Topic: IDK Numero Dos - 1975 Honda CB400F

[minimo]

Thanks for your insight and expertise, fellas.

calj, I am definitely keeping these Mitutoyo‘s in a safe place

I will try to get proper torque measurements of the rods soon (sans bearings).
I did make an attempt at it but with rod nuts tightened not to spec (but tight) - it was difficult to get a handle on 14 ft-lbs while torquing (especially difficult without a shop vise and a good socket to fit around the nut without slipping - what kinda shop is my living room?). But, to give you some idea, here are those results:

1, 1.3796” = 35.0418mm
2, 1.3769” = 35.9732mm
3, 1.3790” = 35.0266mm
4, 1.4210” = 36.0934mm

Thanks again!


Sent from my iPhone using Tapatalk

[MoMo]

I included a spare crank and rods with a recent sale to a forum member..  He may be interested in selling...Larry

[minimo]

An impulse buy on eBay. I hope I made a good choice.
This was advertised thusly and I fell for it. $130.00 USD (included shipping):

For sale is the crankshaft and connecting rods from a 1972 Honda CB350F. This will fit the following models:
CB350  72 thru 74 (F and F1)
CB400  75 thru 77 F
This crankshaft is in very good condition. There is no abnormal wear. The journals are very good with no grooving nor pitting. The connecting rods spin freely around the crank. The oil seal on each end is good and can be reused. I used the correct tool needed for removal of the rotor from this crankshaft and there is no damage to the threads that for receiving the UBS bolt. The crankshaft bearings are included and look good to be able to reuse. This crankshaft and connecting rods is about as good as you will find in a used crankshaft.

Well, it all looks real good. Certainly better than what I currently have; we shall see.

Doh. And a note that I overlooked: "This seller is currently away until Oct 15, 2018. If you make a purchase, there may be a delay in processing your order."

This means that I'll have to wait at least a week...

[minimo]

Dah! I probably shoulda waited, eh, MoMo?
Oh well. Thanks for the shout.

[minimo]

A bit of a concern here with info I pulled from Wikipedia:

Honda CB350
Bore / stroke: 64 mm × 50.6 mm (2.52 in × 1.99 in)

Honda CB400F
Bore / stroke: 51 mm (2.0 in) x 50 mm (2.0 in)

Will a 350 crankshaft work in a 400? Likely to work better vice versa but... crap.


Sent from my iPhone using Tapatalk

[minimo]

An update. The critical distinction is that the crankshaft that I won on eBay is from a 350F. The “F” is always critical.

Honda 350F
Bore / stroke
47 mm × 50 mm (1.9 in × 2.0 in)

Should fit, but how well?


Sent from my iPhone using Tapatalk

[Little_Phil]

The CB350 (no F) is referring to the twin.
CMSNL list the 350 and 400 four cranks as the same p/n 13300333010 so should be safe.

[minimo]

The CB350 (no F) is referring to the twin.
CMSNL list the 350 and 400 four cranks as the same p/n 13300333010 so should be safe.

Thanks for the confirmation, Lil’Phil


Sent from my iPhone using Tapatalk

[minimo]

Trying to be a good son - my dad is recovering from eye surgery and I’m filling in on yard work duty. Noticed the robustness and ingenuity of this chain tensioner on his Briggs & Stratton 3HP Original Trimmer...

Eesh.


Sent from my iPhone using Tapatalk

[strynboen]

a wooden block vas better..to hold it organic and green

[minimo]

a wooden block vas better..to hold it organic and green

I agree - to keep it ecological. This metal hitting metal business, in runs in my family bloodline.


Sent from my iPhone using Tapatalk

[minimo]

Soon to be bling or paperweights?



Sent from my iPhone using Tapatalk

[minimo]

I got my replacement camshaft/rods. It looks in good condition

Off the bat, here are some readings...

Main Bearing Journals (nothing out of round)

1 - 31.9887
2 - 31.9862
3 - 31.9887
4 - 31.9887
5 - 31.9913

I still have the rods to measure but I want to wait until I have the proper thin-walled socket to remove and torque the nuts and a good vice to keep them held in.

Meanwhile, given the readings above and my case being marked BBBAA, can I determine what bearings I should get from those measurements? Or, do I use my existing bearings to Plastigauge and determine the runout from there as a starting point? The purchase of this replacement crankshaft came with a set of ( bearings, all in great unmarred condition that are stamped consistently, “D2F-A STD”.



Sent from my iPhone using Tapatalk

[RAFster122s]

Kevin and  Minimo, perfect for that junk crank to use for a man cave lamp.. Mount the base on a old worn out brake rotor  and bolt the crank to it. Fabricate a wire holder for your  lamp shade. A very cool LED light at a local library was these giant rings of aluminum with white pair or white Anodize. And the LED strip lighting was attached to that. Very very cool! So mount an old spoked rim to your crank  and line the painted tube side with the LEDs or a  more friendly design would be to mount the LED tape to the top and bottom and extend the adjustable voltage LED controller  dial with a knob that looks like a knurled speedo knob. Get creative with brass tubing from hobby shop and your soldering gun/iron/torch to
Have two controllers and two switches one for top and one for bottom. Wanna get tricky for the power switches. Repurposed an old jeweled horizontal  dash light set for neutral, high, oil pressure, low beam to have two of the jewels be connected to your oil pressure and neutral lights and use a led to backlight the hi or low beam when you turn on the top or bottom or both LED strips. If you need more space beneath the brake disk use some old gears that are the same height and rivet or cap head socket screw them to expanding sleeves like you find on bar end mirrors to attach the gears securely to the stainless rotor...unless you can weld stainless and the steel in an old gear set. Then you can weld or braze things together... Some heavy high density felt from McMaster Carr for gluing to the bottom of the rotor or gears... Or better yet use your old con rod and a couple others to form outriggers on the rotor to make it more stable.

Mix up some polyurethane with brown coloring to simulate a wet oil coating and spray all the degreased parts after you have them cleaned up. Tape off the journal areas and give them a shot of clear or coating of clear polyurethane. Use oil based urethane instead of water based in case you have a bit of oil not cleaned from a part it might be less apt to destroy the poly coating there. Give it several coats and you could use satin or gloss poly.

Copyright & Trademark Oct 2018 David - RAF122S for Lamp design ideas
All royalties and proceeds from licensed use of this copyright or trademark will go to motorcycling obsession and care and feeding of CB

[RAFster122s]

Trying to be a good son - my dad is recovering from eye surgery and I’m filling in on yard work duty. Noticed the robustness and ingenuity of this chain tensioner on his Briggs & Stratton 3HP Original Trimmer...

Eesh.


Sent from my iPhone using Tapatalk

Fabrication opportunity to have an adjustable sprocket wheel serve as tensioner in the same chain pitch/size of course. Would be something if it were the same as the 530 on a cb bike.

[minimo]

Wow, RAF. What reefer are you smokin’ this evening? Cool light idea


Sent from my iPhone using Tapatalk

[RAFster122s]

Never in my life have I smoked reefer or cigarettes... Really, no joke. Nor eaten reefer...

I have snorkeled a reef in the Caribbean, was fantastic!

David

[RAFster122s]

1-day delivery
https://www.amazon.com/Anytime-Tools-Micrometer-Precision-Machinist/dp/B0045UZGSC/ref=sr_1_6?ie=UTF8&qid=1539084542&sr=8-6&keywords=micrometers

That looks like a great deal...

[minimo]

So first, the boring but important stuff.
Here are the Plastigauge results of my replacement crankshaft and rods.

Crankshaft Mains
1 - 0.051
2 - 0.051
3 - 0.038~0.051
4 - 0.038~0.051
5 - 0.051

Connecting Rods
1 - 0.038
2 - 0.038~0.051
3 - 0.038
4 - 0.038

Crank main journals
1 - 31.9887
2 - 31.9862
3 - 31.9887
4 - 31.9887
5 - 31.9913

I failed to get proper con rod journal measurements but base on some cursory measurements to check in roundness, the average was 35.0189mm. For this though, I will rely on Plastigauge...

I admit that I’m still not 100% on the bearing/clearance chart but I’m certain that these Plastigauge results are accurate. I’m semi-confident that based on how I’m interpreting Kevin’s explanation of the charts that at least my mains are within spec (“crank mains and big ends should not be more than 32.0mm can go down to 31.97mm... if you’re under 31.97mm crank will need to be replaced”).

That’s all, folks.

Time to button her all up?


Sent from my iPhone using Tapatalk

[minimo]

She rides again. Smooth as buttah. No more knocking.

She advances forward a bit at stops though so likely a clutch adjustment. A little carb sync and maybe I can get a little more rides in before tightening her up a little more to work out some more kinks.


Sent from my iPhone using Tapatalk

[Don R]

 There were some 400F's sold that were under 400CC's for sale in countries where they were restricted or taxed. They used a slightly shorter stroke crankshaft. Most 400's are 408CC, I think the odd ones are 394cc or something like that. That may account for some odd stroke numbers floating around in the spec books. If I recall correctly Japan and France got the smaller ones.

[minimo]

Got about 20 miles in on this rebuild that includes the replacement good-condition crankshaft, rods, bearings, brand new primary chain, new pistons and rings, newish clutch discs, valves lapped and seats replaced, Shell Rotella 15W-40 Diesel engine oil, did a carb sync... still getting quite a bit of smoke coming out of the breather. I imagine I need to get more rides to wear in all these fresh parts?



Sent from my iPhone using Tapatalk

[minimo]

My bike is talking to me and it’s telling me it’s not well. 1st gear is doing a funky thing where it’s not engaging properly and I’ve even had to take off from 2nd gear for fear of damaging 1st gear...
Now, the clutch is adjusted to where I can actually shift out of and back into 1st but something in my set up still doesn’t look and feel right.

Per the manual:

After turning in to loosen the clutch cable adjustment at the handle I loosen the clutch adjusting nut and turn the clutch adjusting screw clockwise but I’m not feeling much resistance per the manual. So I’ve screwed it in all the way to where the nut can be flush with the end of the slotted screw and then turn it back counterclockwise about a half turn.

Here’s what my adjustment looks now. This can’t be right, can it?:

Clutch cable adjuster looks way too high.
Maybe my clutch cable is too long for clip-ons?




Sent from my iPhone using Tapatalk

[minimo]

So I have my clutch adjustments set now to where I can get into and out of 1st gear okay, but there are intermittent jerks and sometimes rattles to where it feels like the gears are slipping and then they engage. I still don’t have enough miles put on yet since the recent engine rebuild so I’m going to just chalk this up and keep a close feel and continue to make these small adjustments as I work it all in. The current break-in oil I’m using may also have everything to do with these issues:

Rotella T4 Triple Protection 15W-40 Diesel Motor Oil -1 Gal.
https://www.homedepot.com/p/300387920

But I’ll keep this stuff in there for a while as I work out the kinks. Excited to see what shiny bits of metal lay in the pan come oil change time.

Meanwhile, I must say that I LOVE my Bridgestone BATTLAX tires. So fun on the handling and far superior grip than Dunlop. This also probably means that it’s a softer rubber = more frequent wear and tire changes. Worth the ride, I say.
I’m also pretty new to clip-ons and rear sets and riding in this dumb squashed posture, but I think my old bones are finally adjusting. I’m limited to my clip-on adjustment due to tank clearance but after a while the wrist soreness has gone away I was also feeling a bit sore in the knees, almost like I had hit the ski slopes but after a while, this mild pain too has subsided. I’m going to keep riding and working the bike in - get it hot and let it rest, and repeat. I’ll eventually get to upholster the seat and paint the tank. I may add more height to the foam on my seat for improved positioning and comfort. Just the finishing touches now, I hope. Couldn’t have done it without all the help here. Thanks, y’all!
It’s Sunday and I’m going to get a ride in. See you on the road



Sent from my iPhone using Tapatalk

[minimo]

Here's a link to a STEP file for a REAR WHEEL BEARING COLLAR B, 42625-286-000 that was modeled in Fusion 360. It should be adaptable to most Honda CB/CL/SL motorcycles and is quite a crucial part if you want your rear wheel to roll without a dumb wobble or to not explode any bearings and possibly damage other parts and things and people and/or yourself... I'm not saying that this was a recent uncovering of mine but in case anyone should stumble onto this thread and would find this to be a relevant topic


The linked model was created in Fusion 360.
In case you wanted to have one CNC machined or printed out of some sintered metal:
https://a360.co/2QGGtnk

Since I had some aluminum scrap, I decided I'd make a collar today just for fun.