First time cb400 Project

sxecafe

You think the Carpet Pissers did this?
I’m new to bikes. I got a license in Dec of '07 and purchased my first banger two weeks ago. I bought this MF'er for $875.00. It was running and braking well except it had fuel spilling from the carb over flow tube. My guess it was ‘cause the floats and needles were rusted up from the 1/8" of rust I found in the tank. I have already torn it apart in the hopes of giving it some sweet style. Now I’m waiting for parts to come in. If I can stay under 2K with out tearing the engine apart I will be pretty happy for my first bike. If this is something I like as much as I think I will, then once this one is finished and I have a few thousand miles under my ass then I want to rebuild an older 550 from the ground up. Here is what I have done so far:

Here it is when I got it home:


Some sweet electrical tape grips... You can pick them up at your local bike shop


I took the front can off to put on new indicators. There are low rise bars, new grips, bar end mirror on there.


No Tank or ugly seat after the first mods...


Stripping the tank:






After some 400grit:


I have cleaned out the tank with Rudy's Zep's Lime, Calcium and Rust remover trick and it worked wonders. Now I'm waiting for new mini gauges, a new tail light, and carb rebuild kits. I want to reshape the seat to make is smaller, modify the brakes (either dual disk or just change to a dual piston caliper with new lines and pads) and paint it. After that it should be a sweet whip to move around town and get to work in. Let me know what you think and Ill keep you posted on the progress.
 

Kev Nemo

Honda Hacker
a sweeter ride than the Ferrari behind it in the garage? ;D

What's the name of the paint stripper you used on the tank?
 

sxecafe

You think the Carpet Pissers did this?
Ya... My pops has a 360. I couldnt really get that out of the pic.

I dont remember what the stripper was called but it was from Wal-Mart (I know I know, but it was the only place that had it).
 

Canuck Plumber

Badges? We don't need no stinking badges!
Hey, awesome, another 400. Is that the CB or CM? I can never tell. I have the same frame. This'll be great to watch another 400. Nice to meet you btw. I have lots of extra parts and manuals so if you need anything let me know.

Cheers
 

kneedragger

New Member
Just an FYI, since you're interested in upgrading the brakes...

IIRC, back in 1981, Honda put MUCH better brakes on the '81 CB400T (the Hawk); unless I'm mistaken, they added a wider reverse Comstar front wheel (probably 2.15 x 18"; the earlier wheel was 1.85 x 18"), and installed a better (thicker yet lighter) brake rotor, a better caliper and master cylinder, and better pads. According to the magazine articles of the day, Honda simply raided the parts bin and used the CB750F components in a single-disk setup. They also used a better (cast) triple tree, and dumped the older (and more flexible) stamped one they'd used on the earlier models... SO, just some food for thought; you might want to look for an '81 or '82 Hawk front end, including the wider wheel and all the brake components. The only drawback I can think of is that you'd then have a reverse Comstar wheel up front, and that plain Comstar in the back, though a LOT of people have drilled out the rivets and modified their Comstar wheels; I'm pretty sure that at least one of our DTT brethren has also made that mod... I for one MUCH prefer the reverse Comstar look, and I can say from firsthand experience that the standard Comstar design is a NIGHTMARE to keep clean...

Hope that information helps you...

-- kd
 

zixxerboy

New Member
I would think long and hard before I considered spending up to 2000$ on an old 400.

Don't get me wrong - I love vintage stuff ( none of the runners in my garage are less than 20 yeras old - the daily driver is a 79)

But for me the lure of vintage is that they're cheap too. About 2$/cc is the tops I'd pay for an old runner. My 79 KZ650 was a 1$/cc special - only needed a front tire and wiring clean up to pass the safety. I've put 10,000 trouble free kms on it since last July.

At least that's my 2 pennies
 

Canuck Plumber

Badges? We don't need no stinking badges!
Well, guess I'm over the limit. If your looking to make a return on your investment of the bike you purchased then I would have to agree on Zixxerboy's comment on the max amount to spend on this bike. Personally I've spent close to $5000 and I'm nowhere near finished on my CB400TII (Now a 450 with an engine swap). If you're doing this for the right reasons then it doesn't entirely matter how much you spend (granted, people will call you crazy... but then I like crazy). Like any hobby, bikes can suck the life out of you and your bank account if you let it... I work my arse off so I don't mind blowing money on something that will never come close to the amount I spend on it. Anyway, if you want to dump a shwack load of moola on yer bike... all the power to ya... it'll make for some great beer drinking stories later....

Cheers
 

sxecafe

You think the Carpet Pissers did this?
Canuck Plumber said:
Hey, awesome, another 400. Is that the CB or CM? I can never tell. I have the same frame. This'll be great to watch another 400. Nice to meet you btw. I have lots of extra parts and manuals so if you need anything let me know.

Cheers
Hey Dude,

Nice to meet you too! I like what you have done to your bike so far. Mines a CB 4. Question for you I see that you have some different exhaust tips... which ones did you get and where did you get them? Also, What about painting the wheels? Just normal rustoleum or was it like high temp?

Thanks for the response.

RT
 

Canuck Plumber

Badges? We don't need no stinking badges!
The pipes were from a local supply shop called Cycle City. They're called stubby or shortys exhaust. They are slightly illegal due to the extremely loud noise they allow the engine to make. Out here in Calgary the police arent too concerned about regulations. You'd be surprised what you can get away with. As for the rims I had them powder coated. You cant really paint them because the paint chips off when you mount the rubber. Check a few local powder coat shops. I had mine done for about 50 bucks. (Theyre black so the color is common and cheaper than something like say green). My bike was a 400T but the engine was pooched so I bought a 450cc from an 84 CB. The mounts were the same. I kinda wish I had kept it. The old engine had a kick start and the new one is only electric. These bikes are wickedly easy to tear apart and rebuild. What did you use to get the paint off of the tank? Ive seen a few guys here use it but never asked. Btw check your mail.

This is basically how my bike started out. (Not as nice as this pic)

 

sxecafe

You think the Carpet Pissers did this?
Finally! I had some time to upload and write some updates to this project. Things have been moving along lately. I have been riding and having a blast. Here are some pix of the progress:

Here is how it looked after I stripped the tank:


I cleaned the dirty ass carbs but I think they are part of a new problem:


I painted the crank case with some high temp:
Masked

Painted

With an unpainted tank shot (maybe I should have kept it unpainted...)


The tank with etching and builder primer on it:


I dont have new pictures of the finished tank but I will update but I will post some soon.

My Gauges came in!!!!:

A Side view of what was once a four foot console:


Ill have more photos very soon.

Next I have to upgrade breaks, finish painting the rest of the bike (i.e. fenders and covers), polish the metal, and fix this big 'ol seat. However, as I was riding this weekend I started to experience some serious throttle bog down as I was coming up my hill. It literally died right as I got to my driveway after a morning of riding. Now I have a very hard idle and a throttle that bogs for a few seconds and then clears up at high rpm although thats only when Im standing next to the bike, not riding it. I can barely get the thing to move! If it idles for more than say 10 seconds it ends up dying. Im worried I threw a rod or something but think that maybe my tank is still really dirty and rust is back in the carbs... I dont know. Im going to post a video of what Im dealing with in a subsequent post so not to load this one up too much.
 

dcmspikes

New Member
yeah, check the tank. i went throught he petcock and later had similar problems. after going through everything else three times, i checked the fuel flow and it was the petcock.
 

sxecafe

You think the Carpet Pissers did this?
Here is an example of what Im talking about.
[youtube=425,350]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/bgtamR2B0EI&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/bgtamR2B0EI&hl=en&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>[/youtube]
 

HerrDeacon

Active Member
Sounds like its running out of gas. After it cuts out, can you start it back up again? Do you have enough gas in the tank (i.e. is it in the reserve zone)? Not sure if you have a vacuum petcock, if so check the vacuum hose.
 

sxecafe

You think the Carpet Pissers did this?
Yea I can start it again after it cuts and yes there is enough gas in the tank I had just filled up when this started to happen. Im not sure if I have a vaccum petcock either, how would I know?
 

sxecafe

You think the Carpet Pissers did this?
So it looks like I have a stuck piston, which is real shitty. I was trouble shooting a few things and I definitely am running on only one piston which would explain why it sounded like a lawn mower to me. Heat on only one exhaust pipe, the engine dying after it idles for a second. Yup only have one piston running. GREEEEEAT.

I have spark on both side (I know cause I shocked the shit out of myself even when I was holding the part of the plug I was told would not send serious voltage through my whole upper torso). I really dont think that any gas was getting to the right side. I took the carbs apart again to find they were filthy after two weeks of riding with what I thought was a clean tank (looks like its time to put the newer cleaner tank on) and I think that has something to do with it. Also, the fact that I burned through the oil much faster than I thought I would have and found the oil to be pretty low. I guess I may have the chance to pull the engine out after all although, Im not really too happy with the circumstances. What to do, what to do?
 

Canuck Plumber

Badges? We don't need no stinking badges!
You don't have a vacuum on your petcock. As for the lack of ignition in one of your cylinders its most likely one of the carbs. You can try two things; one would be to run some fuel treatment through your gas to free them up (might not work if its completely gummed up) the other is the rebuild the carbs. I'd go with option number two. Its not that hard and there is plenty o' reference material available for those carbs.

Check out this site for the micro fiche on the bike.

http://www.mrcycles.com/fiche_select.asp
 

brewtown16

what, me worry?
ive been lurking in this post for a while.... figure id throw my hat in the ring.

well, you said you cleaned the carbs out. now, did you take out the needles or play with the jets? it might just be that your float is off, and you need to re-set it. i hat that prob with my previous bike when i was learning. it would do the same thing, start up, run fine, then die. might also explain why its only running on one cylinder.
 

Canuck Plumber

Badges? We don't need no stinking badges!
Have you checked the compression? Just curious to know if one of your cylinders is in need of new rings.
 

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