Author Topic: CB650SC Untitled Project: Updated 5/6/2011  (Read 5380 times)

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Offline jkidd01

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CB650SC Untitled Project: Updated 5/6/2011
« on: May 27, 2010, 09:40:23 PM »
Finally after weeks of waiting I got my bike back. Well as of now she no longer runs... battery seems to be low on fluid and has possible erosion spots on it, so I'm buying a new battery before continuing on.

The clutch arm seems to be stuck in place, but not rusted. Either way I'm going to spray some WD-40 on it and try to get it moving again.

Speaking of the clutch, seems like I need a special socket to take out of the clutch... anyone around Grand Rapids, MI got one of these sockets laying around I can borrow? The Honda part number on it is (07716-0020202).

When I turned the bike on (the battery could get up to about 40% give or take life before it stopped accepting me charging it) the rear turn signals didn't come on and the brake light was very dim. When I pressed the start button it made a single thump and didn't make any of the familiar starter noises for me. I hope thats just part of a low/bad battery.

Once I get access to a camera I'm going to start taking some photographic evidence.


As far as plans for the project, I want to keep it looking stock, but not working stock. I want to clean it up, put a new exhaust on it, make new side panels since they are impossible to find on ebay, paint, give it EFI, and build a new gauge set from scratch including new sensors (fuel level, engine oil temp, air/fuel ratio) and build a trip computer into it as well. It's pretty ambitious considering I'm not really used to working with engines. I'm more of a computer and robotics kind of guy.

I'll post an update after I get and install the new battery.
« Last Edit: May 06, 2011, 08:13:49 AM by jkidd01 »
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #1 on: May 28, 2010, 04:11:25 AM »
Well after a short nap I've continued a bit. I want to get the bike back into rideable condition in the next week, so I can work on only the little things during the summer and save all the hard tear apart stuff for the winter.

Got the new battery in, and it has almost no charge, so it'll spend the day charging. But I noticed a funny thing when I went to check the color of my oil. There was no oil in the oil pan anymore. Now I'm positive that it had oil in it before I shipped it, since I was driving it up until only a few days before. And the shipping guy said nothing about draining my fluids out (theres still gas in the tank anyway). So I have no clue where the oil is going, since it's not leaking oil (before shipping at least), and it wasn't burning oil either.

Oh well, the good news is I was going to drain the oil anyway to put the new clutch in, so that saved me a step I guess. WD-40 didn't get the clutch lever to budge at all, so I'll have to disassemble and clean it when I get the cover off.

I've also got adjusting the carbs properly on my list of things to do today. Although I don't for the life of me know what I'm doing in that regard. The only repair manual even close to the nighthawk I could find had pictures of a different set of carbs in it, so I have no idea which screws do what, and most importantly which ones control the idle and fast idle.

1982 CB650SC Nighthawk
1981 CB650C

Offline cb650

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Re: CB650SC Untitled Project
« Reply #2 on: May 28, 2010, 05:17:57 AM »
It could be the cable frosen not the lever.   
18 grand and 18 miles dont make you a biker

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #3 on: May 28, 2010, 05:56:11 PM »
It could be the cable frosen not the lever.   

It was, the cable actually snapped while I was removing it, and even detached won't budge. And now that the cable is off everything else moves nice and free.


Tomorrow I'm going to get the socket to remove the clutch and put the new one in, then it's on to adjusting the carbs while I wait until mid next week to get my new clutch cable.
1982 CB650SC Nighthawk
1981 CB650C

Offline cb650

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Re: CB650SC Untitled Project
« Reply #4 on: May 28, 2010, 06:41:58 PM »
I would worry about the charging before the clutch.   
18 grand and 18 miles dont make you a biker

Offline lostinthe202

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Re: CB650SC Untitled Project
« Reply #5 on: May 28, 2010, 07:51:24 PM »
Are you sure you need a new clutch?  What symptoms made you think you needed a new clutch?  If the cable was frozen, perhaps that was your problem.  The clutch plates and friction discs can get stuck together if they sit for too long.  You may find that if you pull the clutch basket out and pull apart everything and clean it all up with brake cleaner that it will all work fine. Inspect the plates and discs if you have the means as well as the clutch basket edges.  They can get grooved which prevents smooth clutch action.

The loss of oil is a bit suspicious.  Are you sure it actually has no oil in it?  Did you remove the drain plug to see if anything came out? 

Will-
'72 CB500

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #6 on: May 29, 2010, 03:52:48 AM »
Are you sure you need a new clutch?  What symptoms made you think you needed a new clutch?  If the cable was frozen, perhaps that was your problem.  The clutch plates and friction discs can get stuck together if they sit for too long.  You may find that if you pull the clutch basket out and pull apart everything and clean it all up with brake cleaner that it will all work fine. Inspect the plates and discs if you have the means as well as the clutch basket edges.  They can get grooved which prevents smooth clutch action.

The loss of oil is a bit suspicious.  Are you sure it actually has no oil in it?  Did you remove the drain plug to see if anything came out? 

Will-

I'm pretty sure I need the new clutch, at the end of last summer I had a Honda dealer change the oil and I guess they noticed that the clutch slipped sometimes and tried to adjust the clutch and eventually looked at the clutch and told me that it had several grooves that were causing the slipping.

I did pull the drain plug out before I dared to pull off the clutch cover, and very little came out... maybe 3-4 oz tops. After getting the clutch case off I found another 1-2 oz inside the case.
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #7 on: May 29, 2010, 08:36:53 PM »
I would worry about the charging before the clutch.  

I agree, but I wanted to get new oil in it before I started it back up and since I drained all the oil already to replace the clutch, and I already had the new clutch, I figured I would just finish replacing that first. Which I finished today.

Shortly after I started it up with the new battery and let it run for a bit. It was charging the battery like it should, so I think the old battery must have had a problem with it or maybe the acid leaked out during shipping.

Also new issue: Once the engine warmed up it stalled out and wouldn't start back up. Any ideas?
« Last Edit: May 29, 2010, 09:05:20 PM by jkidd01 »
1982 CB650SC Nighthawk
1981 CB650C

Offline cb650

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Re: CB650SC Untitled Project
« Reply #8 on: May 30, 2010, 05:40:34 AM »
Did you let it get too hot?     Has the tank been cleaned out?
81/2's had a vacum shut off that should be tossed in the trash.
18 grand and 18 miles dont make you a biker

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #9 on: May 30, 2010, 04:26:54 PM »
Did you let it get too hot?     Has the tank been cleaned out?
81/2's had a vacum shut off that should be tossed in the trash.

It was only running for about 10 minutes before it shut off, so I don't think so. I also tried it again not too long ago, and even cold it won't start now.

I haven't cleaned the tank out no, but I did take a look inside with a flashlight and it looked nice and clean on the inside, and gas flows out of it so I haven't thought about it.

Where is the vacum shut off located?
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #10 on: May 30, 2010, 06:42:11 PM »
Got it running. After cb650 suggested the tank might be dirty I started thinking about the inline fuel filter. I ran a few tests and determined that it was clogged and I replaced that and it started right up and ran fine. Now I just have to adjust the carbs properly.
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #11 on: May 31, 2010, 02:24:37 AM »
Okay, so after looking all over I can't seem to find the idle adjustment. I've been using the repair manual at http://cosky0.tripod.com/ but it doesn't seem like the adjustment is in the same place on the Nighthawk.

Anyone with a Nighthawk or familiar with it know where it is, and maybe can take a picture of it to show me?
1982 CB650SC Nighthawk
1981 CB650C

Offline cb650

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Re: CB650SC Untitled Project
« Reply #12 on: May 31, 2010, 06:01:03 AM »
Should be on the bottom of the carbs just to the left of #3.  The auto shut off is what the fuel line will go to first after the petcock.
Top left side of the carb bank.
18 grand and 18 miles dont make you a biker

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #13 on: May 31, 2010, 02:49:09 PM »
I went looking for it, and still couldn't find it.

Thats where my fuel line was going straight from the tank. That's on the top between 2 and 3, on the airbox side.
But when I looked at diagrams of the automatic fuel valve it doesn't look the same.



My fuel line hookups look nothing like this diagram (pulled from the parts fiche from a honda dealer for the Automatic Fuel Valve part on the 1982 CB650SC). I also noticed an empty screw hole on the underside of the right hand area of Carb #2.
1982 CB650SC Nighthawk
1981 CB650C

Offline cb650

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Re: CB650SC Untitled Project
« Reply #14 on: May 31, 2010, 03:01:13 PM »
Sounds like someone has been messin with the carbs already.    The auto shut off might be gone already.  Make sure they pluged the hole for the vacum.   
18 grand and 18 miles dont make you a biker

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #15 on: May 31, 2010, 03:19:29 PM »
I assume you mean this tube: 

It was cleverly hidden underneath the frame above the carbs. Still has a clamp attached to it, but as long as I've had the bike it's never been plugged into anything.
1982 CB650SC Nighthawk
1981 CB650C

Offline nitroeagle

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Re: CB650SC Untitled Project
« Reply #16 on: May 31, 2010, 07:24:52 PM »
yea, looks like someone took it off. it's easy to spot. the hose from the petcock on the tank goes right to it. i have an '82 cb650, not a "c" though. the carb stuff is the same

Offline cb650

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Re: CB650SC Untitled Project
« Reply #17 on: June 01, 2010, 04:26:24 AM »
If that is the vacum tube make sure its pluged.
18 grand and 18 miles dont make you a biker

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #18 on: June 04, 2010, 10:22:44 PM »
Got it up and running today, new clutch cable installed and everything. Found the idle adjustment too, it was right where everyone said it would be, but the screw on the end was broken off and won't turn under finger pressure and it was broken too high into the carbs to turn with a pair of pliers. So it looks like I'll end up having to pull the carbs out eventually to adjust that.
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #19 on: March 31, 2011, 06:40:07 PM »
Finally got the money and time to get around to starting back up work on my bike.

Here are the current plans:

Do a monoshock conversion using the stock shock and swingarm from a 2008 CBR600RR.
Change the top triple tree to the one from the 1984 Nighthawk.
Do an EFI conversion.
Mount a custom gauge cluster.
Paint it, so it looks good again.

Heres the progress made in the last week:

Got the bike stripped down to the front end and frame today.


Engine on a palet with the new swingarm.


Then we ground a bit out of the frame to allow enough room for the new swingarm. Still have another 1/8" to 3/16" left to grind out for a perfect fit.


Still a ways to go, but a good start. Probably finish up getting the swingarm in tomorrow evening, and lining up the sprockets.
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #20 on: April 05, 2011, 05:21:42 PM »
Looks like we need to take more out of the frame than there is steel. So for now we've drawn lines for cutting out a small section of the frame around the area the swingarm mounts to, and we're going to weld in a solid piece made to the exact width of the swingarm being mounted.

If it weren't for the steel being hollow there would have been plenty of room to grind out...

Anyway, tomorrow morning will see me pulling off the front end completely to fit the new triple tree.

Speaking of which, where is a good place to get a single wheel from? I'm planning on replacing the front wheel with either an 18 or a 17 instead of the stock 19, but I don't want to pay more than say $2-300 for it. The only places I was running into on the internet were RC Components and they want something like $1k per wheel.
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #21 on: April 08, 2011, 01:52:55 PM »
Took the forks off yesterday and got everything disassembled. Tried to grind the last 1/16th inch out of the frame when... I discovered that I had ground too far into the frame and now I need a new piece of steel welded into place.

Since fabricating and welding steel are way above my head, not to mention I don't own any of the equipment, I took the frame to a power sports customization shop. Now, I just hope my little screw up doesn't cost me too much more.

Here's the damage.


The guy from D3Customs said it would only take about a week for him to repair my screwup so, hopefully in about a week I'll be back on track with the bike.

In the meantime, I'm going to line up the fuel injectors with the engine and make sure the spacing is correct, and modify or order any parts I'll need.

On the good side though, I found another '82 Nighthawk around that has the original exhaust in very good shape, although the bike itself is pretty much junk, but nevertheless it's got some spare parts, so I won't have to be as afraid to screw things up anymore. I'll post a couple pics of it once I get it home early next week.
1982 CB650SC Nighthawk
1981 CB650C

Offline jkidd01

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Re: CB650SC Untitled Project
« Reply #22 on: May 06, 2011, 08:13:06 AM »
Well, picked the frame up today from D3 Customs, with my new swingarm and shock linkage mounted. They fixed everything I screwed up and lined everything up properly for a chain.

Here's a few pics of it all.

The left side view with the swingarm mounted and back tire on.


Close up of the left side.


Close up of the right side, this is where they repaired the damage from me trying to mount this myself.


Here's the linkage for the shock, I wanted to keep the stock styling for the swingarm and shock that the 2008 CBR600RR has.
1982 CB650SC Nighthawk
1981 CB650C