Topic: My '79 CB650

[Soos]

The latest update..
Sorry no pics right now, as my digi camera finally met it's demise...


Got a flat in my front tire, so for the past week it's been in the garage.

I have put my ported head on the 650.
While I had the carbs off I went ahead and thought I would re-check the starting circuit.
One was completely blocked, and one was partially blocked.
Fixed both of those, slapped them back together and put them on this nice ported head.

Figured out why my O2 sensor was erratic, even after warming up.
Gotta keep the O2 sensor connector covered so it doesn't ground out to the frame.
oops.
 

Removed my tachometer as well.
Thats a scarry thing...revving the motor up with no tach listening to the motor top out bouncing off the rev limiter.
I took out the tach gear as well. no need for it rubbing if it's not doing anything.

By the way.
NEVER run a motor with the tach gear out, and nothing plugging where the tach cable goes. Unless you like the smell of burnt oil on your exhaust.


I made a cool part to plug the hole where the tach cable went.
I wish the camera worked right now....


Oh, and the startup problem the GPZ carbs had been having, is now solved by finally properly cleaning ALL of the starting passages.
Waiting for a bitter cold morning to try them out on now.


Going to do a paintjob this winter.
thinking a simple 2 tone black/white combo.
Not sure.


l8r

[ghost]

lookin good. glad to hear you got your head changed, and those ninja carbs all sorted out. i'm still lookin for another set of carbs for mine(hopefully this winter) i don't think your gonna have to wait long for a good cold morning, hope everything goes smoothly. 

[Hush]

Bike looks good Soos, wanna come over here to NZ and sort my two basket case 650's out?

[StrongPerf]

Nice work Soos. I'm posting to stay informed. I like your project!

[RM81]

Good thread and great progress.  I'll be reading this one through again when I sort out the electrics on my 79 cb650.  Do you know of any more reliable after market replacements for the CDI's on these.  I hate to just fry another set.  The ones I have came fried by the previous owner.

[Soos]

The only replacement parts I have found are other CDI units...


Unless you want to put a dyna2000 on your cb650.
It eliminates the spark units completely.
FOr a week or so I had them in, until I realized the citcuit to them was pretty much inoperable for a couple of reasons.
I'm no electrical whiz, but since the stock timing unit was no longer hooked to the bikes wiring harness, the CDI's never got any signal to fire the coils.
Was checking(or adjusting) something, and realized it.

I immediately took them off, and started her up.
Smiled, and went for a nice long ride realizing that I no longer need those for this bike.
 

l8r

[Soos]

Well, A update(few and far between they are)


Been starting the bike when its over 40 degrees with a fan on the motor and letting it run for long enough to get everything to hot running operating temps.


Got a freiking head gasket leak now.
But what do you expect with not only an aftermarket gasket, but this is the 3rd time it has been installed.
Suprising the 1st AND the second times I torqued this gasket to a motor, it held amazing well.
Now.... get the motor hot, and it weeps along the 2 outer oil galleys.
Oh well.
When I replace this one I will either go with a cometic gasket, or with a genuine honda one.


Plan on pulling the rockers off to re-torque the head before riding season.
Who knows it might work.


Carbs are starting well still. even in low temps(as long as the battery is charged well)

I have my Michelin Anakees mounted now!


I was going to put them on the bike yesterday, but I wanted to make that sight thingy someone posted a few weeks ago.
I used aluminum, and it's basically a clamp  with a pointer that goes on the rear gear allowing you to sight in the front gear and align the rear tire properly.
The one that was posted had a rod as the line of sight tool.
I went with 1/4 OD stainless tubing mounted through the "clamp".

I made sure to machine it so it would accommodate the biggest chain dimensions for a 530 I could find on the 'net.
If I get a bonus this year, I will be buying a mill and possibly a lathe if things work out.
I may start making these for sale if /when I get a mill.


I have gotten a K&N air filter replacement for my '79 as well.
Should be a better option than the gutted filter I was using(just the flange and the wire mesh, all the paper media removed)




Thought about cleaning the bike really well before this season...
Fark it.
Lubed the swingarm, rear carrier bearing, replaced the fork oil, and about anything else that needed it.
Had to adjust the tapered bearings in the head a bit.
But I expected that, last season was the 1st riding season for them.


Have thought of replacing all the fuses to the bladed style, simply for new connectors, and convenient replacement.


Lovin' the dyna2000 still.

Managed to (stupidly) leave a spark plug wire off the plug, and ran the motor.
By the time I realized that it was off, and laying on a hot exhaust pipe, the silicone cover for the spark plug melted through.
I put it back on the spark plug after turning the motor off, and it started arcing to the motor where the boot had belted through.

Put in other wires hooked up a set of resistive boots, and side gapped a set of plugs I was about to throw away.
I can't say I notice anything different, but I can't go for a ride right now either.
Might run them this season. Dunno, I really like how those iridium's were doing up 'till the wire went south for one of them.
They run, and I got to touch them with a dremmel... I couldn't be happier.
 


Still trying to work out a LOUD horn.
Figured out what I need to do for the solenoid, but now need to fond a horn I can tuck under or behind something...

Thinking under the carbs, dual horns. One facing out each side.



Well, i'm off to research pistons for my other cb650 bike.



l8r
 

[Hush]

Good to catch up on what you are up to Soos, my 650 Custom has one of the loudest horns I have ever heard, seriously you can't be in the shed when you press the button it is like sonic.
Not sure if it is a standard thing on the Custom 650 but looks just like my other bike's horn?

[Soos]

HAHHAHAHA.....

Fixed one of the oil leaks(beginning to suspect this is the main/only culprit for all that oil I have been loosing!!


I had made a custom plug to go in the place of the tach cable... solid stellite at that...
Need to figure out htis new camera... well worth a picture.
can't even find a link to a similar product.

Who needs a tach with a rev limiter?
Although it's kinda unsettling shifting by sound and not even being able to see what the tach reads!!!


But anyway, I had pulled the tach gear as well, figuring it's not needed, and however little, it robbed power I could be putting to the road and not in a spinning gear going to nothing.


Well I noticed today (while revving the engine to se where oil was coming from( I saw oil POURING out where that plug is when bouncing off the rev limiter.

ARGH!!!!
I pulled it, and remembered I should have made a o-ring groove to help it seal, and was kicking myself in the rear for not having done so when the part was in the lathe initially.

Well, I figured If I have to re-chuck the plug, I was going to just re-make a whole new one and eliminate the tach gear housing at the same time with the new plug.








........................................................then I noticed the oil groove, and the oil feed hole for the tach gear, and the oil seal just under where the tach cable sits in the housing as well, and realized by pulling the tach gear out I had caused a high pressure oil feed behind that plug I made.... with no o-ring to seal it.

Put the tach gear, and plug back in, buttoned everything back up, and the leak is gone now.
 
I figured that was the better option than plugging that oil feed galley with something....


The more oil to the head the better.... but the loss of restriction in one place in the oil system will kill the pressure in other areas... and the head is NOT a place to loose oil pressure being fed to the cam.





Now I get to clean the engine AGAIN, and put more talc powder on everything to see if it was just that or if the head gasket is actually leaking or not.

Whoo....hoo! I hate cleaning it... I might just as well clean the whole bike....



l8r

[Soos]

Guess I'm not cleaning the whole bike.
I went and removed all the spark plugs.
Then loosened the head bolts and re-torqued them one at a time.
Could only reach the 4 across the front, and the 2 nearest the outside on the back(towards the carbs) without removing the tank, and possibly the part above the head.(the part that the rocker arms are mounted in)


Just a few minutes ago I took some paper towels out there, warmed the bike up set up the fan, then proceeded to poke the paper towel in between the fins.
Oil always cleans up a bit easier when warm IMO.
Got it pretty darned clean, by then the motor had been running for about 10 minutes.


...Since i wanted to hear it scream, and thats when the oil leaks show, I watched the clock and held the throttle at WOT for about 3 minutes. 
(just before I sprayed some athletes foot powder up in there to spot any oil leaks.)


Not a drop seeping out anywhere!! (so far)
Not even up near the tach gear.(where the oil was pouring from before)
God she screams. 10,300ish RPM is what she tops at... wonder why.
I have the rev limiter set at 9,900. when I downloaded the info with the curvemaker software for the dyna2000 unit it reads 10,303 as max rpm the motor went up to.
hrmm.... by the #'s I have seen 10,300 is supposedly about the safety limit for cb650 rods anyway. Might drop down to 9800rpm just in case.

I still can't convey the re-assurance that rev limiter gives me knowing that the chance of over revving is SERIOUSLY limited now.
A bad downshift is the only way to over rev now I think.



But I am really amazed a aftermarket head gasket can be mounted this many times and hold oil.
It lived about a month(less?) on one motor, then to this motor it is on now for a season, then again on this motor (put on a ported head) AGAIN.
And it holds oil.
For all I know though, it was holding well before, just the tach oil leak I had was showing oil everywhere, so I assumed the gasket.
Even after finding the tach leak, I still assumed the gasket was leaking... it was the 3rd time being torqued down.
It did come off the 1st motor well, and the head swap I didn't remove the gasket. just dropped the ported head on it and re-assembled the motor.
But with the hours of run time it has had just this winter, the re-torquing of the head bolts cannot be a bad thing anyways.





l8r

[scunny]

yeah it's a bugger having to remove the rockers to retorque all the bolts but at least we can without removing the engine.

[Pinhead]

I'm in the market for a new top-end gasket set (base gasket, head gasket, etc). Where did you get your aftermarket gasket, Soos? Is it the stock thickness?

[Soos]

Pretty sure I got it either from Z1 or or feebay.

it was a 49 piece "complete" gasket kit. a vesrah?


l8r

[Soos]

Well I took off my narrowband sensor and the guage.
Pretty useless overall.

Not having a RPM guage was really eating on me as well.
It not only looked odd with the narrowband guage where the tack went, but it's unnerving not knowing my RPM's.
(speedo is nearly 4" across, that narrowband sensor guage was like 2")


The RPM guage is a little slow on the acceleration of the RPM's, but with the motor bouncing on the RPM limiter, it reads a even 10k, right on the line.
But I think that comes from the added weight of the copper needle.

[Soos]

I had made one for the speedo as well, but gave up since the copper needle is NOT visible at night.

RPM I can live without seeing at night I guess, but MPH is a MUST.



hrmm.... the grips I bought I noticed were a bit shorter than stocker honda ones, but I like them more.
They are BSA grips.
Quite a pronounced bulge in the middle of them, seems to fit the hand well so far.
I love how well hairspray holds grips in place! Cheap too!


Had to trim 1/2" or so off the end of the throttle grip and move the controls further out on the bars though.
Might give a bit more control offroad having my hands 1" wider overall.
Dunno.
Be nice to park the car out where I don't have to do any careful maneuvering with a neon on a 4X4 road, as well as be able to zip around and check out a few remote spots I have been told about.

Gotta love the geode beds and other rockhounding spots Utah has.


l8r

[RM81]

The only replacement parts I have found are other CDI units...


Unless you want to put a dyna2000 on your cb650.
It eliminates the spark units completely.
FOr a week or so I had them in, until I realized the citcuit to them was pretty much inoperable for a couple of reasons.
I'm no electrical whiz, but since the stock timing unit was no longer hooked to the bikes wiring harness, the CDI's never got any signal to fire the coils.
Was checking(or adjusting) something, and realized it.

I immediately took them off, and started her up.
Smiled, and went for a nice long ride realizing that I no longer need those for this bike.
 

l8r

Do you remember which model fit your bike?  There are two different ones listed for a 79 750, but nothing for a 650.

DDK1-5  1979-1983 Honda CB 750, 900, 1100 $399.99
DDK1-5C*  1979-1983 Honda CB 750, 900, 1100  $499.99

How hard was it to install?  Was it just plugging in the new connectors and mounting the box somewhere?

[Soos]

Well, it was the....lemme check...
hrmm... not 100% sure.

The parts wish list I made for that years purchases say it to be a dyddk1-5c kit.
But I cannot for the life of me find the original box for some reason.

There were a few mods needed.
First the timing plate provided is not only 2 small, but it has only 2 and not 3 timing screw releifs on the OD of the timing plate.

Had to graft the dyna pickups onto a old cb650 timing plate.
Not too hard, except getting the bolt hole pattern timed correctly.

Once on there, I had timed something funky(pickup mount bolt pattern in relation to the timing bolt slots) and unfortunately had to lengthen these slots.
Next set I do, I will time it better.(for a more drop in friendly unit)
Lemme tell you the built in timing light on the dyna2000 probably saved my engine.
Different, but it works.
On the dyna2000 unit itself there is a little red timing light.
That, a timing wheel, and a dial indicator to get the TDC of the pistons helped me sort out the timing pretty darned well.



The crank trigger is a REALLY close fit on the stud on the 650's crankshaft.
......Except the pin is on the wrong bolt circle.(and the wrong diameter)

Thats a trick getting that to work. You either need to (precision) bore (I reamed) the pin hole on the correct bolt circle(timed with previous pin hole) and make a stepped pin to fit the new larger hole in the crank trigger, and the cb650 crankshaft.
I might try to scan in my barely legible "prints" one of these days.
A picture is worth 1000 words sometimes.


You could omit the above PITA process....
simply pull the stock pin out, and install the new pin 180 degrees from the old one.
Though you might need to flip the wiring to compensate for the correct timing.(correct firing order and all that fun stuff)

There is a counter bore on the end of the DOHC 750/900/1100 crank trigger so to put the nut above the face I made a aluminum spacer.
to hook up a degree wheel, this is a MUST. Or at least pack enough washers in there for it to work.




I got mine from Z1, at the time it was listed as 379, plus the 79 for the programming software.

http://www.z1enterprises.com/detail.aspx?ID=1980
Looks like they are 379 still.
Great deal considering you get the dyna unit AND a set of coils.



l8r

[Soos]

The only replacement parts I have found are other CDI units...


Unless you want to put a dyna2000 on your cb650.
It eliminates the spark units completely.
FOr a week or so I had them in, until I realized the citcuit to them was pretty much inoperable for a couple of reasons.
I'm no electrical whiz, but since the stock timing unit was no longer hooked to the bikes wiring harness, the CDI's never got any signal to fire the coils.
Was checking(or adjusting) something, and realized it.

I immediately took them off, and started her up.
Smiled, and went for a nice long ride realizing that I no longer need those for this bike.
 

l8r

Do you remember which model fit your bike?  There are two different ones listed for a 79 750, but nothing for a 650.

DDK1-5  1979-1983 Honda CB 750, 900, 1100 $399.99
DDK1-5C*  1979-1983 Honda CB 750, 900, 1100  $499.99

How hard was it to install?  Was it just plugging in the new connectors and mounting the box somewhere?

I guess it would be the ddK1-5C, as mine came with the 2.2 ohm coils.
the ddK1-5 (on dynomans site) shown no coils with it, but the ddK1-5C has the coils.

But I got mine through Z1, and his kit WITH coils was 379...



l8r

[RM81]

Thanks for the info Soos.  That might be a bit more than I'm capable of at this point.  I guess I'm stuck looking for the replacement CDI's for now.

[Hush]

Cool story so far Soos, some of it I barely understand and a lot of it goes "woosh" over my head but hey I see where you are aimimg for.

[verage22]

My dad and I are just starting to restore a 1979 CB650.  It is actually not in bad shape to begin with.  The previous owner said that his son ran it dry on oil! It does have a faint chatter and we are gonna start pulling the engine tomorrow.  I found a piston ring kit from honda for $178, but I cannot find the pistons from anyone.  Any ideas on where to get pistons and a new cylinder head if needed?  Externally the bike is in great shape the paint is still very good.  Need new turn signals found them and found slip on mufflers for it!  Anyways very excited to start this project and hope I can find pistons!!!

[Soos]

Good luck on the new pistons!!

IF you have bad pistons I do have a couple sets laying around in fair to good condition.
As far as heads... there are a few to be had on E-bay from time to time, as well as members here selling them occasionally.

If only a faint clatter, it may be nothing more than the "norm" for these 650's.
Mine "clatters" until it's warmed up... But I guess it depends on your and my definition of "clatter" sounds coming from the engine.

If it quietens down after 15 minuites of riding then it might be ok.

Before pulling the head, pull off the oil pan on the bottom and look and see what sludge is there.
If little/nothing your motor should be fine.
With a good layer(1/8 inch or thicker) with no metal particulates I would at least inspect the cam. If that looks good I would probably run it.
If you find metal shavings.... well thats a definate candidate for a full inspection.(cam, head, pistons, cylinders)
Possibly a new motor at that point, depends on damage.


A much faster way (and more accurate) than going on the P.O.'s story.
Yeah it might have been run out of oil...
but how long, how far?
1 minuite?
1 week?
Who knows.



But if you just wanna tear into it(for experience, curiosity) just make sure you got a manual at least.
helps a LOT... Just look where a manual some curiousity, a bit of ingenuity (and a lot of help here!!) has gotten me...

Overall I'm now(not including comsumables, tires, chain/sprockets) about 1200+ past what it took to get it road legal.
Keeps getting cheaper though.
Seriously thinking of parting out the stock bits I have replaced....




l8r

[verage22]

 Thanks for the info, I got some good news today.  I took the engine apart and took it to a local shop that works on these old bikes and had the cylinders and pistons checked.  They are within spec!!!!  Can't believe it.  The slight chatter I heard I was told was coming from my cam chain.  It needs replaced!  Not a big deal.  The cam itself was also in spec showing only little wear.  big sigh of relief!  So I am getting away with a valve job and carb rebuild.  I did get a manual and found its pretty self explanatory so far.  I am a deisel mechanic just never messed around with anything gas before.  So far so good.  I do need a coil my one is cracked.  I probably wouldn't even sink money into the bike but the frame and painted parts are in excellent shape so I think its worth it!!!  I just love these old bikes!!!  By the way I did find pistons and just about everything else for this bike at this website   http://hondaparts-direct.com/default.asp   nothings cheap but its all new stuff.  I was thinking about buying a new exhaust from MAC should I put the pipes on before I get the carbs tuned?  I would think a little adjustment would be necessary.

[verage22]

I almost forgot.  I found a set of carbs for an 83 nighthawk 650 already cleaned and rebuilt for $115.  My mechanic told me mine will cost 50-100 for each.  Will that set match up to my 79 cb650

[scunny]

the nighthawk carbs will be Cv so the spacing is different, you need slider carbs 79/80