Topic: Iain's 1979 CB650 project log - 118 Pictures

[IainC]

My bike is a 1979 CB650. Bought it summer of 08' when I moved back to Nova Scotia from Ontario. Ended up selling my 350f to buy it, since moving the bike would have been too expensive to ship. This is one of the only pictures I have when I bought it. Rode it as it was, with the exception of an oil change, some tuning up and a good cleaning.



So I picked up a second 650 for parts. I got lucky and managed to find managed to find another 79, so any engine parts should match identically. I don't have the title, but the guy who sold me it says he has it somewhere, so I told him to knock 50$ of until he finds it. So 200$ no title, I feel I got a good deal as I could have easily spent that on other parts I need on ebay. Here she is when I got it home.



My friend Brandon and I quickly got to dismantling the entire thing. Took us the good part of our Monday afternoon, but we had great weather and some extra help lifting the motor out. A quick list of interesting parts.

The front fork assembly will be swapped on. Dual disk in the front, with drilled rotors. I'm not sure what kind of brakes are on it, but I did see Tokico stamped on the bracket piece of them. I'm also unsure what kind of master cylinder is on this. I suspect the front end may be off a later model cb650, as the P.O. Mentioned buying 6 of these bikes as a lot with a friend of his.





The exhaust setup is a 4-1 with a Laser can on the end. This is great as my stock exhaust is a rusty mess on the bottom and has some holes. I have a friend with a second 4-1 for me, but this one looks like the can is easy to swap.



The handlebar came with these chunky risers. May use the bar without the risers to see how it feels for a bit, although they are nice to have.



He also gave me 2 seats for the bike, that both hook right into the stock hinges. One is an uncovered cafe style single seat, the other looks like a stock pan that was hacked up and he tried to make his own fibreglass tail. Should be fun to work with these.

And then we come to the engine. It's been clearly sprayed with some sort of black spray paint. Some of the paint is rubbing off, and its not hard to scrape. Looks like someone used some liquid gasket to seal some of it off. I hope they didn't go too crazy. Looks like the head gasket needs to be replaced (surprise) as there seems to be a bit of oil leaking out. Turns over no problem.

[IainC]

We don't know how well the motor works, so we decided to swap it into mine and give it a shot. The first tear down was easy enough, so Brandon and I pulled the engine to get the new one in place.

Got the engine in with a bit of struggling, but its in now. We had the carbs installed with the airbox. Got some fuel feeding into the carbs. First thing I noticed was a bit of a leak pouring out of the bottom of one of the bowls, and a big stream from the new fuel line we installed. With a little tightening of the hose clamps, and screws on the carbs, the leaks seem to be gone.

Engine wouldn't start right up for us. We pulled the plugs and they were dry, so splashed a bit of gas into the cylinder and got combustion. Got spark on all the plugs. Seems we have a fuel delivery problem.

I had torn my carbs apart and cleaned everything. Soaked in a combination of water and simple green, I  let them sit and then took a brush to clean them, and blew air through all the passages. It seems now that the are reassembled, I have the choke hooked up wrong. For it tends to feel a little stiff moving, and they don't seem to be moving in sync. I think I may have a spring set up wrong, and will take pictures later to show you my problem.



I took the airbox off, and sprayed some carb clean through them. Let it sit over night on the trickle charger, and gave it a shot today when I had a couple free minutes. This time it seemed to be getting fuel and sputtered a little bit. I didn't have time to sit and play with the choke and throttle as they need to be hooked up again, so when I do I'm feeling optimistic it will run soon.

When trying to start the engine, I noticed the starting motor will slip and spin off if I push it too hard. If this engine is the one I end up using, I'll swap it out for the other one.



The points have been replaced by what I guess is a CDI ignition. Can I use the coils that I have already, or should I swap them for the ones on the parts frame? They are clearly different, and I'm unsure which are the better set to use.


Could you help positively identify the parts for the front end. I want to order fork seals and brake pads but I'm not sure exactly what I'm looking at. The brakes are stamped with Tokico on the mount part. The forks look just like mine except painted black, and both sides have brake mounts. I'm also unsure about this master cylinder and would like to rebuild it.

[IainC]

Can anyone identify my forks? I want to order new fork seals, but don't know for sure what they came from. Do the 750's and 550's have the same looking forks, or just the 650's? Are the fork seals all the same, or is it different for the air forks?  Thanks guys. 

[cb650]

Everything looks stock 650 except the holes in the rotor.   The air and non air forks used the same seals.  Check at honda when I got my last set.  The 650's had "CDI" iggs stock.

[IainC]

Thanks CB, I'll just order the 650 seals and hope they are fine. As for the ignition unit, I find it strange that I have two 79 650 motors, my original one has points but the one off my parts bike has the electronic ignition system. I suspect someone must have had a later year and thats where the forks with dual brakes, and the ignition came from.

Last night I got some more bondo work done on my gas tank. I had started it last fall, but it was getting too cold to continue and I lost motivation. I find it difficult to find and even out all the low and high spots, but will keep at it untill I get it perfect, or at least as best as I can tell. I would try spraying a thin guide coat of paint over it, but it's far too cold out to spray anything. I'll get pictures later but for now I'll post one from last fall.



I also started work on recovering one of the seats I got. Striped all the old foam off the seat pan. I picked up some great foam at the fabric store. It won't discolour, water resistant, mildew resistant, and fairly easy to work with. It's meant for outside cushions so suits my purpose fantastic. I'm not sure If I'll hold off on shaping and attaching the foam until I can get the seat pan sand blasted, or if I'll just clean up the couple of rust spots with sand paper and spray some black tremclad over them.

[cb650]

Someone musta put points on your 79.  Every one I've come across had the cdi. In the repair manuals they dont even mention points. The 81 custom and 82 nithawk (custom replacement) had dual disks.  The euro Z's (like a 79 z) had dual disks with the regular comstars.  The tank on your parts bike looks like a nitehawk tank.

[IainC]

Someone must have put points on your 79.  Every one I've come across had the cdi. In the repair manuals they dont even mention points. The 81 custom and 82 nithawk (custom replacement) had dual disks.  The euro Z's (like a 79 z) had dual disks with the regular comstars.  The tank on your parts bike looks like a nitehawk tank.

That's a good point CB. I just assumed that points were stock on the early model 650's. Strange that someone would swap them out.

As for the tank, it clearly doesn't belong with the bike, but he had it sitting there so I figured I would take it and could find someone who can use it.

I just put an order in with partsnmore.com. I've ordered parts from them in the past for my 350f, and love that they offer free shipping in Canada. The list is:

       18-0202  GASKET SET - HONDA CB650 (79-82)  $86.00
       05-0001  THREE BOND GASKET SEAL #4          $7.00  $7.00 
       49-0281  BOLT KIT - 20 Pieces - CB650          $9.00  $9.00 
       15-0002  OIL FILTER - 15 0002 - (*THREE OF THESE*)         $3.00  $9.00 
       23-0404  Front Sprocket - 16 Tooth          $17.00  $17.00 
       22-0301  Rear Sprocket - 40 Tooth          $29.00  $29.00 
       28-2011  STEERING BEARING KIT          $40.00  $40.00 
       29-0051  MASTER CYLINDER RESERVOIR REBUILD KIT          $34.00  $34.00 
       29-3521  Brake Pads          $16.00  $16.00

So once these arrive I should have most of what I need, except for new tires, a chain, and any cosmetic changes.

[cb650]

After looking at the parts bike more check the year on the frame.  Looks like a 79 frame with a 81/2 frontend and the nitehawk tank.   The 80 up (non Z models) had the air filter on the right side. And it has the 79/80 carbs instead  of the 81/82 CV's.  Only thing that dont look right is the coil.  All my 650 coils have the plug leads on the end and not the bottom.  As for points something probly went out in the elec iggy so they swaped a points set up onto it.  I seen a 80 with a drum front brake once and that sure wasnt factory.

[IainC]

It's a 79 frame and motor for sure. One of the first things I checked were the serial numbers. It really is a mix of parts, and I hope most of them are from a 650 to keep things simple. I also got a box of 2 sets of the later carbs, as well as another set of the original carbs. My original coils are the same as yours with the wires on the end not the bottom.

Thinking about it now however, I remember reading how to adjust my points in my shop manual. Maybe the early 79's had points, or at least the Canadian models?

[cb650]

Neither of my repair manuals mention them.  The haynes even lists the 650 from 78.   Just looked at the honda shop manual also.  No mention of points.  I'm sure its something someone buggared up.  I think the 750 or 900 coils are like the ones in your pic.  On the dohc750 site they talk about using a gm coil to replace and they have before and after pics.

[IainC]

We managed to get the second engine running, although it was belching out some blueish smoke, and not all cylinders were firing. I've taken the carbs off again and gave them another cleaning, but still need to set my float heights. I'm finding the manuals are not the easiest to follow for setting up the float height, and gives me vague measurements but dosn't indicate where to measure from.

The other problem we ran into with this engine is related to the starter motor. It seems to crank it over, but after cranking a few times will make a loud click and just wind down. Sounds like something may be slipping or giving out. We swapped it with another motor but found the same problem.

We will keep at it to see how well smooth we can get it running, and decide from there what to do. The other engine I already had, will run, however it smokes a lot. Whichever we end up going with will be getting the gaskets replaced. I haven't decided on the piston rings yet, as they are a pricey part to order, and I'd rather not have to drop 200+ where I could put that towards insurance or tires, etc.

[cb650]

Check evrything on the engine with the starter problems.  You could swap everything to narrow it doen but there is always the starter clutch.  Run the one that smokes the least and go through the other when you have the cash.  Most likely the valve seals that come in a top end kit.  As for the float hight its measured from the bottom of the float to the "gasket surface" where the bowl sits.

[IainC]

So a bit of an update. Cleaning and setting up the carbs seems to have made a big difference. It will start up a lot easier now, even without the airbox installed. It idle's very high but I'm guessing thats likely due to it needing a lot more tuning.

When running I'm getting a loud clicking noise, but it's not a regular noise. The ticking seems to be fairly random, but very noticeable. I haven't let it run too long like this as it dosn't sound very good.

As for the starter, other than swapping the starting motor out, I haven't spent much time troubleshooting it. But it does sound like its getting worse and slipping more frequently the more we try to use it.

I think we may tear both engines apart, using the cylinders and head off the new engine and transplant them to my original one. The original motor at least needs a new head as some of the bolts holding the covers on won't screw into the stripped holes.

I'll have to get more pictures just to make the thread a little more colourful. I know how much you all love pictures, but it's pretty ugly looking now as I've been focusing on getting it to run soundly. Not to mention it's still too cold most days to paint.

[IainC]

Some more pictures I took and am finally uploading.

This is one of the seats I got. It fits right into the stock hinge and seat lock. When I got it, it was uncovered and the foam is a little gross.



The seat pan I am getting sand blasted tonight and than I can start building up the new foam.



This is the foam I picked up at my local fabric store.



You can see here how I've pulled in apart in sheets. It came as one piece, but I think will be easier to build up and glue together in thiner sheets like this.



And finally a picture as it sits right now. That engine is coming out the be replaced with the other. The side covers and tank are getting close to ready for paint. Lot's of cleaning and making pretty left to do, but that comes after I'm done with any mechanical work.



And here is a concept I threw together last night to get an idea for the color scheme. Going to keep it simple with a dark charcoal with a metal flake.



Does anyone think I could get the printing off the muffler? I'd like to strip the logo off and either leave it plain, or respray it to say "CB650".

[V4 Lover]

Get that bench built so we can get started on the motors! 

[IainC]

Unfortunatly I'm working 3-11 all week, and 2:30-10:30 this weekend, so free time in the evenings dosn't really exist. Maybe we can throw something together tomorrow, I work early because I have a dentist appt so will have the evening free. The parts I ordered should be arriving tues or wed, and with Wed off that will be the perfect opportunity to start tearing into it.

I just got word back from a friend, that I may have a paint job for free or practically free, airbrushing and all, so my plans may be changing in terms of colour scheme. Don't want to go into too much detail as it's not finalized but I'm getting excited.

I had my friend invite Brandon and I over to his ship with the coast guard and took advantage of their bead blasting cabinet to clean up some parts. It cleaned the paint off them fairly easy, but wasn't super powerful and had issues with the header paint and rust spots. I'll get the last bits we missed with sand paper myself.

[IainC]

So it's a go for sure. Going to contact the painter in the next couple days to set up a meeting and discuss some ideas. I'm not sure what direction to take with the paint but having an artist share his concepts might get the gears turning and help me decide on a colour scheme.

[V4 Lover]

Maybe you should get him to airbrush some gears on it or something? All bronze Gothic machinery and #$%*.

We gotta get this engine stuff done so we can get the front end ready. Maybe you should draw up the bench design, and get your dad to sign off on it. Shouldn't be hard to do a little bit at a time, or just cut one morning, and assemble the next (especially if you have all your measurements calculated).

When we clean your forks we'll do mine at the same time. Gotta set my sag as well. You'll have to do some research into the best settings for yours. Unless the only adjustment will be shims/oil level/air pressure...

[IainC]

A quick update.

Brandon and I were in the garage untill 1:00am last night tearing into the engine. We took lots of pictures, just need to get them uploaded tonight when I'm home from work.

We managed to get as far as the head off, and almost ready to split the cases. I'm going to have to buy a socket to make a tool to remove the clutch, so we can finish tearing it down and see how the guts look. I'll try and get some pictures up asap so you can see what we are working with.

[IainC]

Pictures!!



This was the contents of my box from partsnmore.com. I realized I only ordered one set of brake pads  so I'll have to order more. Still need a new chain, and some cosmetic parts. Other upgrades will come with time.



We are just using a small work bench to hold the engine. It's easy to drain the oil out as it doesn't have a flat top.



Covers off, about to start tearing into her.



Off comes the cylinder head cover, wait... whats this?



This nasty orange goo looks like liquid gasket or something. Better clean that out.



Camshaft out, chain suspended by a screw driver while we get something to tie it back with.

[IainC]

Alright, time to take off the cylinder head.



We used string for my grass trimmer to tie up the chain and hung it from a light we have hanging above us.



Looks like the valves need some work. Look pretty dirty too me.





Pistons appear a little nasty as well.






Today we managed to remove the clutch basket and start measuring the discs to make sure they don't need to be replaced. Not sure if they are within spec, think my manual is wrong or else my discs are way off, I don't know how it's even worked. When I know for sure I'll post the correct measurements.

Also picked up a bunch of supplies to start cleaning everything and prepping for paint. Got some primer on my triple trees as I stripped them to bare metal, I'll get some paint on them tomorrow.

So the to do list right now is:

Finish getting tank and side covers prepped for paint
Clean up and lap valves
Clean off pistons and make sure they and the rings are within spec (if not check other engine and swap cylinders and pistons if necessary)
Degrease and tape off engine for paint
Get engine back together with new gaskets and seals.

Then I can move onto getting my front end swapped and rebuilt. 

[IainC]

And we've got all of 20 days left to be finished!

[IainC]

Update:

Finally a few problems. 



First off is a problem I ran into while checking if my pistons were still good to use. Got the rings offs.



But broke one in the process 



Then we decided since I've gone and broken a ring, we need to tear into the other engine and either use the cylinder head and pistons off it, or just steal one of the rings. Gasket remover is crazy stuff.



Everything went quite a bit quicker the second time around, until this happened. Great, nasty broken bolt, good thing I'm not using the transmission off this one.



And just to top it off, I went out of my way today to go to Princess Auto to buy a valve spring compressor, in my haste bought this cheap piece of crap, that turned out to be too big.  I should have just bought the good one.

[IainC]

Here's some close up of the piston sleeve's. Does the discolouration indicate any sort of wear?



The red on the piston skirt is not a reflection. What does this indicate or what could it be?



And one last picture of something that doesn't look half bad. Got my second set of triples bead blasted, got them painted with some aluminum coloured paint. Should look good against the black frame I think.

  Question Time: 

Any tips for removing those rings to check the gap? I was pulling them apart as directed in the book, but may have been a little over zealous in how flexible I thought they were.

Would it be a big problem to use the second ring off a different piston to replace the one I broke as long as its still within spec? I understand they wear to the cylinder, but would I be asking for big trouble or just taking the chance it will wear out slightly or significantly faster? 

[IainC]

Just a quick update.

Been working pretty hard to get this bike finished for next weekend. Our local motorcycle trade show will be that weekend, and my goal all along has been to have it ready for the show. I don't expect to have it to a point where I can win any prizes in the show and shine, but I still want to be able to enter it for the fun of it all.

So long story short, we got the valves taken apart, cleaned all the carbon out, gave it a quick port and polish job, nothing too insane but it's in much better shape then when we started (I hope, haha). It seems there is always something I need to run to the autoparts place for, be it assembly lube, oil, cleaners, or just brushes.

Also got some more engine parts painted, and more parts ready for paint (I hate degreasing with a passion now.... far too many hours hunched over my engine with a brush)

Lastly I met with my painter last night and got the tank and side covers dropped off to him after having the body work done by Brandon's grandfather in exhange for an afternoon of heavy lifting.

I'll try to update tonight with pictures, I've been taking lots, but haven't had much time at home to get them up. What time I do have is all being spent in the garage.