cm400a

I recently picked up this 1981 CM400A from marketplace. It runs, but needs some work. I've built and restored all sorts of things, but this is my first vintage motorcycle, so it's a bit of a learning experience. (Pictures are of it pre-restoration.) I've already done some things, still lots to...

I made a small video showing how a properly tuned Hondamatic should respond. When you do this check you really ought to use a portable tach. However, it can be done ear. If you can't achieve a good idle there are a number of things it could be such as: Dirty idle jets Shrunken or missing...

i have a 1979 honda cm400a that i’ve been rebuilding for about a year now. my main issue is that it’s all crank, no turn over. brand new battery, ignition coil, valve seals + engine gaskets + timing adjusted … but i believe my problem lies in the vm28 mikunis i installed. i have to set the idle...

We have an on-going thread here with a forum member trying to locate those critical torque converter cover gaskets. Right now there is one with the insane price of $150. With that said, I did some research and found who manufacturers the gasket kit for 4-into-1. I've reached out to them about...

I have to replace the 16005 bearing in my CM400A outer torque converter case. I could find a large pipe that fits the outer diameter, a bearing driver set, or a socket of the right size that also fits the outer diamater. However, I don't have this size laying around and an old trick if you...

⚠⚠NOTE TO THOSE WHO USE THIS AS A GUIDE. WHEN I REFER TO BOLT SIZES I AM REFERRING TO THE SIZE OF THE HEAD⚠⚠ I'm not 100% ready for this yet, but figured I will start some documenting here. I have 34,700 miles on my 79 CM400A. I originally had about 12,000 on it when I first got it back in...

I've been using GN4 for years, but figured at $15 for a gallon on Amazon for Shell Rotella T4 15W40 why not give it a try? I know others here have used it with much success on the 400Ts. I'm pleased to report works just fine; as expected. No issues with torque converter slipping or trouble...

Hello to all VHT Members, I've setup a community test kit for diagnosing ignition/no-spark/bad performance conditions. Swapping your parts with the ones out of the kit can help you diagnose if you need a stator, CDI, or coil. The kit includes: Prototype CDI Known-good Ignition Coil with new...

Hi guys, I am going to use this thread to document my tune up of my CM400A. I am hoping to do the following 1. Replace the chain 2. Replace both tires (they are from 1999) 3. Polish the chrome 4. Clean the brakes 5. Lube everything that needs to be lubed 6. Replace the front brake handle...

Hi everyone! Hope all is well. I recently purchased a 1979 Honda CM400A and it rode perfect on Thursday but wouldn't start on Saturday with nothing happening to the bike in between (it was under a tarp, dry, sunny conditions). A very nice user on Reddit (and here I'm guessing) by the name of...

Found this while perusing craigslist. Not sure if he'll ship or not but looks like there's some good original parts. Little crusty looking but apparently engine fired and carbs are moving. https://hartford.craigslist.org/mpo/d/storrs-mansfield-parting-out-1981-honda/7563205113.html

FOUND I'm looking for a change switch for my 1979 CM400A. The same switch was used on the CB and CM across the 400 and 450. From what I can tell this is a notoriously hard part to find but should be on any of those engines, if you're doing a tear down please consider pulling it off, it is the...

Hello, I've been working on reverse engineering the Hondamatic CDI for the CB400A, CM400A, CM450A bikes. It's now been successfully road tested for more than 3000+ miles in stop and go traffic, and highway. Over 20 sold. Here is a video of the prototype running on my 79 CM400A: CURRENT...

My kickstart shaft broke, so I bought a new one, but I'm having trouble getting everything to fit properly, so the kickstart just feels very spongey when I try to kick it. I can't find the punchmark on the new shaft, which is part of the issue, but then even if i do get everything to fit, I...

Tomorrow is my 79 th year on this old earth. I am starting to fell every one of them so I closed the shop . I will finish the CA 95 but its my last one. Its been a good run but its time to slow down. For those who Have A models I thought I would leave a few notes. All the A models , the 400...

Hello all! Having issues with BOTH of my Hondamatics! I'll try to keep my rambling down. 1979 CM400a- A history -I've had this bike about three years. -Bought it not running. Towed it to the shop I use. (Specializes in vintage bikes...) -Tires, carbs, oil, little things and up and running...

Hello all! Having issues with BOTH of my Hondamatics! I'll try to keep my rambling down. 1978 CB750a- -I've had this bike since February. -Bought it running, but not well. Towed it to a friends for cosmetic work. -Added hard bags from the 400a. Fresh coat of paint for the whole thing. Shined...