Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: ManicGTI on April 28, 2015, 02:21:34 PM
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EDITED title to current status.
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Ok apologies for the lengthy post! I'm having difficulty coaxing any kind of life out of my CB400F. Not a massive surprise as it was last taxed on the road in the mid-90's!
I'm really looking for a bit of guidance on an order of attack...what to check next and in what order, all advice welcome!
Intro thread and background to the bike: http://www.sohc.co.uk/index.php/topic,7399.msg44632.html#msg44632
I understand that there's a ton of things that need checking over before the bike will likely run 'well', but as a starter for ten I was expecting for it at least to attempt to fire up...It's turning over but it's not even trying to splutter into life :/
Status so far:
FUEL SYSTEM:
- Carbs were gummed and locked up. Following advice on here I left them in hot water to loosen, then stripped and cleaned them with carb cleaner, including jets etc. Replaced all O-Rings along the way.
- On reassembly the bowls leaked badly. I've bought a rebuild kit (non-genuine) and replaced the Float Valves and pins, but left all the other parts as the OEM ones at the moment. On reassembly (3rd/4th time lucky!) now only one of them leaks.
- Tank cleaned, new petcock, fuel hose, in-line mini filter and some fresh fuel.
- The carbs are roughly synced on the bench, but not balanced properly, just rebuilt as they were. I have not put the airbox or filter back on.
ELECTRICAL:
- Checked Continuity across the starter circuit. Clutch switch is duff so I have bypassed it with a jumper in the headlamp for the time being, now cranks on the electric starter perfectly fine.
- Checked continuity of Ground side of Coils and Engine Stop Switch circuit.
- Both Coils input sides appear to have a resistance of ~ 5.2 Ohms. A couple of the HT leads havd kneckered ends so I trimmed them a little and refitted the Caps.
- Battery is new but admittedly undersized as I was planning on relocating it. Its an AGM Fireblade battery, I have it sat on an optimate so it has full charge.
- Brand new spark plugs fitted. All four are getting a visible spark when I crank with teh plugs lying on the head.
My feeling at the moment is that no fuel is getting into the engine, I can't see any fuel on the plugs. However, I've tried cranking it with some easystart into the carbs and not even a splutter.
TO DO:
- A 'proper' compression check, adaptor for my compression tester is ordered.
- Check static timing, although I cant see why this would be out.
Other things to check?
- Valve clearances, will this make a difference at this stage of things?
- Pull the carbs, clean again and replace idle jets etc with those from the rebuild kit?
- Anything else to check on the ignition system?
Dave
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Have you checked that the points are actually connecting and opening as corrosion would stop the former and age the latter
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I would have thought the points were ok since the plugs are sparking.
Two things have caught me our in the past...
Make sure the points cam is not 180 degrees out and
Check that enough air is getting through.
Since it won't start, the plugs should be covered in petrol. If they're not then why not.
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Thanks for the replies guys, I started this thread to re-inject some enthusiasm as I got thoroughly pissed off with the whole thing at the weekend.
I've had the cover off and the points look in great condition, no corrosion and they open/close aif I slowly crank it on the kick starter with cover off. I haven't adjusted them as I am getting spark to the plugs. It's the NipponDenso setup, I'll dig out a photo.
- Points Cam, thanks I'll have a look at this. Any way to check visually?
- Enough Air getting through - I haven't refitted the filter or airbox so there's no restriction other than the throttle sliders.
Dave
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(http://images.tapatalk-cdn.com/15/04/28/5f1ff30d51a8f4fd2ab88446ec6970ec.jpg)
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The LH points (blue) power plugs 1 and 4. RH points (yellow) power 2 and 3.
Considering 1,4 for a moment...
When the points open, the coil for 1 and 4 should make a spark. This should occur when F1,4 shows through the timing hole in the points plate.
Once 1, 4 is timed, then do 2,3 as it's on a sub plate.
If and when you get it going, beg or borrow a strobe light to get it spot on.
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Thanks, intended to have another look this weekend but haven't had the time I need!
Float heights- I did set these, and redid after changing the float valves. I'll recheck, hopefully the leaking one was just a mess up on my part.
Choke- Yes, used the choke, tried in all sorts of state of throttle and choke.
Emulsion tubes- Yes, pulled and cleaned it all. Having said that, I'm inclined to pull the carbs and go over them again to be sure. A colleague at work has suggested I use the full rebuild kit, despite they're rep for not being great quality it should get it running and can always swap back in the OEM parts afterwards.
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Adaptor for compression tester has just arrived, so I'll get on that and check the points timing.
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Thanks, intended to have another look this weekend but haven't had the time I need!
Float heights- I did set these, and redid after changing the float valves. I'll recheck, hopefully the leaking one was just a mess up on my part.
Choke- Yes, used the choke, tried in all sorts of state of throttle and choke.
Emulsion tubes- Yes, pulled and cleaned it all. Having said that, I'm inclined to pull the carbs and go over them again to be sure. A colleague at work has suggested I use the full rebuild kit, despite they're rep for not being great quality it should get it running and can always swap back in the OEM parts afterwards.
I wouldn't dismiss using the Cruzinimage carb kits due to low price. I replaced all the bits in my 400 carbs a few weeks ago with the Cruzinimage ones and the carbs are working beautifully
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Before you do a total strip spray a small amount of ether or "Easy Start" into the airbox and see if it coughs, if yes its carbs or settings if not its electrical. NOTE THE EMPHASIS IS ON SMALL
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Where do you live, one of us on the forum may be local to you.
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Mine at least attempted to start but wouldn't run when I reassembled and installed the carbs, once I used the settings in these diagrams it solved the problem and ran fine, I'm not saying it will solve your problem but it's a good starting point.
[attachimg=1]
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Fantastic, thanks for those!
I'm based in Balham, SW London. Thanks for all the input folks, I'll give the above a go and see where it gets me, including pulling the carbs again and attempting to set them up better.
Due to unforseen circumstances I had to spend the weekend away from home, hoping weather clears up and I can get some time in the evenings on it as May is super busy and moving to North London in June!
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Was it just one picture attachment to your post Bodd?
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Was it just one picture attachment to your post Bodd?
Yes, I clipped 2 diagrams from the supplementary manual pdf and made them into 1 graphic. PM me your email address and I will send you the whole file.
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@ManicGTI I am in N1 and would be happy to help if I can be of any.
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Coincidentally I'll be moving to N1 (near canonbury) in June.
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I tried sending the pdf's to your email ManicGTI but your email client keeps returning them saying the account isn't set to receive attachments so I have uploaded them to my website, if anyone else wants them too you can download them from the link below, there are 3 files in the zip all in pdf format, they include the Parts manual and 2 supplements.
Download (http://www.skylinesoftware.co.uk/400four/CB400.zip)
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Download link works perfectly thanks, strange that gmail won't take it!
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After all your helpful comments I still haven't had a chance to take a look at it...I will get there!
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Well, after a hiatus from the bike I've managed to get outside and spend some more time on it.
Compression isn't looking good at all.
Dry Compression: 105, 0(!), 125, 110.
Wet: >200, 5(!), ~160, >200.
I did three of them with some oil and they increased massively, with the exception of the second which blipped only a little.
So I'm assuming from this that I have a major issue on Cyl 2 (Where cyl 1 is the 'choke' end), Ring, piston or knackered valve/seat?
From my trawls across the web, It should still be 'attempting' to start given the pressures above (with exception of cyl 2!), even if they are less than ideal. So I think I need to take a look at the carbs again.
I have to admit I'm starting to regret taking on a bike like this now, I just haven't had the time to give it he attention it needs :/
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Are you getting the bike up to Canonbury soon? We can get together, draw in our breath and rub our chins over it...
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So happily I've now moved to Canonbury...Sadly however the bike and all my tools are now in a garage in Hertfordshire as I don't have the room for two bikes here. If you see an Orange Street Triple R around say hi, that's me!
I'll have to sort a trip up there at some point to do some more detailed diagnosis. I was very close to buying a replacement engine from bikepusher but decided there's no real loss in tearing down what I have before I do anything silly. Head off first to inspect the valves, then poss the cylinder block off for further inspection. Down the rabbit hole...
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Head and barrels off is easy on this bike and will tell you a lot. Out of interest whereabouts in Hertfordshire?
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It's up in Cuffley, my Sister is living there and has an empty garage, well it was empty...now it's full of my stuff!
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Well at least the garage is being put to good use ::)
I can get there fairly easily if you ever want a second opinion... my bikes are in Southgate Road btw
Cheers
Tom
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Haha! Now I'm really sad I don't have the CB down with me...I'm only just up on Mildmay Park Rd. Thanks for the offer, appreciated, practically I think it'll be a few weeks until I can get up there to have a look anyway.
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So some progress! Good and bad news, pulled the head and cylinder block yesterday.
- Exhaust Valve on cylinder 3 has as chunk missing, so that's the source of the low compression. Tempted to clean it up, get a replacement Valve and lap the valves back in rather than a full rebuild.
(https://lh3.googleusercontent.com/-uEP7966vWRI/VaLirm2pivI/AAAAAAAAMFk/qB-WyzmirSE/s912-Ic42/P1010017.JPG)
- Piston on Cylinder 1 had a broken ring which seems to have damaged the Ringland, so it'll need 'at least' one piston.
(https://lh3.googleusercontent.com/-9E6gw6r5GnE/VaLWT0LFfvI/AAAAAAAAL-g/ZptHEIru3dU/s912-Ic42/P1000962.JPG)
All the pistons are Honda marked, and none of them have markings on the crown to show oversize. There's some marks on the outside of them, and a few length ways marks in the bores. Nothing I can feel with my nail though.
I've taken images of all the pistons: https://drive.google.com/folderview?id=0B3qBPnS1cCGlNktETm9xbXNRN00&usp=sharing (https://drive.google.com/folderview?id=0B3qBPnS1cCGlNktETm9xbXNRN00&usp=sharing)
Any views would be appreciated, advice on checking that they're in spec?
Does anyone know of an engine place in London (Pref NE or SW) that could take a look at my cylinder block and pistons before I decide where to go next?
If I get it honed would I need to change all pistons and rings?
(https://lh3.googleusercontent.com/-p2JMcIjZPeg/VaLebEbDdzI/AAAAAAAAMDQ/LwJ3iE_blEk/s1024-Ic42/P1000996.JPG)
(https://lh3.googleusercontent.com/-mRMqYaLQjC8/VaLkzuSW7aI/AAAAAAAAMHI/NQiTC04TD6g/s912-Ic42/P1010003.JPG)
(https://lh3.googleusercontent.com/-wg_BoT3rd4s/VaLipCDz9iI/AAAAAAAAMFc/RTJV0BKXnUA/s912-Ic42/P1010015.JPG)
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Any skimping on a engine will bite you back later. What is the cam shaft like ?
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From what i can see that is a set of exhaust valves not just one, replacing just one piston along with 4 sets of rings is a mimimum but a full set is better and as oversize cost the same as standard why not rebore if you can see marks, just my opinion its your money to spend how you wish
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Or go mad and get a 460cc bigbore kit from cruizinimage, a fairly good quality kit, and a lot cheaper than genuine parts!
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Yeah I pulled all four exhaust valves to take a look at them and give the ports a clean. Aside from being filthy it looked in fine condition. I'm hoping my car valve compressors are the right size to get them back in again!
Don't get me wrong, I'm happy to do what work is required. But I don't subscribe to blindly changing everything. I'd prefer to get a view on the condition of what's there, if its scrap then so be it.
Having said that...I had spotted the cruizinimage kit on prev threads, could be a good solution. Any downsides aside from losing the taper to get the rings in?
Sent from my Nexus 5 using Tapatalk
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Any good machine shop will do the boring and reinstate the tapers.
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Ah ok, I had thought from various threads (http://forums.sohc4.net/index.php/topic,96453.25.html) that the overbore meant there's not enough meat in the liners to have a taper with the 466cc kits.
BikePusher has an engine for sale at the moment as well...could be an option.
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BikePusher has an engine for sale at the moment as well...could be an option.
Before anyone else jumps in... you are joking right?
:)
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BikePusher has an engine for sale at the moment as well...could be an option.
Before anyone else jumps in... you are joking right?
I can't find much reference to bike-pusher on the forums, is there a reputation I should be aware of?
It's not my preferred option as I'd like to solve it myself. although looks like cruzinimage isn't selling the piston kits to UK at the moment.
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All I remember of Bikepusher was him asking why I was even bothering with my café racer build ::)
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Dave
bike-pusher is a breaker of 400Fs and has a healthy business on eBay. He joined these forums for a while and if you ask me it was only a matter of time. You can't be both poacher and game-keeper and indeed it all went sour with other members.
Spookily I flogged some furniture on ebay and the husband and wife team who came to collect it - he knows bike-pusher. Says he's a top bloke but tbh from what I could tell she was the one with the lights on and anyway if you're a dealer (viz pusher) you're a top bloke, right?
Anyhooo, sent you a PM. Looks like your bike broke a ring and this has taken out the exhaust valve as bits were expelled. Mild seizure marks on some pistons. Must be a rebore surely... Engine likely thrashed and should be stripped completely ::) On the bright side the bottom ends are built like a brick outhouse. Probably alright but you'd want to get in there, right?
Will ask my local friendly bike shop about engineering outfits.
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Sounds like a familiar story tbh, have seen similar things on car forums.
Actually the broken ring was on a completely different cylinder to the broken Valve. It appears to have knackered the ringland on that piston in the process. Not that that helps!
I'm going to work out what to do with the cylinders before I think about the bottom end. Will see how much time I get.
All the input really is appreciated, thanks guys.
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Re: 'bikepusher' ..... Well me included peed him off a bit and TBH it was because I can't bear to see really nice bikes broken for parts, which is a bit hypocritical of me really because deep down I know I have bought really nice parts off nice bikes which should never have been broken up.
He starts stuff pretty low and daft bu**ers pay silly money for tiny bits and he rubs his hands together with glee but some stuff looks OK and goes for a reasonable price sometimes, like engines and wheels etc that he sells and the description is pretty honest.
I too need to track down Cruzinimage, as I want to buy from them directly and have them shipped within Japan.
Ash
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Hi AshimotoKO,
You could try---------cruzin_kx4305qgj@members.ebay.co.uk---------I can't be sure but I think the answer comes from Japan
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The reality is, mine is not that 'really nice' bike and I'm not going to pretend otherwise. I'm taking the approach of 'getting a bit more life out of the old girl' and have some fun doing it, rather than aiming for a ground up resto. We'll see how it pans out.
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OK I popped into Burwin Motorcycles this morning where I regularly go for tyres and MOTs to ask if they know of any engineering firms in norf London. "Not anymore" was their reply. Best they could come up with was http://www.galeacamchainservices.co.uk/ in Wickford. :P Not local but may be reachable...
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Thanks for doing that Tom, appreciated. These guys look worth a look as well, HTHoward in Slough: http://www.hthoward.co.uk/engine-machining-services/motorbike-engine-work/
I've had no luck looking for somewhere more convenient either :/