Topic: Slowly - CB650 Custom 1980

[Azzarius]

Hi Everyone,

So just for the record, to all of you who said, "We told you so" ... I hate you  .

Now that's out of the way, I'm back at it.  Thank you for the hint that it can possibly be done on the frame.  I will try to do it that way as the engine removal proved to be a pain the first time around.  Just unsure that I will be able to remove the head that easily but I will see.  I had forgotten about the cam =-\, another fun part to remove.

So here is the plan.  I ordered a kit that contains just about every single seal and gasket there is in the engine, so I will replace them all with new ones.

Now the questions that I'm still not sure about based on your answers. 
-  Based on the pics on page 1 of this thread for the cylinder, should I hone the cylinder ?  Is that a it's better if you could.  Or is that you systematically need to do it ?

- Do I need to replace the piston rings ?

thnx for all of your inputs
Cheers

[CBJoe]

I think with all the work you are doing, it would be well worth to do whats been recommended in the past:

- Hone Cylinders
- Replace Rings - Make sure to check the specs (or have shop do it) for the cylinders.  If it's worn out of spec you will need the oversized rings if the cylinders need machined. This is unlikely if the cylinders haven't been damaged or machined before.
- lap the valves
- Replace seals

Shoot me a message if you have any trouble finding piston rings.  I think I have a new old set in storage along with a couple sets of CB650 Valves.

Cheers, Joe

[SOHC4 Cafe Racer Fan]

I think with all the work you are doing, it would be well worth to do whats been recommended in the past:

- Hone Cylinders
- Replace Rings - Make sure to check the specs (or have shop do it) for the cylinders.  If it's worn out of spec you will need the oversized rings if the cylinders need machined. This is unlikely if the cylinders haven't been damaged or machined before.
- lap the valves
- Replace seals

Shoot me a message if you have any trouble finding piston rings.  I think I have a new old set in storage along with a couple sets of CB650 Valves.

Cheers, Joe

That's a nice offer.  I had to hunt a little for my NOS 650 valves when I rebuilt my engine.

[rb550four]

Hi Az,
  I re read your thread, got to the part about 2 and 3  not getting hot....3 and 4....whatever, and switching coils ...no dif. switching cdi s... no dif..  Baffling right. So I was listening to the first fire video, and thought ...when he twisted the throttle the other 2 cylinders started firing, but started firing later... I think it's time to take those carbs apart for a real cleaning. I have had stubborn carbs  that  were just being impossible to get clean before even after a bath.
  I take all the brass and rubber parts out from top to bottom ,Leave all the cabs on the rack... do not take them all apart ,leave the linkage intact ( check the condition of the linkage between the carbs, clean and oil if needed).   Soak the brass in lacquer thinner in their respective bowls.
All the passages get drops of lacquer thinner too and a fierce go around or two with compressed air.... every hole must run clear before you put it back together. that is very important. If there are air screw adjustments on the bottom exterior towards the cylinders on your carb. count how  many turns to tighten the #2 carb, it's supposed to be factory set and all the other carbs are set to #2 in a vac sync , so this is important , you must know how many turns it takes to hit the bottom. I suspect PO had em out . I think they should all be in the 2 or 2 turn Plus range from bottom. be sure that these ( If you have them are clean and the passage is also cleaned ...don't be cheap with compressed air , be sure.
  Then it's time to sync those carbs. You can bench sync them first...people here like the drill bit method , that'll get you close, then go on to the vac syn and dial them in. I'm thinking this will make your life easier , and you'll have a better running machine . But that's what I would do after  the hone, re ring,valve work, seals and reassembly.But that's just me.

[Azzarius]

Hi Everyone,

Here am I, I've bought a full kit of gasket. I will go an replace them, but I still have questions wrt to the cylinder, the piston and piston rings. 

The cylinders
For the honing of the cylinder, I've read a good deal.  Some say I can do, some say I should to it, some say do not touch that and have it done by a professional shop.  My understanding of it is to create macroscopic threads that will hold oil on the piston wall(on the other side these creates imperfections that reduces the perfect seal thus reducing(slightly) the compression).  So the lazy question here, can I go without doing it ?

The rings
CBJoe mentioned that there are oversized rings(vs what I assume normal size rings).  Not sure exactly how what would that change, but  if I use oversized rings, the fit would be tighter --> better compression(if compression issue was to be due to bad ring fit).  Now since that, shouldn't we always be using oversized ring to ensure maximum/tighter fit?

The gaskets
Again, I've read about those, a lot a people complaining about just buying OEM, but it seems that OEM don't make them anymore for my bike, so I went with what I found.  I imagine that it cannot be worse than what I have now.

Gasket question.  Are gasket single use ?  What I mean is that if I put the news gasket in  and torque the head, and read my compression and still get 90psi, can I re-open the head, try something else, close the head, retorque... ? 

The reason, is that yes I want to lap the valves and do it all, but likely over the winter if possible.  So I would like first to only change the gasket and see if it improves the compression.  However if the gasket are single use, I won't do it.

Now to the gasket installation.  When I install the gasket, do I put it dry surface against dry surface ?  Should I "wet" them with something ?

thnx for the answer so far
cheers

[rb550four]

  If you are going with oversized rings.... the jugs will be going to a machine shop to get bored. They should be doing a crosshatch hone when complete. You should send the piston and rings along with it.
  I would never use the same head gasket twice. You could, if you want to do it over again. I find any gasket is a one time affair.
  Did I read in this thread that this engine has tons of miles on it? Do you know if a valve job has been done before?
do you know how many times the PO may have lapped them? Why not take the entire head with you to the machine shop and see if it would be possible to do a proper valve job( if there is anything left to work with) and find out what all this stuff may cost so you could decide if it's in your budget now or if you'll be able to save up for it. There may be one or two very busy members that are machinists on this forum ... but I can't speak for them or have any idea what they would charge. Anyone have any other ideas? now's the time to jump in.
 Or then, you could take a chance on Ebay...but can you really be sure what you're getting is better than what you already have?
  Life is complicated, motorcycles should be fun.  You just have to figure out  what you can and want to do with this machine. You could do it right and could love it forever, or  not, and sell it as an unfinished project someday. It's up to you. Lots of guys get on the fence at about this point.     If you didn't know, you're at the crossroad now.
 I hope you finish this bike.

[Azzarius]

Hi Rb,

thnx for your input.  For the PO, I have no idea what he did before I got the bike, but yes, there was a lot of mileage on the bike(140k).  As for the budget, it's not necessarily an issue.  What I mean by that is that I bought the bike to do it as a project and to learn mechanic and have fun doing it.  So for me, to bring it to a shop to have it done for me defeats the purpose.  I paid 500$ for the rig to start with, so if I succeed in turning it into a nice project and learn along the way great, I would have achieved what I wanted to do.  If it fails, I would have only lost 500$. 

That said, I've already learned a lot, and the more I progress, the more I see that I should be able to get it to where I want it to be.  Only I want to do as much as possible myself. (meaning if I had wanted to just ride a bike of that style, I could have bought a motoguzzi or an already made cafe; It's nice and all but personally I don't find pride nor reward in buying it as anyone with $$$ could do it) So that's is why I'm not too incline to go to a shop to have stuff done for me on the bike.  I want to do what needs to be done but I don't want to do what is unnecessary just for the sake of doing it. 

So from what I understand, I don't need to go with oversize ring unless I want to machine the engine ?  The plan would be not too in my case, thus normal ring.  Should I just change them with new ones?  Is that what people typically do when they open the head ?

As for the valve,(I don't know if the PO did anything here either) I'm not sure if I'm reading too much in what you said, but it seems that the valve can only be lapped so many times ? How would I know ?  Should I try it anyway (to lap the valve) ? 

thnx
Cheers

[rb550four]

Hi  Az,
  I'm afraid there is an un- understanding here That I feel needs clearing up.
Lets start with the  rings. Rings are not the only part of an engine that suffers from wear, the cylinder walls also wear , and not always evenly. This means you just can't install a oversized  set of rings on a piston,  force it it the cylinder and expect it to work. Without knowing how much wear you actually had you won't know   what the next size available rings  would be needed..... The jugs will have to go to the machine shop to accommodate the upgrade, you can't do it at home. How would you? The cylinders will be bored round again, and if you send the jugs with the pistons and new rings, the machinist will make all the correct cuts making the cylinder size correct for your new ring size.
   And yes, valves can be over lapped, the head can be ruined by over lapping. That's why I suggested you bring that high miler head to a machine shop with the above mentioned, and let them tell you if there is enough meat left on those parts to put some fresh edges on. This is also something you can't do at home...unless that's what you do at home.
    An engine rebuild  requires new parts and/ or upgrading the old parts by machining the worn parts. Just because  one takes an engine apart ,then puts it back together , doesn't make it rebuilt. Problems aren't solved and the life expectancy is even less than before it was disassembled. No improvements have been made so why would it run any better?.
     And hey, I want to tell you , I'm not the smartest guy here, and I'm  not seeing much  input from other members that know allot more than I do...am I missing something here.... Is this a spoof?  Reuse gaskets , stuff in oversized rings, no machine work, no new parts.... Not funny.
                               
   

[Azzarius]

Hi Everyone,

Once again, thank you for all the input and explanation.  I did listen to part of the advice received.  The time being a question(Trying to make it to the Distinguished Gentleman's Ride next week end; http://www.gentlemansride.com/ ), I decided to try mu luck and skip(for now) the lenghty(and more costly) run to the machinist and do what was in my power.  So rings and cylinders stayed the same(as I don;t have replacement for them just yet).  I knew that my head gasket was bad and based on some of the comments the valve were likely due for some TLC.  So I proceeded and did just that. 

Lapping the Valves
Turns out that my normal go to store(Canadian Tire; in Canada) do not carry lapping paste/compound anymore.  I was a bit stuck, then I remember that there was a Stihl(small engine) shop near my place where I got my yard tool.  I went there and spoke to the guy who landed me a can of lapping compound (that he, himself, got from his father =-) ).  So all that to say that I have been able to do the valve job.  There on some a lot of gunk.  Some had a crust that was very hard to remove.

Head Gasket

Then I changed the old head gasket that was leaking by the new one.  Put the whole thing together and it looks like it did the trick, as the bike starts and runs.

I did however, redo a compression test and the result were about the same.  So I'm not sure f the problem is with the engine or the gauge.

I would still have to vaccum balance the carb, but it runs for now and should be ok to go through the week end ride.

I will try to change the oil pan gasket as there was a new one in the gasket kit, and I realised that when the oil gets hot(more liquid/less viscous) that it leaks from one side.

But yes, the whole ring, piston, piston chamber thing, will likely be part of this winter project.  As RB mentionned, and I understand that this would be the crossroad for many.  I guess depending on what is your goal, these steps might become a deal breaker for some.

Still there should be more to come, I still want to get rid of the 4in4 exhaust, as it is ugly, I need to get a tach/speedo on it, new tires, side covers that I want to build...

Cheers
 

[Azzarius]

Hi Everyone,
Wow I didn't realized that it had been that long since I've update you on the build ... and that I had been stuck with my problem.  Still, here I am back at it.  Update I've got another engine, in half decent shape.  At least, by the check of the mechanic, the cylinder chamber is much better with the pistons and rings from that new engine and is in spec tolerance.

I've put together the head, with this order: if we look at is as if we look at the engine itself

Old cam cover
Old cam head
Old valve cover
"new" cylinder block (plus "new" pistons and rings)
Old crank case

The engine compression is as crappy as it was ~ 80-100psi per cyl. 

However the leak down test was much better

Now I've also got myself a Leak down tester.
cyl#1 --> 90/92 --> 2-3% leak
cyl#2 --> 89/92 --> 3-4% leak
cyl#3 --> 82/92 --> 11% leak
cyl#4 --> 86/88 --> 2-3% leak

Ok I have one cyl that is not great but still within the 15% recommended and within 10% of the others.  Yet my compression is crap ... so what's next ?  I'm a bit at lost here.  Anyone with great idea? Lesson learn with similar issue ?

thnx

[Azzarius]

Hi Calj737

Here are some answer to your questions

was the test performed with a fully healthy battery?
The battery has been charge lately so we could assume yes.

Were the throttles WIDE OPEN for each test?
No, but the carbs are no even on, so it's as if it was.

Has the motor sat for a while?
I've just put it back together few weeks ago(3-5wks)

Are you using a motorcycle-specific tester?
Not sure if it's bike specific.  This is what I used
http://www.canadiantire.ca/en/pdp/equus-3612-compression-tester-kit-0251016p.html
it's called Equus 3612 Compression Tester Kit .

How long is the hose?
about a foot long.

Did you pull the plugs and examine them for the tests?
I've removed the spark plug (all of them for the test)

Are you running these tests with, or without carbs installed?
No carb, not exhaust.

cheers

[Azzarius]

QUick update. 

I've put an exhaust and carb on and it run when started with a Quick Start spray.  Once warm it runs on it's own.  I wanted to give it a go around the house this w/e but it seems that the weather is not cooperating(Montreal -8C +snow +freezing rain)but next w/e 14C + sun =-)

cheers

[Azzarius]

Hi Everyone,
Fuel Tank
I've finally invested some time in getting my fuel tank ready and painted it.  I you might recall from earlier post, I was looking to have the tank painted Fiat Mocca color.  This would have ran me down around 300$-400$ professionally or 100$-150$ if I would have attempted it myself.  So before going crazy and during my research, I though about Vinyl wrap,(~150$), then I came across Plati DIP.  It was the first time I saw that stuff and for the price 8.99/can in US or 25$/can in Canada(yes, we are getting screwed).  I decided to try my luck and give it a go.  As you can see my filler job is less than perfect on the right side but still I can live with that.  The result after a plastidip Camo Tan is very pleasing.  Some warned me that it will not last long.  But For 10$ it's worth trying and changing color if I don't like the first i pick.

Note the first 2 tank close up are only grey primer.

cheers

[Azzarius]

Hi Everyone,

Fuel Tank leak

As I was about to work on my exhaust wrap, I've saw a smudge on the side of the tank.  I though it was just a dab of dirt, so I wiped it off only to realized that it was my PlastiDip that had melted.  Likely culprit, the fuel.  Turns out in looking closer that there is a needle size hole in the tank. 

Anyone with advice on how to easily fix that ?  I've read about the liquid interior liner, or even welding, but at this point, I would like something like a drop of magic glue to seal it.  Anyone with similar experience ... and solution that worked and didn't ?

Cheers

[SOHC4 Cafe Racer Fan]

Hi Everyone,

Fuel Tank leak

As I was about to work on my exhaust wrap, I've saw a smudge on the side of the tank.  I though it was just a dab of dirt, so I wiped it off only to realized that it was my PlastiDip that had melted.  Likely culprit, the fuel.  Turns out in looking closer that there is a needle size hole in the tank. 

Anyone with advice on how to easily fix that ?  I've read about the liquid interior liner, or even welding, but at this point, I would like something like a drop of magic glue to seal it.  Anyone with similar experience ... and solution that worked and didn't ?

Cheers

Empty the tank and line it.  You can use Caswell epoxy or (waiting for Cal to chime in) there is a alternative that is less "thick."

[Azzarius]

Hi Everyone,

Update Fuel tank

Since I live in Canada and everything is about twice as expensive as it is in the down south, I will settle for POR15, which was one of the less expensive product.  Also, it was one available in Canada.  Most of the other one didn't want to ship cross border.  Probably because it is consider toxic material or something along those line.  Anyway, shoudl get the product soon.  I'll update you on the process.

Cheers builder

[Azzarius]

Hi Everyone,

another quick tank update
Trying to empty the fuel tank last night an regardless how much I swirl the tank to try to move the fuel on the right side where the petcock is, it seems that there is always some fuel left in it.  What's you best way of emptying a tank?  Siphon? upside down via the cap(I was trying to avoid this since I didn't want the fuel to touch the paint(It's a dip paint).  Next I was thinking getting the hose in it and starting cleaning with what ever is left of fuel, so at least when it come out of the top, it will be so diluted that it will not affect the paint.  Any trick/pointer ?

thnx
cheers

[Godffery]

 If you have compressed air, you can create a vacuum siphon with a blow gun, a couple feet of rubber hose and a strategically placed slice in the hose.

After sealing about 2 dozen tanks, I'm a big fan if the POR-15. 

[Azzarius]

Hi Everyone, (Godffery)
Update fuel tank

I used the blowgun/small tube to clean up the most water out of it and then I run the blowdryer for few hours in the sun.  Then I coated the tank with POR15.  It says it takes 96hrs to completly cure.  So I'm waiting now... I did let the blowdryer runing for about 48hrs in it.

I'll update later with pictures.  I found a youtube that also explained how to fix the dip paint on it with paint thinner.  So I've re-spray painted the affected area.

cheers

[Azzarius]

Hi Everyone,
Fuel Tank Update

So the tank is dried now.  I will have to clean the bottom where the excess has dripped.  My concern is that the "orange" plastic filter that goes over the petcock straw was already a tight fit.  So I assume I will have to force it hard to get it back in as the inner wall of the connector pipe will have been coated as well. 

On the other hand, I've re-painted the area with 3 coats of dip and it seems to have cover it well.  Unfortunately when you look from very close, you can still seem some of the difference in height when the fuel had dissolved the Dip.  But it's almost under the tank so not a much visible spot.

cheers

[Azzarius]

Hi Everyone,

another progress update.  I've wrap my exhaust with the wrap I bought over a year ago. Finally.  Now the pipe is still "scratched chrome", because my local shop for powder coating is very busy. I would like to get the pipe and the chain guard powder coated.  It will be more resistant than just paint since it's where I always have my feet rubbing and also for little rocks that flies around. 

Next, I need to buy new tires.  The one on the bike looks like they are 20 y/o +.  The problem however is the size of those tires.  There aren't too many good looking(to my taste; I'd like to have something knobby like Kenda K761 or Shinko E705 or Avon Trailrider or continental ContiEscape or Metzeler Tourance) tire that fits the sizes(front 19" rear(this is the problematic one) 16")  All of those tire have the 17 but none 16".  I found the Bridgestone Trailwing 40.  Not the prettiest but still. 

cheers

[Azzarius]

Hi Everyone,

Tire
So as per the previous post, I finally got my T39 and T40 tire installed.  The look is nice.  I'm now thinking maybe changing handle from clip-on to some sort of "tracker style", it'd be a bit more comfy to ride and might not look bad either.  We'll see.

Problem starting
So after sepnding quite a bit of time fighting to start the bike, I was able every now and then able to get it to work, mostly with choke "full ON" and with a lot a starter fluid.  Spent couple evening watching youtube and reading posts and few things seemed matching the behavior.
- it runs only on choke, thus, i must run too lean (not enough fuel/ too much air)
- it runs with starter fluid, thus, it lacks combustible
- stall when giving gas, thus, idle jet must be gunked
Most blogs and video said it's 90% chance to be carb.  But I had cleaned the carb some time ago.  Then one vid mentioned that without stab fuel could gunk in as little as 6-8 weeks.

Sure enough, 3 out 4 carb had their slow jet completly plugged, and the main also needed some TLC.  Clean all of these guys, and now the bike starts, no starter fluid, runs ok, rev up ok.  So I am very happy and excited about this after few years of on and off work.  Sure it's not perfect, I would still have to balance the carb and all, but just the fact that I can now run it "without being too worried" that it will die on my.  I still ride it within 5-10km from home for now, so if I have to walk it's not going to be too  bad =-).

Next maybe cleaner electric installation
I've seen some very nice installation on pinterest. I would like for mine to look that clean.  I've put below what I'm talking about.(the pic of the electric installation is not from mine)

cheers

[kslrr]

Beautiful job on the electrical tray!

[Azzarius]

Hi Kslrr,
Like I said I wish it was mine =-)(it's from Pinterest). But it give me a target as too what it should look like.  That's the next thing I will try to do on the bike.

cheers
 

[Azzarius]

Hi Everyone

Electric/Electronic
Like I had mentioned before, I would love to have a cleaner installation "a la" picture in my last post from Pinterest.  In looking into getting what I need I realized that the motogadget brain ranges in the $300-$400 USD.  However nice that box is, I can bring myself to spend so much for "so little".  I double quote  because, I understand that to package something similar, someone had done the work for it and they must not be selling zilions of those unit, so the R&D needs to be absorb on very few units and it is still a very decent product from what I have been able to find.

That said, I'd still like to have 1 or 2 or similar features that are available.  Those features are:
- Not turning the headlight until the engine is started
- pulsing brake light (better to catch driver's attention)
- possible nice blinker sequences

I will try to replace it with a cheaper solution:  Arduino Micro(programmable microcontroller) ~$13.
nice fuse box ~10$

I just started, so I will keep you posted on the progress as I go.

cheers builders