the fruit of your labor.

Go Girl!👍

I forgot, your Dad is a wise man, take his advise!

[DaveBarbier]

Marissa, you are the envy of many on this forum for your persistence on this project,  you have put many guys to shame! That being said now take a deep breath and dont freak out.

1.  Honda made these motors brutally durable.
2.  You have done alot with this bike, but I doubt you killed it.
3.  IIRC awhile back were you having clutch issues?
              Could be the source of some sludge.
4.  You had a boat load of bad fuel which combined with the float level also could lead to sludge.
5.  3 ft of hose on the compression tester will yield low readings.
               So will a closed throttle and/or closed choke during the test.
6.  A fresh (as in rings not seated) bore will also be a tad lower.
7.   The first and maybe even the 2nd and 3rd oil change will have glitter in it.
8.   Alot of that crap in the pan could be from excess sealer that has washed free.

I don't think you have an issue to worry about.  Your eye for detail and your quest for perfection are taking you places you don't need to go.

Soooooo, if the float level is sorted, change the oil and filter and enjoy the fruit of your labor.

Go Girl!

I forgot, your Dad is a wise man, take his advise!

Totally agree

[Marks78]

^^^^ Well put, well said!!  Not only are you an inspiration and the envy of many on this forum but to others as well.  I have a 17 year old daughter who is inspired by all you have accomplished and continue to accomplish. She doesn't ride, yet, but I share your journey with her and it is meaningful to her.
So, take that deep breath and down the road you go one step at a time.  And thanks for sharing!   

[Marissa]

2.  You have done alot with this bike, but I doubt you killed it.
3.  IIRC awhile back were you having clutch issues?
              Could be the source of some sludge.
4.  You had a boat load of bad fuel which combined with the float level also could lead to sludge.
5.  3 ft of hose on the compression tester will yield low readings.
               So will a closed throttle and/or closed choke during the test.
6.  A fresh (as in rings not seated) bore will also be a tad lower.
7.   The first and maybe even the 2nd and 3rd oil change will have glitter in it.
8.   Alot of that crap in the pan could be from excess sealer that has washed free.

Yes, I had clutch issues in the past. At some point I accidentally put an extra clutch pack in so that would make sense. Also, I just remembered I used HondaLube, or whatever that Honda lubricant is that is high in Molybendum on the cam and rockers. (Which is grey and sludgy)

And yeah, last night I totally forgot to open the choke and throttle for testing.

Here's pictures and videos of what's going on:



This definitely looks like a mix of oil, Hondalube, and a little dust.





The left bank has the worst scoring, but realistically visually I don't think that really looks bad.

The contact areas on the lobes look a little broken in, but again, no scoring. Valve lash was adjusted back in November, and I checked in March I believe.

"

[jgger]

See, there ya go! Now get that puppy on the road.👌

[calj737]

Are the spark plugs removed while you're cranking? If so, the crank speed will always sound faster as there is little to no compression being created.

[DaveBarbier]

I laughed out loud at the “Ahhhh...yeeeaaahh!”

[flatlander]

LOL yes that was classic 
big relief! so now that it's all good fire that thing up, we all want to hear it run!

[Marissa]

Are the spark plugs removed while you're cranking? If so, the crank speed will always sound faster as there is little to no compression being created.

No, spark plugs are in. That's why I'm concerned there's still something not right.

[DaveBarbier]

Do you feel compression at all if you slowly use the kicker?

Is anything keeping you from firing it up?

[Marissa]

Do you feel compression at all if you slowly use the kicker?

Is anything keeping you from firing it up?

I feel tension in the kicker when it gets to the T1-4 indicator on the crank. I think also at the 2-3 but not as much as 1-4. But I think that's considered normal/common. However, it's definitely not as much as it used to be.

I haven't put it back together yet because I've been working on some branding for freelance work since I got home. I have Thursday off though so I will assemble it that day and see what happens.

I wanted to wait for my borescope to come in before I try anything further, but since everyone here is pretty confident in it, I guess I'll give it a shot anyways. I think I'll want to grab compression numbers again though but with oil added to the chambers and obviously to make sure I keep throttle and choke open.

[jgger]

Do 2 tests on the compression. Do it dry first, then do a wet test. That will isolate the rings if the 2 numbers are way different.

If you are turning it over without the rockers in place then all the valves are closed, no air in and no air out.  It would feel like low compression. I only say that because you said you still have to put it back together.

[calj737]

In many cases, a lack of compression on a newly rebuilt motor tends to be the valves adjusted incorrectly.

While the cover is off, go back and check that they were set while in the correct stroke per cylinder. It is easy to get that wrong.

[flatlander]

the cover needs to go back on to check valve adjustment, it's a 500 not 750

[jgger]

That's what I was eluding to above. Turning the motor over without  the cover/rockers will not feel or sound normal. I hope it will be that easy.

Marissa we are all pulling for you, you're so close don't give up now.

[Marissa]

Compression numbers were taken with valve cover on and spark plugs in the rest of the chambers.

Got my borescope in the mail, and aside from some little scoring marks, everything looks fine. I scraped the dirty gunk on the tops of the cylinders with the borescope end and it's all residue/not damage so I'm not really concerned.

I think next step is leak down test.

Valve lash was adjusted back in November, and rechecked around March I believe. I'll recheck it but it was pretty straightforward to me. There's a good thread on it somewhere that I followed.









Those pictures are in order 1-4 and they are the best pictures I can get with the angle of the spark plug hole and the borescope.

Got a cool Marshall gauge, think I will mount it on the right side and connect it to the oil galley by the ignition.

[DaveBarbier]

I don’t want you to get too paranoid and fixated on the compression. Honestly it all looks ok and on a new motor when the rings haven’t been full seated you might get a false positive when you do a leak down. If I were you, I’d ride the hell out of it for a few hundred miles and then see if any problems arise. As said above, these motors are built like a brick #$%* house.

[Cb750 Racer]

I don’t want you to get too paranoid and fixated on the compression. Honestly it all looks ok and on a new motor when the rings haven’t been full seated you might get a false positive when you do a leak down. If I were you, I’d ride the hell out of it for a few hundred miles and then see if any problems arise. As said above, these motors are built like a brick #$%* house.

+1

[Marissa]

I can't get it to really start back up.

I got it to hiccup with starter fluid, then, out of curiosity I decided to put the fuel valve on "Reserve" and see if it would do anything. Throttle 3/4 open because that's been the only time starting it over has "felt" more confident I guess?

Instantly fired, high rpms, so I lowered throttle then it died. Maybe 3-5 seconds of running.

Popped the gas cap, rust in tank again, even with full tank of gas

I'm assuming this is clogging the fuel valve in some odd way. This is essentially the same exact problem I had about a month ago, only worse. So I'm simply tired of it and I'm going to buy the Caswell Gas Tank kit, likely in Battleship Grey or Dragons Blood Red so I can see it's been applied against metal. Also, I figured it can be used on the inside of the left side cover, to make wiping off grease much easier in that area. I remember that area being so gnarly on both the 500 and 550 engines.

Also noticed drops in carbs 2,3, & 4's drain tube. Which is silly because I just did a float level test. Is it possible that sometimes this happens when you open the fuel valve while it's on the kickstand?

I feel like I have no real direction to start and that I'm just going in circles.

PS: Please excuse the oil stained garage floor, aiming to tackle that once this bike can move under it's own power and I can pressure wash the floor, lol.



"

[jgger]

Marissa you are soooooo close! For what it's worth,  here is my take. (In list form, of course🥴)

1.  You will not be able to get it dialed in with bad fuel.....but you knew that.

2.  Do you have an auxiliary fuel tank/bottle you can use?  Do your final tuning with that so you know you are getting clean/fresh gas.

3.  Having to switch to reserve with a full tank of gas is not good. Either the petcock or the tank has issues that need to be addressed.  It sounds like you have it narrowed down to the tank.

4.  As for the overflows dribbling, that could be one of two things. If the carb bowls were empty (probably were) when you turned on the gas they could maybe leak a little if the bike was on the side stand and the floats just got hung up. Or it could be that the bad fuel left some crud in the seats. You might be able to open the drains and run some clean fuel through to flush them clean. Also is there sediment in the bowls?

5.  I have no experience with tank liner, but that won't stop me from giving you my opinion.  When you de-rust the tank, use a product that is designed for that like metal rescue, it may slow the flash rusting. No more vinegar,  you have seen that cheap can be expensive. Follow the instructions to the "T" for best results. Try to minimize the time between de-rusting and coating, that should help with the liner bonding to the tank. You have proven your patience  so let everything cure before use.

6.  Last, I am an old man with no bike that runs and it appears that life isn't going to allow me to have one anytime soon. So  humor this old guy as I live and ride vicariously through your project and get that puppy on the road.

Good luck, Jim

[wolf550]

that's how my drain tubes look also
I know its in there but never see it moving fuel anytime
so either its normal or we got the same problem

yeah do the water bottle trick with the fuel so you know its clean