'79 Custom - staying custom...for now (10 year sleeper)

Hey, what projects are you planning or preparing for? CBX, other motos, workshop, WHATEVAH!
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desertrefugee
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'79 Custom - staying custom...for now (10 year sleeper)

Post by desertrefugee »

I did my intro this past weekend. For continuity and reference, it can be found here along with a couple of early photos:

viewtopic.php?f=108&t=10961

A quick recap:
- One owner, but messed with over the years - nowhere near original
- Hasn't run in 10 years. Supposedly had Stabil in tank. Gas stunk and was orange.
- VERY nice flame job on tank
- Motor painted black, needs to be redone
- RC Engineering headers (need chrome or ceramic) - have the cans never installed
- Sport kit
- Corbin seat

So, I've spent some time bonding with this bike. Cleaning off 10 years of mainly dust. Of course there's some sludge on the chain side as it ran without a guard for who knows how long. As an Arizona bike that was always garaged, it is very well preserved. Here's the only rust I found on the bike:
IMG_5734.JPG
I've drained the tank and find it pristine inside. Petcock leaks like a sieve. I've ordered a kit and will be drilling rivets soon. I've also drained the crankcase will will refill it soonish. I have no illusion about the need to pull the rack and go through the carbs - but for now I do have one main question:

Initially, I'm trying to keep costs down (another simultaneous project) and wonder what potential drawbacks there would be in seeing if I can get it to fire off before going further? I'd really like to hear how the motor sounds before I go off and tend to other things. Things that might be far less interesting if there are ominous noises coming from the bottom end, for instance. If it sounds decent, I'll feel a lot better about worrying about other stuff initially. I'm not into the bike that deeply and would love to keep it that way.

So, carb sludge won't get any worse by firing it up. I'd just like to try and get it warmed up and up on the mains to hear how she runs. Then, it'll be time to tilt that six forward.

Any reason not to do that?
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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by Rick Pope »

I could be wrong, but I believe you won't get it running on the main jets without riding it. It will over rev long before it gets there. Besides, it's the idle circuits that cause most of the issues.

Hopefully, one of the real carb folks will come by with facts.
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Either garage is too small or we have too many bikes. Or Momma's car needs to go outside.

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by daves79x »

I'd can't think of any real damage you can do by trying to start it, unless it's been fiddled with since it last ran - every new CBX owner wants to do that. But if your goal is to evaluate engine health by hearing it run - you will be mightily disappointed. Running a CBX with dirty carbs will result in the engine sounding like a diesel. Valves will clatter and the clutch will sound like it's coming apart. It likely will not be a useful exercise, other than for you to hear it actually run.

I'll post for you a checklist of things a bike that's been sitting a long time should have done/checked. You asked about that a couple of days ago. Just give me a bit.

Dave

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by daves79x »

Got a minute now, so here are some things you should check/do with a CBX that's been sitting for years, before starting it up. I've re-commissioned many such CBXs over the years and these steps have served me well:

A thorough cleaning/degreasing. This alone may reveal problems not evident upon first inspection.

Get a Honda shop manual.

Tilt the engine, remove the carbs. They will need a complete rebuild, including complete separation and new rubber parts. This is the most critical part of making a CBX run correctly. No shortcuts here.

Install new intake rubbers, and a stock air filter, either stock foam or later paper one.

Clean what you didn't get before the engine was tilted.

Carefully blow out all debris in the head and remove spark plugs - you'll be replacing them and use only NGK.

Remove valve cover and check the valve clearances - nothing under .003 inch. Adjust cam chains the correct way, where you can see what they are doing. Carefully inspect the front cam chain adjusting bolt - remove it and be sure it hasn't been replaced with a generic one, and install a new o-ring on the bolt threads. It likely has already been Heli-coiled. Look over the top end, cam cap orientation and numbering and cam cap bolts. Any miss-matched bolts, odd other fasteners need carefully evaluated and corrected. Install all new cam cover hold-down bolt grommets. Your valve cover gasket is likely OK to re-use, but figure on spending a lot of time cleaning it and the cover in preparation for re-installation, per the manual. You can check compression now if you want, but a check after it's been run through several heat/cool cycles is more meaningful. As long as they are close, anything over 120 psi is OK. RE-check valve clearances after a couple of hundred miles, as well as oil and filter and dropping the sump again. If all's clean there, you'll be good to go. I know, it's a PITA, but necessary.

Remove the right crank cover and be sure the o-ring is on the top screw, or in the hole - if not, get an new one, and for the left side as well. New gaskets too. Remove the pulser cover. Remove the pulse unit and the advancer. Clean and re-lube the advancer and be sure it moves freely. Re-install everything and set static timing.

Remove the sump cover and inspect the debris found there. Clean and replace. Install new Honda oil filter. Use Honda 10W40 non-synthetic oil.

Remove the starter, disassemble and clean. Reinstall, making sure all connections, including the block ground wire, are tight. While you're at that, take apart and clean all wire connectors under the right side cover. Note carefully the red alternator connector - it may be slightly melted. It will need replaced if so. If the bike still has the stock 30 amp main strip fuse, replace it with a new one - they get old and disintegrate. Or replace the whole thing with a modern blade fuse. Take apart each spark plug cap/wire. Inspect for corrosion, then screw the caps back on TIGHTLY.

While you have the alternator connector apart - just remove the whole alternator and completely disassemble it. Check every component, replace the bearings and seal and install new brushes. Measure the spring and inspect the clutch surfaces. Volumes written here about alternator service.

Throw away the lead-acid battery if it has one and get an AGM.

That about covers just the engine checks.

Chassis-wise, figure on a complete front and rear master cylinder and caliper rebuild. No shortcuts here either. Replace any not-to-spec components, likely caliper pistons /rubber parts, brake lines, master cylinder kits, front cup, etc. These things actually have very good brakes is they are serviced correctly. If the front forks have been leaking, figure on replacing the front brake pads too, they will have been soaked with fork oil and will be junk.

Rebuild the front forks, leaking or not. New seals and proper fork oil, set to proper height. Again look that up here. Figure on complete triple tree disassembly and new steering bearings also. Check the wheel bearings, these are pretty robust and rarely need changed.

Remove the swingarm and see what bushings are in the pivot. Replace with bronze if still original plastic.

Replace tires immediately with modern rubber of the correct size and of your choice.

Check and clean all wire connectors in the headlight shell and the handlebar switches. Install all-new bulbs for at least the headlight, tail light and turn signals.

Clean out the fuel tank completely and rebuild the petcock - it WILL leak.

Many gaskets, seals, and wear parts are still available from Honda. Those things, as well as all the NLA stuff, are available from the many vendors supported here: TIMS CBX, Louis Mintrone, JR Luksik, CBX Performance International, David Silver Spares USA, Mike Nixon, and overseas from Six Center and others.

Only after attending to these things can you assure yourself of having a CBX that is functioning the way Honda intended and to avoid endless problems down the road. You WILL be addressing all these things, either now or one at a time, when you might least want to.

Let me know if you need some specific suggestions about your carbs.

Hope this helps.

Dave

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by desertrefugee »

Mother McKree and General Jackson!

First, huge thanks for posting this list, Dave. If it isn't already, it should be "sticky'd" and available for any and everybody in a technical archive around here somewhere.

But, holy smokes that's an extensive list! I'll be honest with you, I had a lot on deck that I had planned to do, but I sure didn't include many of the things you have noted. Heck, I wouldn't even have thought of some of them – like starter, alternator and pulsars for instance.

So, I will begin moving through many if not most of the items noted. But it won't be a quick project. The dog days of summer in southern Arizona will be here soon and I don't tend to spend much time in the garage when it gets near and over 100. That's a good time for stockpiling parts and/or working on removable items that can be brought inside. For now, I'm trying to make as much progress as I can before then and think I'm doing fairly well.

Thanks again for that comprehensive and very valuable checklist. That is exactly what I was hoping to find – especially the items the specific to the CBX.
'86 VMax, ‘83 ZN1300-6, ‘78 GL1000, '75 750K

"The older I get, the more I understand. Don't let the fear of what could happen make nothing happen." - Anonymous

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by FalldownPhil »

Great write up Dave !!
I agree that it should be a sticky.
On another note, I may be starting one up today that has been sitting for at least 30 years, probably longer
as it has unbelievably low mileage. It has been quite a project :-)
Best,
Phil
When you are up to your ass in alligators it is sometimes difficult
to remember that your objective was to drain the swamp !!

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by wyly »

absolutely dave's checklist should be a sticky ...invaluable info !
CBX a work in progress, still improving...GS1150EFE completed and awaiting modifications.....RD350, remnants in boxes scattered throughout the garage

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by solarmoose »

Dave,
Thank you! Very useful and methodical list. Will be using this to restart '79 that has had a long sleep. I can concur re digging in deeper to see what is not right and/or poor repairs. Those things can only be found by taking covers off, inspecting and fixing before startup and possible catastrophe. I have learned that the hard way. (i.e. Loose bolts attaching cam gear to cam.) We just don't know what has been touched by PO and there's a limit to what can be learned by even a comprehensive visual external inspection.
david

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by wyly »

Even when a it’s supposedly worked on a pro you should check...when my engine was torn down after it’s implosion I found loose cam clamp holder bolts, one only stayed in place because the cam cover held it in place...
CBX a work in progress, still improving...GS1150EFE completed and awaiting modifications.....RD350, remnants in boxes scattered throughout the garage

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by desertrefugee »

I am really hoping that this motor (22k) has some good life left in it. Looking at prices for engine components I see that a rebuild done right would be rather expensive. I hope to defer that cost as far out as I can.

I have the tank sorted out now with the rebuilt factory petcock and solvent running clear. But I don't think I'm going to keep the OEM petcock. I believe I will just go with the Pingel. I don't trust my rebuild.

Pulled the battery box to address igniters that had begun to offload their encapsulant. Managed to do a bit of detail work under there a while at it.

Carb kits are due in tomorrow along with Mike Nixon's golden overview of the intricacies of the process.

Much more to come - especially within the context of Dave's list above!
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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by wyly »

desertrefugee wrote:
I have the tank sorted out now with the rebuilt factory petcock and solvent running clear. But I don't think I'm going to keep the OEM petcock. I believe I will just go with the Pingel. I don't trust my rebuild.
Pingel is an excellent choice...and if you haven't heard the true horror stories about rods through the crankcase on 79's, just don't forget to always turn off the petcock and park it on the center stand...
CBX a work in progress, still improving...GS1150EFE completed and awaiting modifications.....RD350, remnants in boxes scattered throughout the garage

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by desertrefugee »

Really starting to get after it now. Racing the clock to cover some ground before it gets too hot in the garage...
IMG_5787.JPG
IMG_5786.JPG
IMG_5764.JPG
IMG_5742.JPG
More to come.
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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by daves79x »

I don’t think we discussed the pod filters. You should find much larger than stock jets in the carbs, roughly 80 and 120 if the P.O. used Keihin jets and stock needles. More likely you’ll find a Dynojet Stage 3 kit with adjustable needles and dynojet’s own jets. Not the best set-up either way, but see what you find and give me a shout. I’ll try to walk you through the best compromise.

Dave

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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by desertrefugee »

Thanks again Dave. Really appreciate the resource!

I already know there's a Dynajet kit in there. I also know the bike was running rich on all six. Plugs were carboned up pretty good.

Nixon's booklet also mentions that you DON'T want to find Dyna bits. Dang, and I was kinda happy when the old guy told me he'd had them installed.

I'll let you know. Headed over to borrow a buddy's ultrasound cleaner this afternoon. May start on them tomorrow. I couldn't wait to get a sneak preview.

Could have been worse...
image.jpeg
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Re: '79 Custom - staying custom...for now (10 year sleeper)

Post by desertrefugee »

Overhauling these carbs, I've run into a snag. Doing a preliminary synch on the right side bank, I have found that the synch screw between carbs 5 and 6 is hitting the aircut passage pipe. That screw is ALL THE WAY OUT and the throttle plate on #6 still isn't fully closed. The synch connection between 5 and 6 appears OK. I cannot see what I've screwed up. Has anyone run into this? Thanks in advance from a CBX rookie.
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