The Humpty Bike - Putting it back together again

[CopperCollar]

Probably do not want to hear this but I would pull the motor apart. If those rods are rusted over there is a good chance the transmission is as well along with the needle and roller bearings. With the big six it's well worth doing right . It will add more to the bill but the payoff is worth it.

Besides, shot peening the rods adds some benefit. I am sure Preston can fill you in on more than I can.

Once done you will really come to enjoy the sound of the engine.

Not to worry, I had my chance to stay on the island's. I really appreciated the weather and the diving.

Mike

[Rick Pope]

The drag racer over there is Jon Bratten. I don't remember which island he's on.

[spencer]

The drag racer over there is Jon Bratten. I don't remember which island he's on.

Honolulu, Oahu

[NobleHops]

The drag racer over there is Jon Bratten. I don't remember which island he's on.

Honolulu, Oahu

I was just there and met a guy that used to race. The racetrack got shut down on some or other pretext of development of the area and that of course stalled. No more racing on Oahu.

N.

[EMS]

here are some other answers:

-The suspension front and rear is an "air support" design. It basically has pressurized air above the oil. It is not tied into the ignition, it is "manual", which means you will have to maintain the pressure by pumping it into the front forks and the rear shocks. Nothing will "rise" when you turn the bike on. Only thing is, your rear suspension warning light on the instrument panel will light up when you ride faster than 15 mph and the pressure is low.
- on the Prolink models (and on the 1980, for that matter) no parts are magnesium anymore. Only on the 1979 model several covers on the motor were magnesium.
- The saddlebags are a reasonable valuable item and if in good condition, should be an easy sell. Either here or on ebay. Most people may change the locks anyway to match them to their keys.

Keep up the good work and these questions coming. Try to find John Bratten. He had an '81 also, I 'm pretty sure.

[kauai1800]

Thanks for all this info guys. I'll ask around about Jon Bratten - maybe he comes over to the drag races we have here. I saw a guy named CBXroger on the forum member list who was from either Oahu or Maui...he posted here a lot and then stopped a couple years back.

Also I'm gonna try to find someone here on Kauai who can help me.
I'm still reading a lot and watching videos. Gonna read the whole shop manual.
Is there an '81 parts list as a PDF somewhere? My old xeroxes are a bit hard to read.

I saw the videos by bikeymikey and Aris on Youtube - very useful stuff - thanks guys!

Also I surmise that a really cool CBX book came out and then rapidly sold out and now the only way to get one is to watch eBay..?

I'm going to put the saddlebags and racks up on eBay - I've got a couple other random things to sell there anyway.

I'd love to have this bike back on the road for under $1500 total - so by selling off unwanted parts I can raise funds to be used towards buying new parts or having service done. If anyone is familiar with the Grassroots Motorsports Challenge...something like that. My wife really hates me having more than one bike - she was swayed only by the extreme low cost of this project (and my puppy dog eyes).

Where I live the ethic is a bit different than some places I've been. Here it's "cooler" to have something that you saved from the junkyard than it is to have something new. A shiny new 5-Series BMW is an embarrassment here; but a 1978 Datsun pickup truck painted primer gray that still runs is cool. That's the same philosophy I'll be applying to this build.

[tevan]

Thanks for all this info guys. I'll ask around about Jon Bratten - maybe he comes over to the drag races we have here. I saw a guy named CBXroger on the forum member list who was from either Oahu or Maui...he posted here a lot and then stopped a couple years back.

Also I'm gonna try to find someone here on Kauai who can help me.
I'm still reading a lot and watching videos. Gonna read the whole shop manual.
Is there an '81 parts list as a PDF somewhere? My old xeroxes are a bit hard to read.

I saw the videos by bikeymikey and Aris on Youtube - very useful stuff - thanks guys!

Also I surmise that a really cool CBX book came out and then rapidly sold out and now the only way to get one is to watch eBay..?

I'm going to put the saddlebags and racks up on eBay - I've got a couple other random things to sell there anyway.

I'd love to have this bike back on the road for under $1500 total - so by selling off unwanted parts I can raise funds to be used towards buying new parts or having service done. If anyone is familiar with the Grassroots Motorsports Challenge...something like that. My wife really hates me having more than one bike - she was swayed only by the extreme low cost of this project (and my puppy dog eyes).

Where I live the ethic is a bit different than some places I've been. Here it's "cooler" to have something that you saved from the junkyard than it is to have something new. A shiny new 5-Series BMW is an embarrassment here; but a 1978 Datsun pickup truck painted primer gray that still runs is cool. That's the same philosophy I'll be applying to this build.

As far as the PDF parts list go to the CBX WORLD website and look under "CBX Technical". I think that should help you out.

[kauai1800]

Thanks tevan! I will check that out straight away.

As I'm assessing things - I'd like to ask for opinions.

Here's the front rotor - it has no grooves nor wear, just this surface rust. I know these are stainless steel but here in Hawaii there is no such thing!


Here's the rear:


The "grooves" you see are an artifact of the light. They are less than .1mm deep.

All 3 calipers look pretty beat up and rusty too - they would need to be rebuilt. (no photo at the moment). The pads are brand new though!

Your opinion as to whether I should:
1) rebuild the calipers and send the rotors out to truedisk for resurfacing. The rotors are still OEM spec aside from the rust pits.
2) Rebuild the calipers and just remove as much rust as I can and not resurface the rotors.
3) do the conversion to GL1000 brakes all around.

Thanks & Cheers! -John

[NobleHops]

My opinion: In the interest of economy I'd do the rebuild of the calipers and master cylinder, consider new lines, and send the disks to TrueDisk. I'd also consider going to a two-line steel setup and ditching the splitter on the fork. It's less stock but it will be tons easier to bleed and perform better. You must do the masters, and possibly replace that white reservoir on the front.

ALL THAT SAID. You could buy a ball hone, chuck it up in a drill press and do a totally good job of honing these yourself if they are 6 mile rotors.

On another front, can you use these?



Sadly I do not have the colletts that you need - there are two-piece flanges that these bear on and those in turn bear on the lip of the header pipes. You'll need to scare those up if you don't have them. Louis Mintrone from UsedCBXParts.com is a great source for used and NOS parts large and small.

PM me your mailing address and I'll get these on their way to you tomorrow, and give you a good karma bump.

N.

[kauai1800]

Many thanks Nils! PM sent!
Karmic score increased!

Also I "met" Louis online today - I see he's the man for getting parts.

And I do have a drill press and those ball hones look cool. Looks like it can also be used to make the cylinder bores looks all happy again too. I'll have to find a thread about using it for rotors. Cheerios!

[CopperCollar]

I may have a set of rotors in my stash. Yours look pretty rusty between the disc surfaces. Bead blasting may clean that but the pitting might be deeper than they can machine out.

Might have a set off adjusters that are not rusty.

When I get off work I will look.

Not sure what postage is to the islands.

We can work that out.

Mike

[kauai1800]

Many thanks for that generous offer Mike! I'll shoot you a PM later on today.

Did some rust-busting on the stock pipes and they are looking much better! Here's a before vs an after...

[NobleHops]

Many thanks for that generous offer Mike! I'll shoot you a PM later on today.

Did some rust-busting on the stock pipes and they are looking much better! Here's a before vs an after...

Wow, OK, that's encouraging!

I have concerns about your rotors too. Do you have a blasting setup you could use for the non-disk surfaces? You can get a cheapo HF setup for glass bead or powder blasting and get rid of that interior rust, then paint, if Mike can't hook you up.

N.

[steve murdoch icoa #5322]

Bare feet at this time of year is just plain annoying!

[bikeymikey748]

Did some rust-busting on the stock pipes and they are looking much better! Here's a before vs an after...

Not to rain on your parade,but...they ( the pipes ) look great, just now, but as the corrosion that you removed extended beyond the chrome plating, the bare metal is now exposed to mercy of the atmosphere.....with predictable results.

Probably do not want to hear this but I would pull the motor apart. If those rods are rusted over there is a good chance the transmission is as well along with the needle and roller bearings. With the big six it's well worth doing right . It will add more to the bill but the payoff is worth it

I'm with Mike on this too. I realize that you're trying to bring this home on a budget. But, you'd really hate yourself if it came to doing the job over a second time ( God forbid ) shortly after buttoning things up