First bike, first post - '78 Honda CB400

[jbrowne609]

Hey guys, my name is Jason and I have really fell in love with the cafe style (and this site) over the last few months. I am finishing up school in Philadelphia and really wanted a bike to work on over this winter that I can have ready to ride for this summer.

A little background. I have limited motorcycle experience, although I have ridden minibikes and mopeds before (please limit your laughter!). I recently started shadowing and working at a garage near where I live and have learned a lot about mechanics that I didn't know before. While this doesn't all the sudden make me an expert, or even qualified for that matter, I thought I'd take the plunge and start learning about bikes by, well by working on one. I looked all over the web for a decent deal but either nothing was in my price range (<$1000) or it wasn't titled (something I have heard nightmare stories about for PA). A few weeks ago I spotted a craigslist ad for a '78 Honda CB400 in good condition, but not wired or hosed for $1,000. I pulled the trigger and am now the proud owner of that bike, title and all. Now for the fun part I assume.

The previous owner said the bike runs but needs a few things such as wiring for lights, horn installed, rear brake arm, and the gas tank cleaned. The guy he bought it from had recently cleaned and had kits put in the carbs and said I shouldn't have a problem other than the needles sticking a bit at first.

I am beyond excited to work on and learn from this bike (as well as all of you, which I have been doing for a bit now) but I wanted to show you all the bike and get some input from you all as far as what I should do first. I will note that I want this bike to be reliable and long ranging as I want to take some long haul trips. I will take any and all suggestions and I look forward to keeping you guys posted on this! Pictures to come

Cheers,
J

 

[jbrowne609]

The bike as I got it

 

[jbrowne609]

More pics

 

[jbrowne609]

and more

 

[jbrowne609]

last batch. Air box seemed pretty clean, and for that many miles I guess I should expect it to be that way

 

[VonYinzer]

Welcome to DTT. Those 400s arent the fastest but if you take care of them, they'll go forever.

 

[yorkie350]

Hi fella great clean looking bike to start a cafe project ime new to the site and on my first cafe racer i aint no mechanic but got some good ideas n tips if ya get stuck first tip dont count the bucks ya put into it well not till its done at least haha engine wise check n change as much as ya can i listened to the guy who sold me mine now its nearly comp it aint runnin right might have to pull engine apart cos i didnt change piston rings cos i was told there ok ! damn !!good luck mate (if in doubt polish it ! )

 

[jbrowne609]

First of all I just want to say that after browsing a few dozen build threads, I am inspired by how willing some members are to help other riders. It'd be one thing if it were simple Q and A but this is a full blow mechanics school!

So I am honored to ask your help as I may have hit my first snag. I made a decent amount of progress today taking off the carbs, exhausts and peeking into the cylinder head. Head looks pretty good to me (but then again I'm not a mechanic) but not sure about the crankcase though, maybe just needs cleaning.

However, I wanted to take a look inside the carburetor and see how far I could get dissassembling while following the Clymer guide I just got (!). I didn't get too far...

The primary main jet and the secondary main jet cam out no problem but the needle jet holder is not moving. I have tried pushing and unscrewing but I have a feeling it may be either stripped, stuck or both. Are there any tricks for this kind of thing or should I start looking for a new needle jet holder?

Thanks!

 

[jbrowne609]

And just another pic of my needle jet problem

 

[roman_dog]

I'm not sure about your needle jets, but mine just press in. The needle jet is notched and must be aligned with a small keyway, but I just tapped it out with a hammer and drift. Do it very carefully though to see it it moves or not! Good luck.

 

[yayuppp]

It screws out. I had the same problem. I ended up stripping it, and had to carefully drill it out. The re-tap the threads to get them nice and straight. I'm still having idling issues but I think that is because of the pipes and jets.

 

[jbrowne609]

Long time no post but finally getting the bike back together. One problem I am having is getting the throttle to work properly. We got it hooked up correctly, however there is no spring back from full throttle, it just gets stuck. My guess is that the cables are just too old and rusty. Anyone had this problem before?

Also, the cylinder head cover is giving some play, is that normal for a bike this age? Maybe I just need new gaskets?

 

[Dannomite]

One problem I am having is getting the throttle to work properly. We got it hooked up correctly, however there is no spring back from full throttle, it just gets stuck. My guess is that the cables are just too old and rusty. Anyone had this problem before?

It could be that they're not adjusted properly, old and sticky cables or the routing is causing too much friction within the cable. First look at the routing. Bends and kinks are something to avoid and the cables should have nice big bends in them. To make mine work with my CM400 and clubmans, I had to reroute them over my headlight as apposed to under (how they used to be). If that doesn't solve the problem, look at the adjustment of the cables. You still want the throttle to snap back with the bars turned both left and right. Finally, new cables could be what you need. I got new push/pulls on eBay for $24 on my ride.

Also, the cylinder head cover is giving some play, is that normal for a bike this age? Maybe I just need new gaskets?

It shouldn't have play. Once I popped my valve cover off to adjust my timing, my valve cover gasket was done. I put it back on to only find out it now leaks. Another eBay purchase for $12. Just make sure the engine is cold when taking the cover off or you can risk warping the cover (which hopefully isn't your problem). Just don't over tighten because those head bolts can snap off. Make sure the bolts are clean and lubricated so in the event of then snapping, they will spin out easily.