Author Topic: That Little Dolphin's Got Fire In Its Belly! (CM400)  (Read 20445 times)

Offline dcwp

  • Posts: 559
That Little Dolphin's Got Fire In Its Belly! (CM400)
« on: Jul 31, 2009, 10:24:37 »

I've been reading all of your builds for a while and I'm finally ready to start my own.  For me, this will truly be a big arse project, but compared to what you all are up to, I think maybe it's better to call it a medium arse project.  I realize that sounds an awful lot like 'half ass' but hopefully there will be a difference.

The bike is a 1981 Honda CM400T.  The T in the model number stands for tachometer, but I think it should really stand for "trainer" since this will be the first project big project I've taken on. 

I'll attach a picture of what this bike looked like when it was running before I got it.  Not too bad in that 1980s sort of way, but kind of goofy with all those big curving, swooping lines.  Anyway, my friend who had it when it looked that good ran on a rusted out tank for too long and eventually the head got too crudified and lost compression.  So I used it as a parts bike for my daily rider, which is looking pretty good now that it's got all that shiny chrome, new tires, etc.  Because of the shape and color, I've been calling it the Parts Dolphin. 

I've spent the better part of this summer rebuilding the top end of the bike, I tore the head down, cleaned the crap out of it, new seals, lapped all the valves and seats, etc.  The head had little nodules of rust and carbon jammed into the valve seats holding them open around 1/16-1/8".  No wonder there was no compression!  I also re-rebuilt the carbs.  I tried to rebuild them when I got the bike, but used Simple Green and didn't rinse it off so they corroded to the point that the butterfly valves and sliders wouldn't budge.

So last night I finally got everything put back together.  I hooked up the battery and tank from my other bike, gave a few pulls on the starter and miracle of miracles there was fire in the belly!  The carbs still need a tiny bit of adjustment to get the bike idling on its own, but it's alive.

So now I have a running bike with a rusted out gas tank and missing all its shiny bits as they were cannibalized for my other bike.  I have wanted to do a cafe bike since I got these monsters, but the goofy swooping frame will make it difficult.  Now I'm thinking that i may do something more brattish.  Sort of a hybrid, not really sure yet. 

I'm really impressed with Roustabout's brat build and I think something like this might be doable with my materials and skills. 

Anyway, where this gets interesting/scary is here: 
*I have only been riding motorcycles for about two years and working on them for three
*I don't have any formal training in mechanics, body work, or really anything else related
*I don't have access to welding, painting, or other specialty equipment without simply hiring it out
*I don't actually know anybody within about 700 miles who does any of these things
*I don't even know anyone else in the state who rides a motorcycle

*I've always been mechanically inclined and good with cars, tractors, mountain bikes, etc
*I'm too stupid to not just jump into things that are over my head
*I'm not too shy to ask dumb questions
*I did work in an electrical shop in college so I'm comfortable with wiring

So I'm planning to use this as an opportunity to learn what I need to know.  For now I won't be doing a full overhaul - no painting or welding frame.  I'll be getting the bike back into street-worthy condition, going for light weight and performance where I replace parts, and doing a general cosmetic overhaul.  If I like the bike I come up with, then next year maybe I'll strip it all down and start from the ground up, refining as I go.  I'd like to maybe even take some classes in welding or body work in the mean time, but I'm finishing a doctoral dissertation, teaching full time, and trying to stay married so this will all have to happen as time/budget allows.

So what say ye?  Too ambitious?  Too cautious?  Specific ideas for getting this bike running and looking sweet?

edit: D'oh!  Left my camera at home with all the current pics.  Will post the carnage tonight, first here is the bike when it was a daily rider.

Offline dcwp

  • Posts: 559
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #1 on: Aug 04, 2009, 23:46:48 »
Alright, as promised I'll start posting some pictures.

Here's what the bike looked like the first time I got it to start

Pretty fugly, eh?  The real ugliness was in here

Hard to see in this pic, but the valve seats are totally crudded up.  Luckily not pitted, but covered with little nodules that are like pearls of carbon accumulated around rust flakes.  No wonder the engine had no compression at all.

Since I got the engine back together and the bike running, I'm spending my time tearing the rest of the bike apart.  Got the front end mostly disassembled and started painting.  Here's a shot of the bike in the process of losing its front end.  I like this pic because I think it looks like a mutant lovechild of the predator and a robotic bug.

I'm not planning to take the motor out and paint/powder the frame for now, so I want to get it stripped down most of the way and give it a good scrub.  Lots of dust, grime, and spiders hiding out in there. 

I've started cleaning, stripping, and priming the rotor, calliper, and various other bits I've pulled off and I think I've decided on a color scheme.  I'll be doing Brittish Racing Green on the tank, headlight mounting ears, and possibly shock coils with a dark gold for the interior of the rotor, the calliper, and maybe one or two other trim areas. 

The real fun comes tomorrow.  I have to take my wife to visit a friend two hours away.  It just so happens that the best bike bone yard in the state is in the same town.   :D  I'll be slipping away for a couple of hours to see what treasures I can find and I'm especially on the lookout for a useable tank.  Will report back.

Offline Ghosttown

  • Posts: 158
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #2 on: Aug 05, 2009, 11:29:33 »
Just the name of the thread is great, I can't wait to see more! I also have an 81' CM400e that is in need of an overhaul..... someday.
« Last Edit: Aug 05, 2009, 11:31:20 by Ghosttown »
Bag O' Corn, Friend!

Offline dcwp

  • Posts: 559
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #3 on: Aug 06, 2009, 23:15:13 »
Thanks Ghosttown.  I'll look forward to seeing what you do with yours.

Meanwhile I keep tearing things down.  My daily rider was dropped at some point before I got it, so I switched off most of the trim pieces, and now those are what I'm dealing with.

One of the headlight ears is pretty munged, but I got it more or less straight.  Now cleaning rust.  If I can't get it clean enough, I'll paint it black

The headlight bucket is even worse

I thought about gluing it, but I think I'll just try to find a new one.  Should be cheap enough.

Lots more carnage (the shift lever may not be salvageable), but I'll spare you the nightmares.  Some things are starting to come together.

Finally started priming some pieces.  I'm doing dark gold engine enamel on the interior of the rotor and the exhaust clamps.  The engine primer calls for a full week of curing so I should have some pics of the final color early next week

There are my header pipes too.  I think maybe I should have done gloss instead of matte, but I plan to wrap them eventually so I'll leave the matte for now.

I was going to paint the wheels, but I cleaned them up and used some of that colorMagic wax and they look pretty good so I'm going to leave them.  Will need new rubber soon.

Right now I'm painting the caliper, polishing the master cylinder (off a CB somethinerother), and trying to figure out what to do with these

I wanted to take them apart and paint the coils and polish the tubes, but I haven't been able to get them apart.  The guy at the local bike shop looked at them and told me they couldn't be taken apart and should be thrown away because there is rust  :-\  I'm pretty new to motorcycles, so he might be right.  But I'm suspicious because after talking to him I walked around to the parts counter to get a price on new shocks and the guy there (who I know also works on vintage bikes) said, "you should just take those apart and clean off the surface rust."  He seemed pretty sure it was possible.  Anyway, maybe I'll just hit them with a brush and some Mothers polish and see if that helps.

Tomorrow off to a new junkyard, still searching for a tank.

Offline Maritime

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  • Posts: 9868
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #4 on: Aug 07, 2009, 09:19:12 »
The shocks come apart. I know.  I did mine.  A spring compressor would help, but I couldn't find one that would work so here is what I did.  There is a lock nut under the top eye, put a wrench through the coil to hold it, then put a socket extension in the eye hole and unscrew the top from the shaft.  The shock spring isn't that strong at full extension,  once the top is off the bodies can be cleaned up and springs etc.  Getting them back together is a little harder without a spring comperessor but I just used my body weight and some muscle to get the springs compressed enough to start the threads on the tops, once started hold the nut and screw down the shock tops until tight. 


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Offline dcwp

  • Posts: 559
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #5 on: Aug 10, 2009, 11:53:38 »
Thanks for the tip Maritime Biker.  I messed with them a little and managed to get a wrench in there, I see what you're talking about.  For not though, I've decided to leave them together.  I think working on the bike in sections will help me stay organized and not overwhelmed.  Everything else I'm doing right now is on the front so I'll get to the shocks when I'm at the back of the bike.  I may just end up swapping with my daily rider, it's got very clean chrome shocks.

Anyway, I spent the weekend cleaning shiny bits and finally have some color.  I'm not super thrilled with how the colors are coming out though.

First is the green.  I painted my headlight ears because the chrome was pretty bad after getting them straightened.  I'm also planning to paint the tank this color.

I was hoping this would be a little darker, but I really like this shade.  Plus it's got more sparkles/metal flake/whatever that stuff is than I expected.  That's definitely good.  Hard to see in this pics, here's one in the sun.

I'm happy with that color, but the trim color is less good.  I wanted a dark gold or bronze color, but since I needed VHT or engine ename, my options were limited.  The gold is a bit more bright and, well, gold for my tastes:

Maybe it'll grow on me, it goes fairly well with the green:

I'm still planning to paint the caliper that same gold color, but the primer wants a couple more days to cure.  I may or may not decide on another color in that time, but I don't think I've got many options

Got a lead on a tank.  If the guy will ever return my e-mails maybe I'll have it this weekend to start getting some paint down.

Also did some polishing and even a very tiny bit of fabricating. 

I made a new dash board following Herm's tip from the $50 mod thread:

It's replacing this one so I'm thrilled with how much better it looks:

I started putting together the tubes that Herm did, but my triple tree has a mount that I can use for this so I won't need the risers.  I'll keep them around in case I decide to elevate a bit.  The only problem so far is that my amber LEDs are different shades.   ???  They're only $2 at Radioshack so I'll grab another and use the odd one for my high-beam indicator.  I think I'm going to put it in the top of the headlight bucket.

Also polished my master cylinder, following Sully's vid in the help section.

I'm fairly pleased with how it turned out since I haven't done much polishing before.  It's definitely a lot better than it was before, but this was probably my least favorite part of the project so far.  Sanded a little every night last week to get out the nicks, gouges, grime, and wierd paint from PO.  Still some scratches visible, but I'm happy.  I still need to polish the bottom half of the bar clamp and figure out what to do with the cap.  I'm thinking I may paint it.

The last thing I got done this weekend was my lower fork tubes.  They were pretty grimey with some serious corrosion.  I was planning to polish them up as well, but after getting them sanded down, I kind of like how they look.  My daily rider CM400 has that brushed look on the forks and I may keep it with these.  In fact, I liked the look after hitting it with 180 grit paper so I may go back to that.  Not sure yet, polishing them would be simple at this point since they've had the super-fine sanding.  I'll think on it:

Should be getting my new drag bar and controls in the mail this week so hopefully I'll have some reassembly shots later in the week.

Offline redryder

  • Posts: 1
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #6 on: Aug 14, 2009, 20:00:24 »
Just stumbled upon the site and your build.. I have recently obtained a pair of non running CM400s as and will be following with great interest.  I can relate to your balancing act re. wife/job/money/motorcycle (I can substitute my 4yr in place of your dissertation ;D).  Looks like you're off to a good start! 

Offline dcwp

  • Posts: 559
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #7 on: Aug 15, 2009, 10:27:27 »
Hey Redyrider!  Welcome to DTT.  Be sure to check out some of the other CM400 builds around here if you haven't seen them yet:



Maritime_Biker and a few others have cm400s too, but I'm too lazy to find them right now.

These were my first bikes and I'm finding them surprisingly easy to work on.  Let me know if you need any help getting yours running.

I've started reassembly on my bike, the front end is starting to take shape.  Of course I also misplaced my camera so no pics yet  :-\  Hopefully I'll find it this afternoon.

Offline Deviant1

  • Posts: 1874
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #8 on: Aug 15, 2009, 15:06:49 »
I'm liking this build. What do you plan on doing with the seat? I think these bikes look great with the factory seat trimmed down and maybe shortened. Making one out of fiberglass would be fun too though.
I've been doing a LOT of sanding, painting, refurbishing lately. It's definately worth it when that stack of "finished" parts starts to get bigger.
Also I kind of like the gold. Like you said it goes with the green very well. It'll definately look clean, and you could put one of those chains with the gold sides on to match it further.
Looking great man, keep it up!
'That's the VJMC. They don't like us... because we cut shit up." -Tim @ Barber 2010

Offline dcwp

  • Posts: 559
Re: That Little Dolphin's Got Fire In Its Belly! (CM400)
« Reply #9 on: Aug 15, 2009, 18:56:08 »
Thanks man!  That's a great idea about the gold chain.  When I get to that point I'll definitely have to consider it.

The seat is still up in the air (actually it's leaning against a fence, but you know what I mean).  I'll probably keep a two up seat since the trophy wife loves to ride around on the back of the bike, but I haven't talked her into getting her own endorsement yet.  I really like the brat style seats.  This bike is a big inspiration for my project and I love the seat:

I'm not set up to weld though so getting the hoop is going to be something to figure out.  I have a friend who makes high-end shoes for customers who want something uniquely fit to their feet.  I'm thinking of having her help me when I get to that point so I get a sweet upholstery job.  I may start with a stock CM400 seat pan for ease if I can find a good deal on one. 

Anyway, I finally found my camera.  So I'll have some more pics up later.  But first I'm off to the new Cafe shop opening to snap some photos there.