Author Topic: CB400F Questions and Dilema's (Read 11398 times)

LoopsAndLogic · « **on:** February 12, 2007, 04:54:46 PM »

Hello,
I have a 75' CB400F with 22k and it has the cam chain stretch which is causing loud upper and lower rattle.
I suspect it's the cam chain cause the sound is at it's loudest right in the middle of the engine. I used a stethoscope

I have noticed that the rocker cover has been previously removed cause 2 bolts were not placed in there correct location.

My questions are as follows:

1. How long does it take to ship from David Silver Spares?
2. He has the OEM Cam Chain and a Pattern Chain.... Which one would you go with?
3. The OEM chain is endless. Do you think the soft rivet they have would work with the OEM? I would only have to cut one link off.
4. Would it be wise to do a oil pump compression test because of the high mileage?
5. To not risk snapping off bolts and ruining my riding season, should I ride her till she dies and fully rebuild the motor???
6. And lastly, how long would you think I could drive with this mechanical problem?

Thanks guys for your help and any help will be most appreciated

-Mike

750goes · « **Reply #1 on:** February 12, 2007, 05:49:17 PM »

ride it till it dies then you have a real headache...and lots more money to spend

do not know anything about 400's but would think a wise thing is to fix your immediate problem - is the cam chain adjustable?? find out

22k does not sound like a huge mileage -122k probably is..

Oil pump compression (oil pressure ??) test - not sure what you mean here..

LoopsAndLogic · « **Reply #2 on:** February 12, 2007, 06:18:15 PM »

Yes, the cam chain was adjusted by the book and which didn't work. So a friend from the UK told me to slightly press down onto the cam chain tensioner shaft and that sure did work!!!!

But is still rattling. The cam chain is worn.

I mean, test the oil pressure.......Cause that could make things a little louder at the topend.

Anybody here that could answer my questions, that has experience with CB400F's or 350F's??

Thanks!

TwoTired · « **Reply #3 on:** February 12, 2007, 06:23:23 PM »

At 22K it seems rather unlikely you have cam chain stretch. More likely you have a frozen or notchy cam chain tension adjuster which seems to be a common issue with the CB400F. Replacing the chain will, of course, not improve cam chain tensioner issues, if that's what you have.

The 75 400 I once owned had a sticky, frozen actually, tensioner and rather noisy cam chain. I had to tap on the tensioner adjust rod to get the proper tension on the chain which quieted it down A whole lot. I didn't fix the tensioner, I just overcam it's stickyness by feel to get the proper tension on the chain. Fixing the tensioner was way more work than I was willing to do just to get the chain tight.

If you don't already have a shop manual for the bike, get one, study the tensioner mechanism and decide it that is working properly. Night save you the extra work of changing the cam chain.

I don't think 22K is high mileage at all. What makes you think it is? 50 K maybe a top end job. The lower end is likely good for 100K. If you use decent oil and change it a proper intervals.

If you ride it till it dies, you should have a spare motor to replace it with. Internal parts aren't getting easier to find, nor are they cheap.

Oil pressure. Is the rocker adjuster getting oil flow? Why do you suspect oil pressure?

aptech77 · « **Reply #4 on:** February 12, 2007, 06:47:42 PM »

1. When I got things from DS, they took about 1.5 weeks to get it.
2. 22K on the cam chain is a lot. The 400F is known to have had premature cam chain issues at 20-25k
2b. As TT said.......except for the stretch commet "More likely you have a frozen or notchy cam chain tension adjuster which seems to be a common issue with the CB400F. Replacing the chain will, of course, not improve cam chain tensioner issues, if that's what you have." .........
3. I got an HD aftermarket cam chain when I redid my engine.
4. ? Should not be an issue
5. It's a HONDA 400F you can't kill it......
6. As long as you want...

LoopsAndLogic · « **Reply #5 on:** February 12, 2007, 07:13:19 PM »

The tensioner works, it's just the spring on the tensioner has no tension left in it from all these years.

That's why, by pressing on the tensioners shaft slightly and at the same type tightening the locking bolt, you've replaced the
job of the spring.

I've studied the way the tensioner works.

I've also sync'd the carbs!

This method has worked on my 76' CB400F which was sitting in a garage for 15 years with just 11k miles, and it's chain is much quieter now.

The ride it till it dies was a bit to strong, I do admit, but I've seen so many CB's with such a loud rattle and ticking noise with very low mileage.

I will say, this bike was not taken care of properly. If the cam chain was never readjusted, then that would cause the chain to stretch??

And the oil pressure was just a thing to check cause of the mileage. You think it's necessary?

Would worn cam chain sliders cause rattle?

I've never ordered from DSS.

You may want to check this link out, www.cb400f.btinternet.co.uk/cam.htm

Thank you for replying my questions

GroovieGhoulie · « **Reply #6 on:** February 12, 2007, 09:05:51 PM »

The factory camchain stretched bad. I'd recommend a DID camchain. Heavy-duty and would be less prone to stretching, so you wouldn't need to work out your tensioner as much. Just make sure the horseshoe-shaped arm isn't chewed into. It's the one part that is nearly irreplaceable down there and it's the one that wears.

I've heard that you should do the camchain every 10K, but with the HD chain, hopefully it should last longer.

hootle · « **Reply #7 on:** February 13, 2007, 07:47:10 AM »

Guys,

This may help some of you. I had some of the same questions when I first bought my '75, and this, plus a little bit of poking one night with a screwdriver, cleared things up

-Sam

bill440cars · « **Reply #8 on:** February 13, 2007, 07:58:42 AM »

Always interesting to learn of ways to improve our bikes. I'm going to have to take some and read this one through. Aren't the 400F and the 350F basically the same motor? With the exception of the displacement and the trans, of course. What I'm getting at is, wouldn't this info apply to the 350F as well?

Later on, Bill

Jugghead · « **Reply #9 on:** February 13, 2007, 09:11:58 AM »

Hey bill!
I just looked at hootie's post with diagram, and since i just opened up the top end of my spare 350F motor ---see my: "When bad things happen to good motorcycles" post.
I know that they are seemingly identical. the dampers, guide and blade were the same, and when you look at the case, the adjuster is in the same spot and part E is in the same location. I would wager that yes, they are the same.
I just may have to apply that knowledge to my 350F!
Good luck to you all.

dagersh · « **Reply #10 on:** February 13, 2007, 11:26:08 AM »

Hootle,

Thanks for posting that great article. It certainly takes alot of the mystery out of these devices!

Gersh

supersport_CB400F · « **Reply #11 on:** February 13, 2007, 12:29:33 PM »

It looks like this if you’ve never had the engine open guys.

Cheers

Uncle Ernie · « **Reply #12 on:** February 13, 2007, 02:24:22 PM »

Mr Hootie, is that article in a magazine i can get a reprint from? I'd love to read it, but the type is too messed up on my computer...

TwoTired · « **Reply #13 on:** February 13, 2007, 03:21:53 PM »

Magazine article should be made a FAQ submission IMHO.

Cheers,

Jugghead · « **Reply #14 on:** February 13, 2007, 03:45:17 PM »

Quote from: TwoTired on February 13, 2007, 03:21:53 PM

Magazine article should be made a FAQ submission IMHO.

Cheers,

agreed, this is great info and needs to be archived

Zane · « **Reply #15 on:** February 13, 2007, 05:53:40 PM »

Yeah - great article Sam! Thanks for going to the trouble of posting it.

Also an excellent photo biffta.

I'm motivated to post the articles from my 1976 copies of Cycle World on "fork fixes".

So should I put that over in FAQ's, or post it here, or both??

Just wondering.

Cheers all.

heffay · « **Reply #16 on:** February 13, 2007, 05:57:59 PM »

Quote from: Zane on February 13, 2007, 05:53:40 PM

Yeah - great article Sam! Thanks for going to the trouble of posting it.

Also an excellent photo biffta.

I'm motivated to post the articles from my 1976 copies of Cycle World on "fork fixes".

So should I put that over in FAQ's, or post it here, or both??

Just wondering.

Cheers all.

steved is taking care of the faqs... i spose we other mods could too as well.
but, you can post in the faq submissions which will be reviewed and placed in faqs if found worthy

i'd put that camchain article in the faqs but, i cannot read it either. better quality file?

bill440cars · « **Reply #17 on:** February 13, 2007, 06:13:01 PM »

Quote from: Jugghead on February 13, 2007, 09:11:58 AM

Hey bill!
I just looked at hootie's post with diagram, and since i just opened up the top end of my spare 350F motor ---see my: "When bad things happen to good motorcycles" post.
I know that they are seemingly identical. the dampers, guide and blade were the same, and when you look at the case, the adjuster is in the same spot and part E is in the same location. I would wager that yes, they are the same.
I just may have to apply that knowledge to my 350F!
Good luck to you all.

Hey thanks Jugghead, I saw your post and was gonna get back to you but, I got side tracked by some other stuff and I finally made it back. I agree about that knowledge applying. It is good to know that some things apply to several models. Take care and I'll catch you later on.

Bill

hootle · « **Reply #18 on:** February 14, 2007, 06:38:57 AM »

Guys,

Glad the article helped. Certainly takes the mystery out of it if you've never had the cases apart. I can't take credit for scanning it—it came from this guy's site:

http://www.mil-amax.com/ameyer/honda/

Nice site, lots of shots of a gorgeous bike...

I'd back up that it needs to go on the FAQ. (For those who asked, it looks like it comes from Classic & Motorcycle Mechanics, but there's no page number or month shown. Brit mag, but that's all I can tell.)

Again, glad it helped!

-Sam

Jugghead · « **Reply #19 on:** February 14, 2007, 08:22:30 AM »

The Original scans are here:
Page one:http://www.mil-amax.com/ameyer/honda/resto/400Fcamchain1.jpg
Page two:http://www.mil-amax.com/ameyer/honda/resto/400Fcamchain2.jpg
Page three:http://www.mil-amax.com/ameyer/honda/resto/400Fcamchain3.jpg
The text is slightly more clear that the repro scans hootie posted.

bill440cars · « **Reply #20 on:** February 14, 2007, 08:53:37 AM »

Hope it's okay, but I just had to post this 400F that was from the link provided by hootle.
Later on, Bill

Bodi · « **Reply #21 on:** February 14, 2007, 09:18:02 AM »

Good instructions for replacing the chain with a rivet link chain.
The adjusting method 2, requiring removal of the rocker cover and loosening the blade holder, seems a bit over the top to me.
Method 1 is a lot simpler and works very well, unless your adjuster pivot is chewed up and frozen solid. I've never found one that bad, gentle tapping down on the rod has always moved even stiff ones enough to quiet the chain.
I would advise anyone taking a 350-4 or 400F engine apart to replace the cam chain with an endless high strength replacement, and if you have a high mileage bike doing the change to a riveted replacement is advisable. I've yet to see a cam chain broken but I have seen some badly stretched original chains, this throws the cam timing off enough to affect performance enough to notice the improvement when a new chain is fitted.
A new chain will loosen up a bit in the first 100 miles or so and need readjustment.
You can change the cam sprocket if it's ever required, I've never found a badly worn one. The crank sprocket is part of the crank and not separately replaceable. Both sprockets are hardened I think, and don't seem to wear even with a stretched chain - maybe being oil soaked helps.

supersport_CB400F · « **Reply #22 on:** February 14, 2007, 09:19:15 AM »

Who would go to all that effort then paint it all yellow and put a motad on it! Not my cup of tea at all!

Bodi · « **Reply #23 on:** February 14, 2007, 09:22:36 AM »

The tank looks like stock canary yellow colour, I am not enamored of the painted fenders though.
These are the first set of alloy wheels I've seen that look good on a 400, most have too much "spoke" and look too bulky.

LoopsAndLogic · « **Reply #24 on:** February 14, 2007, 09:57:38 AM »

Wow! Thanks guys for all the help

You guys should check this sight out for the cam chain. http://www.lm-spares.co.uk/acatalog/Honda_Cam_Chains.html

Just make sure you ask them to include the rivet master link.

Yeah, I did the adjustment using the manual method and it worked great! But you still notice a little stretch in the chain from a very
quiet rattle that's barely noticeable.

Would you guys recommend using a Keyster carb kits?
And lastly, what would cause a lower intermittent clunking noise from the bottom of the engine at idle?

This site Rules

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Author Topic: CB400F Questions and Dilema's (Read 11398 times)

hootle

supersport_CB400F

Zane

hootle

supersport_CB400F