Topic: Cam chain adjust spins round and round + glitter in the oil.... help? CB550 PICS

[Duanob]

When installing the camshaft/sprocket/chain follow the order shown here, it will save you a lot of frustration.

See Paragraph 12 and fig. 84.

When adjusting the cam sprocket timing, it has to be exact as shown in fig. 85. Not one tooth off. If it is you can loosen the sprocket bolts and cam chain tensioner and inchworm the chain around the sprocket by a tooth if necessary.

[DustyRags]

Thanks, Duanob! Yeah, I tend to go for the gusto. "Learn by doing" is the term, I think

Thanks for the tips! I've got that PDF printed out and practically memorized, and I'll be checklisting it as I go. I have a complete Vesrah gasket kit, which I've had two mechanics verify has everything I'll need. Rubber bands are on the list.

Paint- I actually had great luck with the automotive rustoleum (only the automotive) in the past, and I'm actually really curious how it'll last on a gas tank. The current plan is to leave the tank bare and add a single racing strip for now, so if it needs to come off, it should be fairly easy.

Also, I'm poor and don't have proper painting equipment. The bike cost me $500, and all the tools and materials so far are probably less than $300. Doing this on the cheap. 

Still, doing it right where I need to, and maybe I'll have the time and cash to do a full resto or mod build in the future. I'll post it here.

Keep chiming in with tips, please! If I don't know it, it's good to hear- if I do know it, it's good to be confirmed- and if I think otherwise, it's good to be challenged!

[JimS63]

Hey DustyRag, I just spotted your thread. VERY cool. I live just over the hill from you and am a fairly new rider myself (1977 CB750A). Maybe after your bike is done we can meet up and/or ride. I'd love to see the finish project! Jim

[DustyRags]

Hey Jim, love to go for a ride! I might (might!) get the build done today, but I rather severely doubt it- but sometime in the next few weeks, definitely! Ran into another guy who lives right across the street from where I'm doing the build who's also just building up his first bike a '76 750. Apparently we need to get an east bay newbie ride together

Check back in a few, we got the tank stripped and painted yesterday- pics forthcoming in within the hour.

[DustyRags]

OK, really quick before I run off and start building this bastard!

First, Duanob, thanks for the note on the oil passages! I puffed some air-in-a-can through them, and sure enough- fwip, fwip!- out came two little bits of crud. Glad I found those! The rest were clean. Did the same to the cylinders, just in case.

Got the pipes cleaned up somewhat cleaner. They're still dirty, but no longer nearly as filthy as they were. Also inspected- look sound. Just gotta figure out how to get everything lined up so they don't blast out the crossovers anymore.

And then the tank! It started out mostly stripped, but looking pretty rough.



I hit it with a razor blade, but all the bits of paint that had been all beautifully soft from the Aircraft stripper had re-hardened. No good. Tried sand paper, but it fouled up super quick. Tried a cup brush in the drill- no good, too slow. So I stuck around and got the bits around the filler and the emblem bosses cleaned up with a razor blade while my brother ran out to get a brush wheel for the angle grinder. Fifteen minutes later, it was clean.

Then I wet sanded it with 320 grit to get all the scuffs going in the same direction.



Then I wiped it down with paper towels, blew air-in-a-can behind the emblems and any other nooks and crannies to dry them out, wiped the whole thing down with acetone and taped it off. I eyeballed a stripe down the center, matching up with a conveniently just-visible welding seam, and taped off the right side of the tank right to the edge. I left the bottom open and sprayed it. There were some points where the old paint had come off where I got some stripper on it, and a few very small rust spots. Got that all prepped as well. Then I measured out 1.5 inches and laid a second tape line just to the left of the center line. Taped the left side of the tank, and cleaned up the edge with a razor blade.

Two layers of rustoleum automotive grade primer, and then three of paint. The first two were thin covering layers, the third was nice and thick and flowed very well. Here it is taped and painted.



Finally I unpacked it, examined the lines (beautiful!), gave it a quick wipe down with mineral spirits and paste waxed the hell out of it. After some polishing I popped the emblems* on, and boom! Brushed steel tank with a racing stripe!



And now if you'll excuse me, it's time to buy more nitrile gloves (we were through 100 gloves in the last box alone, and had probably 30 left in the box before that!), and go start building!

*Funny story- the emblem I bought had two of the little locking clips on it, but I lost one. The second emblem didn't have any, so I'd pretty much resigned myself to just gluing them on- but when I scraped the last of the paint out of the brackets, I found three clips buried in there! So now I had four, and the emblems clicked right in.

[DustyRags]

More progress! I got a lot done this weekend! First step: clean. Clean more. I made sure every hole and orifice in the cylinders was clean, clean, clean. Wiped the cylinders with oil, inside and out, and installed the base o-rings. Then we lined up the gaps in the piston rings, cleaned the rings again, lined the gaps up again, wiped down the crank case surface (repeat for a while) and got the pistons up on blocks of wood.

Here it is, all ready to go.



The blocks of wood turned out to be more trouble than they were worth, so they got chucked. Right about this point, my folks came in from out of town, my brother took off to go get some sort of fancy cheese for dinner, and my pops jumped in with an extra pair of hands to get the pistons in.

With plenty of oil and some careful shimmying, we got the rings in with no problem. The key is to get them all lined up, and then carefully press it down. Easy enough with four hands, but it would have been a nightmare and a half with just two. For that, I would definitely want to have ring compressors.

Then we got the front chain guide placed, and the rear one bolted in place. This gave us some consternation- there seemed to be some sort of high spot that was preventing the cylinders from sitting flat. Eventually we figured out that the chain tensioner was somehow pressing against it and preventing it from lying flat. Or, more to the point, it would lie flat and then jump back up. Once we backed the bottom nut off, it was fine. We tapped it down and moved on.



The head went on without a hitch. Easy-peasy, just slid right into place. And then the torquing. Oh man, the torquing. There's a lot of argument about the best and most reliable way to torque, and whether to use gasket sealer and whether not to, and how often to torque it, and whether to use o-ring glue and and and...

I asked Charlie from Charlie's place. He said no gasket sealer, just a touch of oil on all the rubber, and then torque the bolts to 17 ft-lbs. Torque them in the proper pattern, torque them two lbs over (19 ft-lbs), back it off to 5 lbs, and then re-torque it to 17 ft-lbs, going in small increments the whole way. My torque wrench (0-75 ft-lbs, dial-style) is in 2.5 lb increments, so that's what I used. Wasn't tough at all (pay attention to get the sequence right!), and we'll see how it holds up.



And there it sits for now. Once again, wrapped up like a piece of meat in the butcher shop with plastic wrap all around the open holes, waiting for me to come back later this week and finish it. Still needs the cam installed and adjusted, the head cover and the tappets tuned, the breather cover, the carbs installed and hooked up to the air box, and all the various cables and hoses plugged back in. Then it should be just a matter of new oil, kick it over a few times to get it all properly lubed, pour some gas and let it roar. It's so close I can smell it!

[Hush]

Impressive, you are doing a really great job of that bike.

[Frostyboy]

It's great to hear that it's on the way back together, but I did shudder a bit when I read this :

..... Then we lined up the gaps in the piston rings, cleaned the rings again, lined the gaps up again, ....

I think it's just the way you expressed it, but you did stagger the gaps didn't you? 

[dave500]

absolutely its going great,make sure the bottom of the tentioner goes into its little well,it can be fitted wrongly so easily,if its wrong itll look like this,you can remove the pan and look to make sure or before you had the head on you can feel the top of the tentioner and rotate the engine and feel if the primary drive hub is rubbing on it,youll end up with a rattly chain that wont adjust.


yeah well spotted frosty,we hope the gaps are staggered.,,it looks wrong although i cant tell exactly but what way is that little forward chain guide installed?its rubbing face should be facing the front and it sits inside the loop of chain pushing out not on the outside pushing in like the main one does!it has "UP" written on it aswell.

[Frostyboy]

Hey Dusty, I hate to have to tell you this, but I think you have the front chain guide in backwards & the chain on the wrong side.

[Edit] Dave just beat me to it.

[DustyRags]

Oh, &^%$&^%^& you're all right. That front chain guide is in backwards. So glad you caught that!

NEVER build hungry and impatient. A rule I forgot. And it seemed to be going so well.

Dave- thanks for the mention of the well the tensioner goes in, I had no idea that was there- that's probably what was causing the issue.

Frosty- yes, lined up in the sense of "in the correct place"- they're 120 degrees apart. That part I got right.

So for all of you a question- now that it's been torqued, are those seals trash? If I unstack it all again, will I need new seals, or can I use these again? Considering it's been torqued, but has NOT been turned over or fired up.

[TwoTired]

Compression gaskets (as in; they are squeezed to make a seal and are composite paper based or fibrous) generally survive one compression cycle reliably.  As there was no heat added while under compression, perhaps they didn't compress so much as to survive and be effective for a second compression cycle, and won't stick to the metal surface upon dissassembly .  But, it is a risk.  If you want to insure against leaks, replace them.  If you are a gambler then try them again.
  Your fibrous gaskets are now "used" and I will sometimes reuse a gasket, but, only with some Gaskacinch on one side, assuming the gasket comes out completely intact, without leaving some of itself on the metal surface.

Rubber bits like oring material can be reused as long as they remain soft and resilient.

You'll note the head gasket has a metal ring around each cylinder.  These are not resilient and do not spring back.  They still conform to the micro fissures in the metal intended to seal as the head bolts are brought to tension.    Putting them back in exactly the same place is risky.  And, to make a new conformal seal they need to be torqued to a higher value than last time.
Perhaps just a little more torque will allow it it do proper service, Couple pounds.  However, with over torquing, comes the risk of pulling the studs out of the aluminum block.

BTW, never over torque and then re-torque to a lower value, at least not with a compression deforming type seal.

The gaskets behave like modeling clay you squeeze and they conform release pressure and you have a gap between the clay and whatever was doing the compression.

There is a little wiggle room with the Honda engine studs as they are actually stretching some and behaving a like very strong springs.  They are still way stiffer than the gasket material.

Your call.  Like to gamble?  If not replace with new.  I'd say, at least replace the head compression gasket.  Unless, you used a copper head gasket, if so anneal it and reuse.

Cheers,

[dave500]

ive used head gaskets twice over,not best practise,,if they come off with out deforming or tearing itll be ok in your case as its still fresh.

[DustyRags]

Cool beans, thanks guys! If I can pull it off carefully and re-cinch it to the proper tension, I'll give it a shot. Worst come to worst, I'll just put some new gaskets in there in a few weeks. At this point, not a huge amount of extra work versus just doing it now. But might be a lot cheaper. I'll keep you posted.

[Frostyboy]

You're pretty cool Dusty. I know a few blokes who would've thrown a real tantrum on hearing that the engine has to come back down. You show real spirit in learning your way around your new 'trade'.
Good on ya. 

[DustyRags]

Thanks! I stay cool by telling myself that if push comes to shove, I can just part the whole bastard out on eBay and make my money back 

Seriously, though, without the help of the forum I'd be so screwed. This last mistake alone would have done me in- I would have gone and buttoned it up as-is, kicked it over and wrecked it entirely. Here's to the hive mind!

[dave500]

just torque the head to 18ft pounds,,dont torque those two little 6 mm bolts fore and aft on the head,,dont include them in the tightening sequence,,just nip them down last of all,dont put much pressure on them,,once the engine has had three or four hot/cold cycles just check them and re nip strangling the spanner(wrench),yeah i think frosty(owen) said it all,this bike will repay you in performance for your work,it couldve been worse,,like the carbs and exhaust back on etc,,you caught it early!

[DustyRags]

OK, I was wondering about those two screws fore and aft. They're not in yet, but I figured it was something like that. Do you know why they're there at all?

[Mo]

Hey Dusty,

Looking good so far. I'm currently at the same spot you are with the top end. When you placed the pistons back in, did you notice some squeaking as the turned?

[DustyRags]

I did not, but I haven't turned it over yet. Did you oil the rings when they went in?

[Mo]

I can't say I did. I guess that would be my issue.

[DustyRags]

Try squirting some oil into the spark plug holes if you haven't yet put those in yet. See if that helps.

[dave500]

OK, I was wondering about those two screws fore and aft. They're not in yet, but I figured it was something like that. Do you know why they're there at all?

they just apply pressure at the ends there over the gasket to prevent oil leakage.

[DustyRags]

OK, that makes sense. I'll hand-crank them to a reasonable pressure. Thanks!

[DustyRags]

More progress! And it's seriously late again, but here's a rundown of the night's trials and tribulations.

It started with taking the head back down, 2.5 lbs at a go. Not much to report there- it went pretty quick. Then we snapped a strong magnet to the forceps to the snag the nuts out of the wells. Easy peasy, but the only way possible.



Next, we carefully peeled the head off without disturbing the head gasket, and shook the washers out. In the process, we also shook out the oil channel o-rings. Right! Forgot those were there. They went in the parts pan with the washers and nuts. Then somebody bumped the gasket (the guilty party shall remain unnamed, but suffice it to say they own the shop), so the gasket came out entirely to avoid damaging it.

Then the fun began. Raise the cylinders without disturbing the base gasket. OK, they don't want to go... OK, your side's high... now my side's high... we got it finagled up a bit, and the chain guide out and flipped around, but then couldn't get the tensioner seated right. In, out, up, down, finally got the tensioner seated and the cylinders down and went for the head gasket when we saw the guide sitting on the rag next to the engine.



We got the cylinders back up, the tensioner out, the guide in, the cylinders seated, the tensioner in, rotated the engine to make sure everything was working, and boom, we were golden! Head gasket on, OK, let's torque this bastard!

Luckily, my brother glanced into the parts pan, and noticed two black little O's standing out from the white lacquer finish. That pretty well earned him a forgiveness for the gasket screwup earlier, so we carefully raised the head again, inserted the o-rings, and put it back down. Then in with the washers, the nuts, drop one, fish it out, get one crooked, swear a lot, finally got them all situated, hand tightened, and finally torqued to 17.5 ft-lbs of pressure. I'll come back and back them off a bit and torque them back up to spec next time I attack this beast.

My brother rigged a proper surgical illumination so so we could see the patient and the torque wrench values.



Next I tried to find the torque values for the headers in the manual, but no dice.



We went at it without torque values, and got the right exhaust hung.



We found a Heineken in the recycling bins out back. Not sure who drinks Heineken around here, but it reminded me of my dad who has a soft spot for Heineken (although we've taught him to drink decent beer, for the most part). A pair of tin snips...



And boom! A custom made exhaust crossover! 4 minutes and 25 cents is a hell of a lot cheaper than a week and $17 (each) ordering them from Honda.



The left side didn't go nearly as smoothly. Looks like the left exhaust hanger was bent, and the pipes weren't lining up correctly. You can also see the left passenger footpeg sloping out. The right driver peg is sloping in a bit, but I'm OK with that, and it isn't nearly as bad as it looks in this picture. You can see the half-finished crossover dangling off the left exhaust as well.



We yanked the exhaust back up, and attacked the exhaust hanger with vigor and some very large pliers. By the time we were done it was tolerably straight, but the fat washer thingy inside the hanger had shifted a bit and we couldn't get the bolt through. My brother's a bit of a tyro, so he got the bolt threaded as far as it would go and then slammed it the rest of the way through with a framing hammer. Crude, but effective- the hole was clean and the bolt, surprisingly, wasn't damaged.

Both exhausts hung. Something about this picture just works.



The left footpeg still slopes out a bit, but I think the footpeg itself is just a bit loose. The kickstand is a bit wobbly too- some washers out to fix that, but I don't think it's an issue at the moment.

All straightened out, with both crossovers in place.



And there we sit for now. Next step is to get all those bolts backed off a smidge and re-torqued, then the cam and chain, head cover, tappet adjustments, breather cover, carbs, hoses, cables, tank, gas, go.