1975 CB400F Project "Replacement Girlfriend"

well it rides well enough with the neighbor kids pushing me around the cul-d-sac ;D

Hey thats not a bad idea....
I cant seem to find any cheap sportbike forks around here, they all want 400 bucks for the front end, "its been on craigslist and hasn't sold for 3 months, ill give you 100" and they all say nah I think Ill keep them.

puddle pirate said:

Keep in mind a EX250 front end bolts right on.


I also think i still have the whole front end somewhere in the garage.
JT

Click to expand...

SO did you just get the whole front and and bolt it up triples and all?

I found a guy that had it on CL for i think 80 bucks. He had taken a cheep 250 ninja, made the motor into a rail and had the empty frame sitting around. There are a few of these builds if you google search 250 ninja and CB400 they pop up. I think there are several on this site. Honestly i decided to go this route because I wanted a cheep build and the original old front end, front and rear rim/hub were in horrible condition and i thought it would be fun.
Here is one of the builds http://www.dotheton.com/forum/index.php?topic=29721.0
Yep, whole tripple bolted right on, I put new bearings in and milled down one of the old bearings to use as a shim, 3/16 gap if i recall. Rear tire, I used all the ninja spacers but the original axel and chain tensioner assembly.

1975 CB400F Project "I'll think of a name later I'm too excited at the moment"

Installed some 38 pilot jets today and that made a huge difference. I finally have some power in the lower Rpms and taking off from a stop is easy finally.

I can feel my bench sync on the carbs is a bit off, need to find someone with a manometer or make one to get them dialed in just right but it's running like a champ. Went for a 120 mile ride tonight and it performed flawlessly aside from a bit of smoke from the breather but I checked the oil and its a little high so I think that's the cause of that.

I'm getting used to cruising at what seems to me ridiculous Rpms. 70 is about 6k which with this kerker exhaust (straight through with no baffles) is very loud haha but I've gotten used to it and love it.

Loving it more every day.

Glad to see that stuff worked out for you. Have to go on a cruise someday

1975 CB400F Project "I'll think of a name later I'm too excited at the moment"

Been getting more and more comfortable with the bike loving it more and more.
Tonight I finally got an open stretch of highway and opened her up.
I hit a little over 100 and then let up.
That was at 10,500 in 4th....
So I'm curious what my actual top speed is if I shifter to fifth. It was still pulling hard at the top of fourth ad a shift to fifth should put It back in the power band.
In guessing its got 115 in her.

But this seems wrong. But I've checked my speedo with GPS and its spot on.
Anyone know what the theoretical top speed of a 400f is at the top of 5th?
Or 6th even?

Holy crap! Sounds like she's a goer.

1975 CB400F Project "I'll think of a name later I'm too excited at the moment"

I'm thinking I may not have stock gearing. Because according to the calculator I just used I should too
Out at 91 in 4th.
Hmmmm

Maybe I've got speedo error way up high but not down low?
Sure felt like 100

sounds like the replacement girlfriend is fast and loose.
Stay safe

BRAAAAAPPP