Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: z1100r on June 04, 2013, 11:36:04 AM
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Hello chaps,
I was here alot a couple of years ago when I corrected a terrible dis-service I'd bestowed my poor old 500-4. I recorded its resoration on here.
I have however become one of those thats just looks in from time to time.
Well to get to the point my Mother-in-laws gardner collared me the other day and asked if would be interested in getting his old bike going - he fancies a tootle round on it again.
"Hey that 500 looks great, would you mind having a look at a bike I've got..?"
"Yeah sure.. what is it..?"
"A 400-four"
"oh right, I used to like the Yellow ones"
"It is Yellow".
"Whats up with it.??"
"Nothing its just not been run since 1981".
"Yeah Ok I'll have a look at it".
Well bugger me....it must of been a mint bike that had only done 1,700 miles when it was parked in a shed. Its been relatively well stored, but not been turned over or even uncovered since 1981.
The good bits:-
Paint work is Excellent,
Chrome is really good,
All brackets, nuts and bolts etc still have their original plating and look new.
Master cylinder and caliper/disc look new, as does all rear brake gubbins.
Engine exterior, Dusty and grimey, but looks perfect underneath.
The bad bits:-
The brake fluid has solidified,
Clutch cable has seized solid....I mean solid, and throttle cables are stiff.
The baffle components of the immaculate original chrome silence poured out onto floor as a pile of orange powder.The bits that are left just rattle around.
Carbs slides are seized and inside the float bowls is an horible mess.
THE WORSE THING OF ALL though is that he has tried to kick it over. The inlet valves are seized/very stiff in the guides (too stiff for springs to return them), it must of started to whizz over then went clonk and locked solid.
2 bent inlet valves and 2 broken inlet valve guides, exhaust valves are fine, cylinder bores are perfect. When I eventually got the head off the inlet valves were all jammed down in the open postion.
Bottom line though is that with not too much effort this thing will look incredible for an original untouched 1979 bike. I mean fix these valves and strip the front brake stuff, buy a new clutch cable and free off the original throttle cables ( at least they move) and give ity him back to clean....wahhay. So I rang DS to enquire about parts and was surprised to find NO INLET VALVES (been on order for a year), have to order pattern Valve guides, clutch cable £25.
Hmm, need a secondhand head or just a couple of guides and valves. I used to have tons of this stuff cos i raced a Yoshi 460 but I only have 500/550 parts now - typical.
Will post some pics shortly when its been degreased and dusted off. I cant wait to have a go on it..!!
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Wow- Sounds like you know your stuff- What a find! Id go for an ebay head, as its just a few bits you want or someone on here might oblige. My new pipes (pattern of originals from DS) have arrived today- not bad considering I only ordered them Sunday- so I will be out dicking around doing that later on today..Have fun!- sorry, Ive got no engine bits to assist.
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CMSL in Holland has genuine inlet valves in stock, 18 euros each!
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I've been Saved...haha...A friend of mine just texted me from the IOM. He can sort me out a spare head as long as i fix the immobiliser/alarm on his Pan Euro as a swap. Excellent. trouble is he's not back until Saturday. I have no patience..!!! Doh. Still it gives me time to sort out the incredibly bad carbs. Petrol left in since 1981 has done them no favours. Inside of tank is probably not great either ..not looked yet.
Funny but I last rode a 400 four in the IOM. A mate lent me his customised black 1976 400four to go on in 1984. 2-4 seat, piper exhaust, fancy black paint job, I had a great time on it. I did a minimum of 2 laps a day rain or shine for a fortnight trying to learn the place. Blimey that was a long time ago.
CMSL list the valves but dont currently have any either apparently...and they only have pattern guides. Silvers told me that in a round about way. I'd rather tap some guides out of this spare head and pick the best 2 original valves from it i think. Knowing my mate this head of his will have stripped threads and be from a right old knacker. hehe. I'll salvage something I hope and retain the bikes original head.
Getting those circlips out the master cylinder is a bitch aint it...!!! haha. had to grind down my favourite long nose pliers to do it last night. Sulk.
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Getting those circlips out the master cylinder is a bitch aint it...!!! haha. had to grind down my favourite long nose pliers to do it last night. Sulk.
See http://www.sohc.co.uk/index.php?topic=4812.msg22294#msg22294
:)
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I would use pattern guides over tapped out original ones as they do loose some metal, albeit a tiny amount, and the new ones need reaming to size whilst the new ones may end up the wrong size after fitting.
If Dave Silver sells the part they are good to use as he won't risk his reputation on crap.
Why not use the second head complete anyway?
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I'll re-evaluate the situation when he gets back and I actually see the state of his secondhand head. Everything looks new on the proper head Bryan - exhaust studs etc, no broken fins, totally flat, and nice and shiny.
Sort out brakes and carbs tonight. looking forward to it.
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well I did the brakes...used my old 500-4 master cylinder in the end just to get them going....his master cyl looks new on the outside but my god not on the inside..all internal parts are rotted away. Caliper perfect. Swinging bracket perfect. Brake works perfect now.
So carbs...oh my god....they look brand new on the outside aswell, all plated shiny bits, screws and carb bodies as new. An amazing looking set of carbs....inside though, deary deary me. All jets blocked solid, float bowls lined with a layer of brown and green hard laqueor with a layer of grey powder sludge on everything. All primaries blocked solid, mains blocked solid, floats dont move, slides seized - an absolute nightmare. Struggled like mad to pull the main jets out. Horrible. And the smell. Gawd...!!! Good job I had all the drill sizes for the jets.
Done most of it now....but will have to remove emulsion tubes cos I just know they are going to be horible aswell. I guess they tap out upwards - cant remember. I need main jet and float valve orings....is 4 keyster kits the only way. I only need 8 orings...!
Clutch cable arrived.....£25 seems a bit steep for a fairly simple cable, but heh ho I aint paying. Lubed the throttle cables, perfect.
Nearly ready for this dodgy secondhand head. ;D
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The 400/4 tubes come out via the float chamber- usually with a bit of pressure from the main venurii from you finger! Yours my friend, will need a darn good soaking in carb cleaner
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Well after a ton of effort...carbs all done except main jet O rings...As I am always searching for tiny o rings I have bought a large selection of viton o rings between 3mm and 6mm ID of various sections from 1mm - all less than £20. Wont be here until next week. Should have rest of bike ready by then.
Carbs came up surprisingly well, they look very good on the outside and as good as any other set I've seen on the inside.
held up camchain and kicked engine over last night until oil spewed from barrel feed holes. Didn't take long.
All looking good ....come on matey with the head (the Senior is today so he should be back tomorrow). ;D
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Back on the case..... my O-rings arrived...4mm id 1mm section seem to do the trick perfect.
My mate turned up with the head...Firstly its a black painted mess...its been 'chiselled' off its previous engine, gas flowed by an idiot, and half the exhaust studs are snapped or stripped. Oh and a Broken fin at the front...valves and guides seem good though, and not a mark on cam bearings...strange. So a quick wash down and both heads in the oven tonight for valve and guide swap.. Should be riding this by the weekend. Will knock out the broken ones first just to see what happens and how dodgy they are to do.
Must remember to take my camera in the garage tonight.
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Well valve guides were no problem...oven on 220 and tapped them out...cooled em off and bumped them back in the proper head...all done in minutes and real easy.
Bike ran like a bag of crap though. Had washed out tank and thought all would be OK. oh no it wasn't. Mesh bit had rotted away on tap and tap was blocked solid with crap. Ran bike on temporay plastic bottle for a while but still crap. Carbs off again to find nothing wrong until i happened to notice quite by accident then when blasting air line down main jet hole on 3 of the carbs air was blast out the back brass pipebut on no.2 carb nothing. Drills out again. THat fixed it. Balanced carbs and away it went, cruising down the road and sudden mega racket. The back end plate of the exhaust silencer blew apart and al the contents flew out. A few miles later and she ground to halt again due to crap comming from tank blocking tap. Shoved a cam chain and load of nuts and bolts in tank and shook it about but not much crap came out...still doesn't take much I suppose if it goes down the tap. Gotta wait for a new tap and an airfilter now. I cant tell how its running really with that noisy noisy silencer.
By the time I've finished this thing is going to of cost a few quid.
Battery, silencer, sprocket set, oil filter/oil, clutch cable, master cylinder kit, head off for valves etc, hours and hours on carb cleaning, airfilter, petrol tap. It has to be a labour of love dont it.
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£100 for a pattern silencer from DS..mind you thats nothing compared to 900 quid odd for the original pipes holy crap.
I went up my loft to my spares supply. I knew a while ago I had bought a couple of reverse cone shortie silencers for my pair of 500 brit singles and they came with multiple collars to fit most sizes of pipe. Cost £27 each.
Well talk about being made for the job...it looks and sounds lovely and fitted a doddle. Another £25 to this guys bill though. I'm guessing he's going to get a £300 bill for putting this thing back on the road. Does that seem reasonable considering all the work and parts, I think so. He's on a bloody cruise for his Ruby wedding so not been able to confirm the spending. I remember another of my mates mate only paying £300 for a whole running reasonble 400 four not that long ago. Oh dear. This is an exceptional specimen though. Should have a proper silencer really but he can buy and fit that himself.
Its just sitting there waiting for some more DavidSilver 'gold' to arrive at the moment. Will go up and give it a clean and have a photo shoot tonight. Its even got its original Bridgestones. Scary. Lol
Blimey the mega's have gone up.
http://britishbikebits.com/unbaffled-universal-megaton-reverse-cone-chrome-silencer-1-3-4-1-3-8-inlet (http://britishbikebits.com/unbaffled-universal-megaton-reverse-cone-chrome-silencer-1-3-4-1-3-8-inlet)
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Sounds a bit like mine - it had 1,800 miles when I got it, now only 2,200...
My silencer seems OK after a long lay-up. Some bits have come out but the end plate seems sound and it seems to work. Of course may not stand up to real use as its only been started recently. Down pipes/collector could use a rechrome but sound. Everytyhing else is fine.
I also have original tyres (not fitted!)
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Tom,
Sounds very similar. On this one the header pipes are mint, actually look brand new. The silencer though showed bulging on the outside where the baffling was spot welded in. The first thing that happened was a large hole appeared in the recessed back bit next to the exit hole. The insides had allready well rusted and collapsed - you could here them rattling about, and exhaust was noisy. I was giving the bike a bit of a gunning when the sound levels rose to unbearable and the whole lot disintegrated.
Wheel rims are good, spokes are average, chainguard is mint, all handlebar controls, headlight etc mint, mudguards very good - not polished them up yet to see just how good. Paintwork could be new, not even a scratch. Engine paint not as good as I first thought. All ancillary components and brackets really good and everything comes undone no problem.
I cant remember how fast these things go, speedo said 90mph upright against wind and it seemed about right. Took a while to get there though. Acceleration is tame and requires lots of revving. Tootling about upto 60/70mph is absolutely lovely (I must be getting old). I'm 5'11 but I still find it quite comfortable - especially compared to my Thunderace.
I do have a soft spot for these SOHC bikes, I raced a 550 and won a club championship on it, my mates had them as road bikes and they were all thrashed to absolute near death racing RD's but unlike the RD's - no blow ups that I can remember. They were 460'd, yoshimura'd, piper'd and ace bar'd. fancy seats , crappy paint jobs, culminating in total abuse. I bet most of them would still go with a little tlc. lol
Looking forward to a quieter less eventful ride in a few days. No more 'carb tuning' required I hope, it should be back to how it should be. A smooth quiet pleasing little thing.
I wont want to give it back.....he wont use it...I bet its on Ebay in a few weeks.
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I agree with the speed scenario- mine got considerably more mileage that yours and its been stripped many time- it like lots of revs and whips up to 70 quite easily- but that's enough for a 35-year old girl- I don't want something falling off or dropping. Off for MOT tomorrow as done enough fettling and need to ride it legally :-) Ive a few newer bikes to ride that will take more of a thrashing.
400/4s do like revs and mines ok on tick-over, a slight hesitation below 3k and bloody marvellous over that - I don't take it over 7.5k
Very amusing reading the re-build- nothing ever goes smoothly , especially carbs and fuel.
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You are right there...!!!
Got all the bits from Silvers - after another trip to FEDex building cos i wasn't in for delivery pain in the ass - and fitted everything within 30 mins. Zoomed off out for a ride but its still not right. Its not bad but I remember the 400's Ive ridden in the past being super smooth with perfect carburation if they had original airbox. This has a noticeable glitch on initial pick up. I wasn't happy with it so carbs are off again. There is definately still a problem somewhere most likely in the primary circuit.
Everything else is done, I filled it up with fuel last night and came out from paying to a little gathering that had formed around it. Had a 10 minute laugh and a joke about the old days with some guys that obviously remembered their 400's very fondly. I never actually owned a 400 four I was always a 2-stroke nut (still am).
So the carbs are on my bench AGAIN. Initially they were very bad and as such I went over and over them but I must of missed something. Doh. All good fun eh. What else would I be doing - "couch potatoeing".
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Well, mine passed its MOT but I have to admit- my one ALSO has a slight hesitation picking up- its ok after 2.5k- so ill be interested to read if you nail the problem.
Ive another set of carbs I used a month ago- stripped, completely re-jetted using kits- the only thing I didn't do was separate them- so I still have some O rings left over. The bike DIDNT like them- far worse hesitation and an annoying tick-over drift like they were leaning out- would drift on tickover up to 2k, then settle after a blip. I have a balance between the set that's on there which are a bitch to start from cold- and the other set with the poor running.
Hey Ho- keeps us off the streets but in the wifes bad books with the smell of petrol in the air over the house of a weekend!
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Well in both our cases there is a blocked hole somewhere. This one doesn't settle to Idle correctly either. It revs high for a while sometimes before plummeting to stall. I know what this is and have fixed it loads of times in the past but I cant remember at the moment. Hahaha. I'll think of it later. Its basically lean on the primary circuit. must check how the fuel is supplied via that circuit, (wether its a small hole in the bottom of the venturi etc). I did rely on my airline cleaning these passages (maybe it didn't).
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Yep. did the same and plenty of carb-cleaner- some ended up in my face due to the over-exuberant use of the air-line. Carbs are great when they are working but not so great when they are 35 years old.
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Well I got that wrong....It was seriously rich on the primary circuit not lean. I still dont know why. 2 turns on the air screw as my manual suggests leaves it 'hunting' away with sooty black plugs. 3 turns and its settled down to a nice throttle response, even tickover, and much cleaner plugs.
I noticed when running it on my plastic bottle that as the fuel runs out (less in float bowls) it switched from eratic and lumpy to running lovely. Float heights are set at 21mm as manual. Its a strange problem. When cold the bike ran great, no choke was ever neede though. It all suggests a blockage in the air feed to the mixture screws, but i cant find any problem.
Turn your fuel off and see if yours improves (cleans up) as the petrol runs out (after say a minute on tickover). Makes a huge difference to this one. Suddenly it will purr at 800-1000 rev perfectly. Turn the fuel back on and it starts the lumpy horibleness again after a short while. The weird thing is that its all 4 cylinders affected exactly the same. I could accept one carb having an issue but not all 4 with exactly the same problem. It like someone has put a pin hole in all the floats. haha
I've not bothered connecting any throttle cables or airbox rubbers while I sort this so I can get them on and off quick. They are off again this afternoon for a final inspection and to set float heights to 22mm.
At one point last night an awful lot of 'steam' was comming from the engine breather, mind you I had had it on tickover in the garage on and off for about 4 hours - engine was very hot.
Final go later today...on 3 turns out its very good, so if I cant find anything else thats what I'll leave it at and give the bike a good whizz around - do hundred miles on it and see if things settle down.
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oh another thing....that foam breather filter at the bottom of the airbox...blimey that was just wet oily dust...it was horible.
Hmmmmm.. Ive just had a search around and it seems this is a very common problem with these carbs. It has to be floats. It has to be. haha. Well fuel levels in bowl..arrgh...I'll check that with a tube later.
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Its a shame the float bowls are not glass or plastic! I remember in the 70's when NIKI carbs first came over here, in my Anglia 1500/1600 (the latter for the rich-kids!)- the Nikki was a good cheap substitute for the Webber 28/32 twin-choke and 1/3rd of the price.
Anyway, back to the bikes... Ill be interested to know how yours runs on 3 turns out (the Haynes says 2 1/2, Ive had mine set at that but di once have them at 1 1/2 and it ran poor) Ive a feeling mine will start bnetter as I treated it to a full fuel tank yesterday as it had passed it MOT- If that's the case and it does start better from cold- then again, Ill have to remove and empty the tank as I put a picture of my fuel filter on another page on this site last week- that's what it looked like 2 years ago when I first got the bike running- and Ill be doing the cam-chain and nuts/bolts dance around the garden.
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Float height seems a controversial issue on the 350f and 400f. People that have taken carbs off bikes that have not been tampered with previously have all measured the float height to be 24mm using the exact method I use (Vernier caliper set to float height value and float just resting on spring tip but not compressing it). It was imposible to tell what they were originally because they were seized solid on these carbs. So far I've read about 3 people stripping std 350f previously unmolested carbs and finding float heights to be 24mm. I've also read about loads of problems with rich slow running from people who have rebuilt carbs and set them to 21mm.
So I'll set them to 24mm later and see...24mm so rings a bell, I sort of remember an issue like this in 1983'ish before I had a manual when i raced the 460. yeah 24mm..Thats right..!!!
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I'm having a similar issue with my 400 - runs cleanly when cold but after the engine has warmed up it bogs down when you pull away, needs revving more than necessary to get moving but when the revs build up it pulls strongly and revs freely. If you shut off the throttle when riding along then open it again you can feel a hesitation, then the bike accelerates normally. I was going to have a play with the mixture screws and after reading this thread it looks like I may have to clean carbs again or check float heights. @ Z1100R - would value your opinion on this as you seem to have a good knowledge on the matter.
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This is doing my swede. Those dammed carbs. I cant understand it, i've had them apart so many times now its stupid. There seems nothing wrong with them. The bike pulls and drives away absolutely perfectly when cold or warm but as soon as it gets hot the problem starts. The exact problem Dan and lots of others have.
What I cant fathom is that its all 4 carbs. Plug chopping the bike flat out and at all speeds the plugs are the most perfect light tan colour. Leave it ticking over though and they go sooty black.
There is one thing of concern and that is when the bike is hot an awful lot of steam comes out the breather. Way too much. So I pulled the airbox breather pipe off and left it dangling, things improved, but the steam was still pouring out. It suggests that there is blow past on the pistons and maybe i have a stuck ring or something, but this thing runs so smooth and doesn't smoke at all.
The air screws seem to have little effect past 2 turns out yet if if i screw them in to 1 turn the bike will stall. 3 turns or even 4 turns makes no difference. Normally twiddling an air screw makes the engine speed up or down.
I have to say its been getting better every day and it is now quite nice but its definately still there.
Floats are 24mm, airscrews are 3 turns. Number 2 carb does occasionally overflow. Its always number 2, the others are fine, so it looks like I'll have to re-examine no2.
Oh well more head scratching....hahaha
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Crikey, I'm just doing my carbs because mine has always had the same problem! I'd be interested to see how you fix it. I always thought it was just cruddy carbs and a dunstall decibel pipe.
People are saying two different float heights, 21mm and 24mm. Is it possible that 21mm is the height the fuel should be from the top of the float bowl, and 24mm is the height from the float bowl top to float bottom that should give that figure? Obviously the float bottom will be below the fuel level. Maybe over time the fuel soaks in, makes the floats sink and so you get a high level and richness.
You can see the actual height by attaching a clear pipe to the float bowl and holding the open end above the top of the bowl. The fuel in the pipe will be the same level as in the bowl, so you can measure it. Shouldn't be too hard, you've got drain screws in the bowls already.