Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: iansoady on March 26, 2022, 10:39:27 AM

Title: Honda CB250RSA tips?
Post by: iansoady on March 26, 2022, 10:39:27 AM
I have now sold the X-max - losing a fair amount but better for it to go than hang about - and have my eye on a 250RSA "project" - this one. It was up for a week with the same starting price with no bids and now nearing the end of its second attempt. Hoping to pop up to Stafford tomorrow and have a shufti. Any tips on what I should be looking for - I know about chocolate cylinder heads but other tips would be helpful. I'd be planning to move it back closer to standard as exhaust wrap doesn't float my boat. Thanks in advance.....

https://www.ebay.co.uk/itm/144466625018
Title: Re: Honda CB250RSA tips?
Post by: themoudie on March 26, 2022, 10:47:47 AM
Morning Ian, sorry cannot help with "tips" as I have never owned one, but good luck if you do make the trip. Bill
Title: Re: Honda CB250RSA tips?
Post by: SteveC#222 on March 26, 2022, 11:09:23 AM
tevie54 was the man for 250RS info but he hasn't been around lately :-\
Title: Re: Honda CB250RSA tips?
Post by: spooky on March 26, 2022, 11:19:37 AM
Is the cb250 rsa the electric start version ?
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 26, 2022, 11:26:52 AM
No it's kickstart. I have read on the web (therefore completely unreliable) that the e/s versions were somewhat troublesome.
Title: Re: Honda CB250RSA tips?
Post by: mthee on March 26, 2022, 12:33:47 PM
Has the subframe been chopped? With scrambler projects, it's often the first thing that gets done. Best of luck.
Title: Re: Honda CB250RSA tips?
Post by: spooky on March 26, 2022, 01:03:20 PM
Has the subframe been chopped? With scrambler projects, it's often the first thing that gets done. Best of luck.

looks like it has
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 26, 2022, 01:04:39 PM
That would put me off. I'm having difficulty getting to see it so probably as well to leave this one alone. How could I tell if the subframe has been chopped?
Title: Re: Honda CB250RSA tips?
Post by: 500 T C on March 26, 2022, 01:20:44 PM
Hi Ian,yes I have owned 2,the best 250 ever made by Honda.   A no frills 250,will knock spots off a 250 wet dream.
But saying  that its a 4 valve head and I would guess this would need attention.     Highly reliable,if used daily, can be a sod to start if left to stand.The gear lever pivot lug is vunerable to being broken off, when dropped.
The one you are looking at ,looks as thou ,its been messed around with.Some hipster upstart,chopping the mudguards around and bandages around the exhaust pipes,and the seat is in a mess.Seller hoping to get a cool price,because it looks "cool".
Also they do use oil. Nice thing is the the crankcases split horizontally.
  Judging by the pictures ,I would not offer any more over 4OO for it,or spend another £1000,if you  find a better low milage example.Hope  this helps.
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on March 26, 2022, 01:48:04 PM
I owned one from new on a W plate, so same model as the one on fleabay. Had it for three years (if memory serves) did about a million miles on it. Then sold it to big bro who used it to commute to work on for a few years. Honestly can’t remember the eventual mileage we collectively put on it but it was a LOT. That bike NEVER missed a beat. Truly brilliant little 250. Oh.. and yes they would knock the spots off a wet dream😉
Martin (XBALLY) still has one and rides it so you’re probably best putting a shout out to him.
Best of luck with it, keep us posted 🤞
Cheers, Michael
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 26, 2022, 01:54:22 PM
Yes, I'd like to make whatever I buy into something more like original although I expect I'd lose the horrible headlight, indicators and clocks. Exhaust wrap? never understood it myself and would expect to be spending several hundred on exhausts / silencers. I just want a bike that's nice to ride and doesn't make me look like an idiot riding it - tall order I know!

THat one will be MoT and tax exempt which is a plus. I am communicating with the seller so we'll see what happens. If it doesn't get any bids I may make an insulting offer but I don't expect he'll go for £400!
Title: Re: Honda CB250RSA tips?
Post by: CrazyFrog on March 26, 2022, 04:47:55 PM
I can't think of his name Ian, but wasn't the lad who used to post on IKBA and worked at Draganfly an expert on these?
Title: Re: Honda CB250RSA tips?
Post by: 500 T C on March 26, 2022, 05:26:09 PM
           The first one I had ,the previous owner said the engine was  vibrating,it was something to do with an engine bolt ,I found missing and the bike only done 11K on the clock!
  Im sure new, the RSA 250 was £799 and the wet dream £899,hundred pound more ,for an extra pot, electric welly and slug performance.
          Then Honda made a newer version,as usual,not as good,KISS,did not come into it.(Keep It Simple Stupid)
Title: Re: Honda CB250RSA tips?
Post by: xbally on March 26, 2022, 07:37:04 PM
Well yes I've had a few of these and IMHO great little bikes. Best feature is the extremely light weight and smallish -but not too small size. I'm about 5 '11 ish and it does feel a bit small but I don't care as it's so easy to ride.
They do tend to be a bit snatchy being a single and chain and sprocket wear can be high. The cush drive on the RSA (kickstart) model can be a pain if worn. The bushes are hard to replace but I think you can at least get them now-at one time they were either v expensive or NLA even from Dave Silver. There's a large washer shim which takes up the play on the rear sprocket and this can be missing causing more chain sprocket probs.
The RSD (electric start) has a more conventional set up with cush drive rubbers which are easier to obtain and replace. And yes the starter can cause problems. A mate of mine had one in the 90's as a ride to work bike and he had trouble fixing the bust starter motor.
The gear linkage can wear resulting in a lot of slop but mine still worked ok.
Mine also had a problem with corrosion of the frame. I think it will be documented on here somewhere-I had to get a mate to weld it up. The clue was when the kick starter wouldn't retract properly and was hitting the footrest hangers IIRC.
My first one only cost me about £35 -about 15 ish years ago.It was high miles but ran well and just needed a few parts and some fettling to get it back on the road.
Oil can and usually does leak a bit from the rocker cover. My mate stripped it all and applied some form of epoxy but it still drips a small amount occasionally which irritates me as a Honda - albeit a 40 year old one should never leak oil! Mine has been MOT exempt since last summer and I believe tax exempt from 1st April. Yes they do use a bit of oil and there's no filter-just a screen under the clutch cover.
I think you can get pattern exhausts but silencers can be a problem although if you're not fussy I think something can be made to fit.
You may know of a British bike place in Redditch which advertises on Ebay and may have something to fit? Motad used to do a 2 into 1 and they turn up occasionally. I managed after waiting about 5 years to get some second hand originals from D & K for not too much money about 7-8 years ago.
Hope this helps.
As for that one in Stafford-would be OK if you can get it cheaply enough but will cost a bit to put back to standard. Mine had a chopped end off the frame under the seat but the PO had the cut off frame section and a mate fabricated a joining piece and welded it all back.
 
Title: Re: Honda CB250RSA tips?
Post by: mthee on March 26, 2022, 11:33:39 PM
Here's a pic of his bike against a complete frame. It looks to me like he's only cut the undertray - flush with the end of the frame rails.  Ask him for a pic from the rear to be sure.👍
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on March 27, 2022, 08:33:27 AM
Looking at the pics, I personally DON’T think he’s cut the frame. Obviously I could be wrong but looks like he’s mounted the indicators to the rear of the frame rails. Plus looking at the “build” generally, he doesn’t strike me as being the type of bloke that owns an angle grinder.....or even a hacksaw come to that 😉😼🤷???🤦???🤦???
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 27, 2022, 09:23:48 AM
Many thanks again all especially Martin for the comprehensive rundown. I wanted to go & see that one but he's not available today which is the last day of the auction. If it finishes with no bids I'll see.

Came across this as well which looks rough but cheap.  https://www.gumtree.com/p/honda-motorbikes/honda-cb250-rs-/1426750944 (https://www.gumtree.com/p/honda-motorbikes/honda-cb250-rs-/1426750944)    No compression? Could be all sorts. I am looking for a project rather than a running bike.

The place you refer to Martin - the classic bike shop - is indeed in Redditch and has a good range of bits & bobs including exhausts for the Honda. It might look - and sound - nice with a pair of Goldie silencers...
Title: Re: Honda CB250RSA tips?
Post by: spooky on March 27, 2022, 11:27:10 AM
Sounds to me like you need a Conda 250 !
Title: Re: Honda CB250RSA tips?
Post by: mthee on March 27, 2022, 12:03:33 PM
Came across this as well which looks rough but cheap.  https://www.gumtree.com/p/honda-motorbikes/honda-cb250-rs-/1426750944 (https://www.gumtree.com/p/honda-motorbikes/honda-cb250-rs-/1426750944)    No compression? Could be all sorts. I am looking for a project rather than a running bike.

"Decompression lever needs repairing" wouldn't it be sweet, if it was just the lever stuck, holding the valve open?
Are you feeling lucky?
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on March 27, 2022, 01:08:13 PM

Are you feeling lucky?
PUNK.... we’ll, do ya feel lucky punk😁👍
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 27, 2022, 03:03:29 PM
Sounds to me like you need a Conda 250 !

Not to me I'm afraid.....

I've tried texting the compressionless one but no reply yet. There's a quite tidy bike on facebook marketplace - which I have never used - for £950 which rather puts the bobber in its place although I'm really looking for something to play with. The bobber has finished with no bids, surprise surprise. I'll see if he gets back to me.

Faceache ad: https://www.facebook.com/marketplace/item/352080140181546 (https://www.facebook.com/marketplace/item/352080140181546)

No-one here have one they want to dispose of (except spooky)?
Title: Re: Honda CB250RSA tips?
Post by: xbally on March 27, 2022, 04:29:08 PM
That looks quite tidy for the price.

Will need grab rails or a carrier.

Kms? Is it an import or has he fitted some other clocks?

Mileage may be verifiable by the documents or old MOT's?
Title: Re: Honda CB250RSA tips?
Post by: spooky on March 27, 2022, 05:50:49 PM
It does look ok, I can`t manage to sit on one as footrests are too high for my hips,  try before you buy ! I  have had the same  problem with every honda I have had since 2011, mostly twins (cb450dx/cb350s-g, nighthawk) but all either had to have footrests lowered or repositioned and none of them were comfortable.
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 28, 2022, 08:55:25 AM
I had the same problem with a grey import 400 four I owned for a year or so. I lowered the footrests (and lengthened the gear lever as my feet were too big!). I will need to do something to make it mone whatever.

Another project on ebay starting at £475 but it looks very rough. Tidy from a distance but probably not what I want. https://www.ebay.co.uk/itm/185360412478 (https://www.ebay.co.uk/itm/185360412478)
Title: Re: Honda CB250RSA tips?
Post by: xbally on March 28, 2022, 07:36:39 PM
Well Ian, if you wanted a project -that could keep you occupied for years. Looks to have spent some time outside or in an extremely damp environment. Not worth much more than the start price IMHO.
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 29, 2022, 09:09:24 AM
I'm going to have a look at the facebook one on Friday. Wish me luck. It does come with a pile of old MoTs etc although oddly when I put the reg number displayed into the DVLA MoT checker it says not yet tested. I will need to have a careful look.

TBH if it's decent and checks out I might offer near the asking price.

In other news delivered the xmax to its new owner yesterday morning and he seemed very pleased with it so that's good.
Title: Re: Honda CB250RSA tips?
Post by: mthee on March 29, 2022, 10:43:49 AM
Best of the bunch, IMO 👍 Fingers crossed for you for Friday!
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on March 29, 2022, 12:35:51 PM
Yeah... best of luck with the viewing Ian 🤞🤞
An old mate of mine got back in touch with me the other day after many o year. He was waxing lyrical about our times on our RS250’s... great memories, great bikes. Don’t think you’ll be disappointed if/when you get one 👍
Cheers, Michael
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 30, 2022, 02:51:57 PM
Having done some more research and considering what Martin said I see that the rear wheel and its cush drive setup is a weak point. To the extent that some people have said the cush drive locating recesses can greak up.

I was wondering whether a wheel from something else - say a GS250 - might fit if necessary after making suitable spacers etc to get everything lined up? Obviously would need a lot of thought but basically small capacity rear wheels from bikes of this era are much of a muchness.

I may well be overthinking this of course and will find that it is OK after all. And the little Honda won't be getting excessive use......
Title: Re: Honda CB250RSA tips?
Post by: xbally on March 30, 2022, 06:33:07 PM
Having done some more research and considering what Martin said I see that the rear wheel and its cush drive setup is a weak point. To the extent that some people have said the cush drive locating recesses can greak up.

I was wondering whether a wheel from something else - say a GS250 - might fit if necessary after making suitable spacers etc to get everything lined up? Obviously would need a lot of thought but basically small capacity rear wheels from bikes of this era are much of a muchness.

I may well be overthinking this of course and will find that it is OK after all. And the little Honda won't be getting excessive use......
Yes Ian, I'm pretty sure the RSD (De Luxe-electric start)  model rear wheel (as opposed to the RSA which has the cheapo cush drive ass'y) will bolt straight on.
There are quite a few RSA rear wheels about on Fleabay - well there used to be - and I've not heard of the locating recesses breaking up . As I think I said my first RSA  had high miles (I think it had been desptatched in London)and I never had a problem with the rear wheel itself-just the cush drive IIRC .And as Imay have said the difficulty is getting the bushes out.
Title: Re: Honda CB250RSA tips?
Post by: iansoady on March 31, 2022, 09:11:09 AM
Thanks Martin. Off to see the faceache one tomorrow.....
Title: Re: Honda CB250RSA tips?
Post by: xbally on March 31, 2022, 12:34:46 PM
Good luck Ian-I hope you can source a suitable bike at a good price.
A few years ago (like most bikes of this era)there were plenty around but values seem to increase exponentially -especially at 40 years when classic vehicle status is reached.
I'm planning a trip out to Droitwich PO tomorrow in the hope of getting my RS and KZ440 registered tax free-they are both already MOT exempt. (wife wants to have a look round the town.)
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 01, 2022, 09:22:35 AM
He's just sold the red one  :( but he has another blue one in even better condition having been restored by an ex-Honda mechanic - with a huge pile of receipts etc. Having spoken to the seller on the phone he seems like a decent chap so am off to see it on Sunday.

I was really looking for a project but ratty ones seem to be going for £700+ on ebay so £925 doesn't seem bad for this one - the days of £35 bikes have long gone. We'll see. He's fitting headlamp etc at the moment.

(http://www.iansoady.org.uk/CB250RSA/images/blue.jpg)
Title: Re: Honda CB250RSA tips?
Post by: xbally on April 01, 2022, 09:29:32 AM
Good luck with that one then-sounds like a fair price. Is it far away? I'm sure there will be jobs you can do on it! Off to PO now to try to sort out classic vehicle status for my RS and KZ.
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on April 01, 2022, 10:29:45 AM
Certainly looks mostly all there Ian and as Martin has said, seems like a fair price given what some folk are asking and again like Martin says, I’m sure there will be jobs to do on it... they’re “never finished” as the saying goes. Best of luck with it, obviously keep us posted 🤞👍
Cheers, Michael
Title: Re: Honda CB250RSA tips?
Post by: mthee on April 01, 2022, 10:56:07 AM
Could be a great big dollop of good luck, by the looks and sounds of it! 🤞🤞🤞
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 01, 2022, 11:16:23 AM
Thanks all. The seller also has a featherbed framed Norton single so must be a good chap!
Title: Re: Honda CB250RSA tips?
Post by: xbally on April 01, 2022, 04:41:39 PM
Got my RS changed to historic vehicle status today :) Another reason to get one!
Not sure what's going on with the fuel pipe in the pic? Presumably it's just tucked out of harms way as the bike is put back together.
Title: Re: Honda CB250RSA tips?
Post by: xbally on April 01, 2022, 08:34:47 PM
Here are a couple of others for you Ian :

https://www.ebay.co.uk/itm/294892108310?hash=item44a8f07a16:g:HMAAAOSwfqpiQ0S8

https://www.ebay.co.uk/itm/234486106532?hash=item36987609a4:g:my0AAOSwzxpiQvwC
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 02, 2022, 09:10:55 AM
Many thanks Martin, have been watching the second although not as good as the one I'm going to see tomorrow. The other may have a bit too much  to do......
Title: Re: Honda CB250RSA tips?
Post by: xbally on April 02, 2022, 09:20:31 AM
Many thanks Martin, have been watching the second although not as good as the one I'm going to see tomorrow. The other may have a bit too much  to do......
Well-you did say you wanted a project Ian!
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 02, 2022, 01:14:02 PM
There are projects and there are heartbreakers.........
Title: Re: Honda CB250RSA tips?
Post by: CrazyFrog on April 02, 2022, 05:36:33 PM
That looks promising!
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 03, 2022, 03:39:37 PM
Well, the little blue Honda is now in the garage - the seller delivered it to me for the same cost as shiply etc would have been after I went down to see it this morning. As always, looked better in the photos than the flesh but seems very sound. Immediate jobs - get a prop stand (several on ebay), sort out wiring which has been mangled, does sound tappety so need to look there. I don't think it's more serious. The bike came with a whole sheaf of receipts from David Silver and a well thumbed haynes book of lies so need to have a good look through these.
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on April 03, 2022, 04:21:31 PM
Great result Ian, congrats on your new purchase 👍. Keep us posted on any developments once you start to tinker with it.
Cheers, Michael
Title: Re: Honda CB250RSA tips?
Post by: mthee on April 03, 2022, 04:47:41 PM
Chuffed for you, Ian, but is the tinkering quota sufficient for your needs 🤔
Title: Re: Honda CB250RSA tips?
Post by: xbally on April 03, 2022, 05:39:35 PM
Excellent news Ian. Was it far away? Now the fun and games can begin. Centre stands can rot out so be aware. I had to get my mate to weld mine up but it now raises the rear wheel to a nice height. Never had any trouble with a side stand. Pictures please and yes they do all sound tappety. I hope you'll enjoy it.
Title: Re: Honda CB250RSA tips?
Post by: CrazyFrog on April 03, 2022, 06:26:30 PM
Great news Ian, a new bike day is always a good day!
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 04, 2022, 09:00:47 AM
Just about to check out the tappets / decompressor. All new stuff to me so another school day.
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 04, 2022, 03:38:34 PM
Sorted out the rattle.It looks as though the roll pin locating the decompressor is missing so the decompressor spindle can slide in & out. One of the exhaust clearances was also on the wide side. Those little 3mm adjusters re a real pain - I used to have a King Dick adjustable that was just the job but it's hidden itself somewhere. It's not too bad to start without the decompressor although I'd prefer it to work.

Lots of minor work to do - rats' nest wiring, sloppy gearchange linkage, I've got a propstand on ebay (this one was missing), etc etc. The micron exhaust is a bit loud but I can live with that - it's louder than the Norton.

Incidentally had my insurance renewal from Peter James and they want £109 for the 2 bikes - agreed value on the Norton. I got a quote from RH - all the same details - and it's £88 so I will be moving after several years. RH use Equity Red Star but PJ have moved to someone else I've never heard of. Unusually PJ wouldn't move at all so lost a customer - I might have stayed if they'd split the difference.
Title: Re: Honda CB250RSA tips?
Post by: Itsme on April 04, 2022, 05:16:11 PM
Hi Ian

Just seen this great news. You have to have it ready for when we set a date for thumperteers to meet up at the National Motorcycle Museum. It looks lovely and I hope you will have loads of fun tinkering.

Spartacian
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 05, 2022, 09:23:09 AM
No..... I'll be on the Norton!
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 05, 2022, 01:09:11 PM
Cracking on......

Popped the back wheel off as there was a lot of travel on the brake. The Haynes book of lies suggests a minimum lining thickness of 4mm; the official Honda one 2mm. There's 3mm and a lot of clearance so I've ordered a pair of shoes from ebay - at £9.99 posted not a big deal. In passing, both tyres are unworn TT100s which I haven't used since I had them on The Commando in the 90s and 00s - so nice tyres. Both are relatively recent as well. Without dismantling, the cush drive looks decent so will leave well alone.

The gear linkage was very sloppy so I've removed the ball joints - easy by grinding off the riveted over section on the back of the lever & operating arm - and ordered new rose joints again from ebay at around £5.

Everything is coming apart nicely. I hope it goes back together as well. I did notice what looked like silicone on the rocker cover / head joint so will order a gasket set as I need to fix the errant decompressor. I was wondering whether to fit a handlebar lever for that rather than rely on the kickstart operated arrangement which as I'm a dyed in the wool traditionalist I find a bit wimpish......
Title: Re: Honda CB250RSA tips?
Post by: Itsme on April 05, 2022, 02:47:13 PM
No..... I'll be on the Norton!

Oh yes forgot about that. Good choice!

Spartacian
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 09, 2022, 11:59:29 AM
Cracking further on.....

I took the cam cover off to find out why the decompressor was flapping about and discovered there was no dowel holding it! Not surprising it rattled. New pin and oil seal ordered - the latter arrived from Simply Bearings the next day, still waiting for the pin. I found the tappet adjustment to be really tricky with that tiny 3mm square so I made a tool. Got a 4mm spoke and filed a tapered square on the end. A bit of 12mm soft alloy rod in the lathe and bored a 3mm hole in the end then tapped that onto the spoke to form a square hole. Finally tidied up with knurling etc....

(http://www.iansoady.org.uk/CB250RSA/images/tappet%20tool.jpg)

They are apparently available but why spend £10?

Also got some rose joints from ebay and fitted to the gear linkage which was very sloppy:

(http://www.iansoady.org.uk/CB250RSA/images/linkage.jpg)

I haven't bothered with the boots being a fair weather softie.

Painted and fitted the prop stand from ebay, played about with different handlebars - the bike came with Vincent straights so have used some risers I had lying about to lift them a bit. Oiled the clutch cable but it's still a bit sticky. Waiting for replacement brake shoes and gasket set - although I suspect there's nowt in there I need as the rocker cover doesn't have one and I think O rings aren't included.

Pleased with progress so far, and think I have got a good deal with the bike. There seems to be very little wear on camshaft / followers, the timing chain tensioner is looking very good and should all be ready to put on the road before long.

I have insured it with RH after being with Peter James for years as RH offered me £88 for the 2 bikes whereas PJ wanted £110. Shame but as often said loyalty doesn't pay these days.
Title: Re: Honda CB250RSA tips?
Post by: mthee on April 09, 2022, 11:33:08 PM
Love the homemade tool and glad to hear she's in good nick 👍
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on April 18, 2022, 03:21:52 PM
Just returned from a week away on holiday, so just catching up on posts. Glad to hear you’re making decent progress with the RS Ian. Perfect timing for hopefully the decent weather kicking in 👍
Cheers, Michael
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 19, 2022, 11:31:48 AM
Yes, coming along well. Fortunately there were no stripped threads in the head / rocker cover and the camshaft bearing surfaces, cams and followers were all fine. The rattle turned out to be the totally missing dowel pin that locates the decompressor allowing it to float about - I managed to get one and once fitted, and a new oil seal all went together niicely. It starts well but spits a bit on opening the throttle. I've got the carb off and the accelerator pump diaphragm is all curly. Although I don't subscribe to the view that ethanol will stop all life as we know it, it's quite possible that it has affected this part. I've found a place called NRP carbs that seems to have the diaphragms so will give them a try.

I've also sorted out the wiring which was a real mess with horrible crimped on connectors, fuses jammed into bent bits of tin etc. Fitted the new rear brake shoes which was very straightforward. I've ordered a round headlamp from ebay as I think the one thing that spoils the look is that weird rectangular one. Lubricated throttle and clutch cables so they now move....

It should be on the road in a couple of weeks or so but no rush. As often the case, previous owners have done some things very well and bodged others but it's nowhere near the disaster it might have been and hasn't cost a lot so far.

Speaking of camshaft bearings, I caught an episode of the Speedshop on BBC. I'm not too keen on the central character but he does know his stuff. As it happens he was rebuilding a 1974 CB350 which has a similar head layout and the bearings were shot. He fixed it by doing something I'd though might be necessary - boring out the head / rocker cover to take needle rollers. That seemed to come out well as he managed most of the Weston beach race with it.
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on April 19, 2022, 02:36:48 PM
I've ordered a round headlamp from ebay as I think the one thing that spoils the look is that weird rectangular one.
Yes I remember when I bought mine new back in 1981 I hated the rectangular headlight too Ian. I bought the genuine Honda cockpit fairing available at the time which I thought very stylish back then.
I now think it’s the rectangular headlight that kind of defines the RS. However I’m sure it will look equally as stylish with a standard round headlight in place. I look forward to seeing a couple of pics once you’ve done the conversion 👍
Cheers Michael
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 25, 2022, 03:44:05 PM
All just about done now. The round headlight looks much better although possibly I should have gone for a 5.5" one as the 7" one looks on the big side and of course there's miles of surplus wiring behind it. When I stripped the carb I found the accelerator pump daiphragm was all crinkly which I think explained why it was spitting back on opening the throttle. I suspect this may be my first adverse ethanol experience! The diaphragm flattens out when dried off and left to rest and I've refitted it in that state so hopefully the clamping effect between the seat and cap will keep it in order. Initial start up was running much better and I'm quite impressed by the automatic decompressor although have to remember to let the kickstart come completely to the top.

A bit busy over the next week or so but possibly first ride before long. Hoping I can get on it as although the replacement hip joint is working perfectly I need to get all the muscles loosened up a bit.

(http://www.iansoady.org.uk/CB250RSA/images/front%20left.jpg)

(http://www.iansoady.org.uk/CB250RSA/images/front%20right.jpg)
Title: Re: Honda CB250RSA tips?
Post by: CrazyFrog on April 25, 2022, 05:06:00 PM
It's amazing how the round headlamp transforms the bike - it looks really good!
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on April 25, 2022, 05:45:58 PM
Yes, looks very nice Ian. The whole bike I mean not just the headlight, looks like you’ve got yourself a cracking little RS250. Hopefully you have many miles of great riding on it👍
Cheers, Michael
Title: Re: Honda CB250RSA tips?
Post by: mthee on April 25, 2022, 08:39:18 PM
Well fettled that man!👏
Title: Re: Honda CB250RSA tips?
Post by: themoudie on April 26, 2022, 09:01:37 AM
Aye Ian, that is a very neat wee beastie you have there now. Hope the muscles get tuned up and you can enjoy putting the miles under the wheels.

Good health, Bill
Title: Re: Honda CB250RSA tips?
Post by: iansoady on April 26, 2022, 09:21:01 AM
Yes, am very pleased so far with progress. I think I may look for a smaller bore brake master scylinder as the front brake is very wooden feeling. I did the same to my Guzzi V50 and that improved it no end. It's only cost me £100 or so in bits so far including the aftermarket mirrors which were a snip at £6.99 from ebay, and the headlamp at under £20 from the same source. It does help to have a comprehensive scrap pile......
Title: Re: Honda CB250RSA tips?
Post by: themoudie on April 26, 2022, 03:18:40 PM
Quote
It does help to have a comprehensive scrap pile......

Useful paraphenalia!  ;)

Bill
Title: Re: Honda CB250RSA tips?
Post by: xbally on April 26, 2022, 03:41:42 PM
Yes agree about the round headlight.
As to the front brake-yes it's standard 80's fayre and pretty wooden with little or no danger of a lock up.
I'll be interested to hear if you can improve it with your planned mods.
Title: Re: Honda CB250RSA tips?
Post by: Itsme on April 26, 2022, 04:47:33 PM
Hi Ian

That is looking lovely, a very useful, tidy thumper and the work you have done is very tasteful. Hopefully we will get a decent summer so you can get out there and have fun.

As for the hip, the daughter of a friend of mine is a physio for the, ahem, more mature person and her favourite saying is 'motion is lotion' so keep it moving and all should be well.

Spartacian
Title: Re: Honda CB250RSA tips?
Post by: tevie54 on May 12, 2022, 09:42:09 AM
That's a very nice looking bike you've got there, you've done all the usual RS bits that need doing, personally I prefer the rectangular headlight as that defines the bike from all the other early eighties bikes but that's just a personal thing.
Other mods you can do are CBX250 wheels, they have a better cush drive, Hagon shocks work well.
Sometimes the oil leak from the head is actually from the O ring on the ends of the rocker shafts, bit of a pig to fix but unavoidable I'm afraid.
They sometimes crack between the spark plug hole and a valve seat but I've known these go go for years before you need to do anything, the generators are a weak spot and lead to intermittent starting, I think WEMOTO list new generators for the RS.
All in all a cracking little bike, I've had five and converted the last one to 500.
Title: Re: Honda CB250RSA tips?
Post by: xbally on May 12, 2022, 03:48:40 PM
Interesting.......My current one which I've had for about 8ish years I think has always leaked very slightly from the head-very unHonda like behaviour. My mate tried to fix it with some special sealant but it continues to leak ever so slightly and very annoying.I think he replaced the O rings you mention at the same time. Didn't know about the generator.
I've always thought these would be a much more interesting ride with a 500 engine. Have you still got your CB500RS? Any pics? Which engine did you use? FT /XBR/ XL ? Kick start only? Is it easy to start?
Title: Re: Honda CB250RSA tips?
Post by: tevie54 on May 12, 2022, 06:52:27 PM
Yes I don't think I had an RS that didn't need a new generator at some point, the ignition winding coil works loose causing earthing problems within the generator itself. Electrex World list one for the electric start model but are out of stock of the kick start model at the moment. Westcountry Windings will rewind yours for you but they are quite expensive, I had about five generators at one time that I offered to Westcountry Windings for free in return for one rewound one back but they said they'll only do one at a time for the customer and don't keep any in stock.
 I've still got my 500, I'll try and upload some photos, mine uses the XL500 motor with kick start and it starts easy.
Title: Re: Honda CB250RSA tips?
Post by: xbally on May 12, 2022, 07:12:25 PM
Brilliant shot-I thought it would be a wheelie merchant! Mine leads a mainly pampered life as I have other bikes so am lucky to cover 1000 miles in a year but I do use it for a spot of commuting and chilling out round the local lanes. So far it's been extremely reliable but I'll watch out for starting issues-thanks for the heads up. I think your RS500 would make a good hillclimber?
Title: Re: Honda CB250RSA tips?
Post by: themoudie on May 12, 2022, 08:20:03 PM
Aye tevi54, thank you for posting the image, lovely shot of what a motorbike should be about; lightweight, poky, but not sucidal and easy on the eye.

Good health, Bill
Title: Re: Honda CB250RSA tips?
Post by: mthee on May 12, 2022, 11:48:34 PM
Catches a few people out, does she? Lovely, thanks for sharing and any more pics, please?
Title: Re: Honda CB250RSA tips?
Post by: tevie54 on May 13, 2022, 07:01:33 AM
I've got more somewhere but it's getting them uploaded that's the challenge
Title: Re: Honda CB250RSA tips?
Post by: iansoady on May 13, 2022, 08:55:52 AM
Looks good with the 500 motor but they now seem very rare. I read somewhere that the top engine mounting was a challenge with the bigger engine?
Title: Re: Honda CB250RSA tips?
Post by: mthee on May 13, 2022, 10:49:58 AM
What a beautiful bike! Any chance you could list the work done/describe the build?
Title: Re: Honda CB250RSA tips?
Post by: tevie54 on May 13, 2022, 11:14:26 AM
Yes the top engine mount does need some modification, some people just cut it off but I reduced it's size so I could still bolt it to the frame.
I've done some Youtube videos of the build, type in Honda CB500RS or Honda CB250/500.
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on May 13, 2022, 03:48:08 PM
Yes cracking looking bike tevie54. The black rims set it off nicely. As Bill says, it conjures up what a bike should be, light, nimble, quick... and last but not least FUN.
Cheers ...Michael
Title: Re: Honda CB250RSA tips?
Post by: xbally on May 13, 2022, 04:45:53 PM
I've just watched a couple of the vids-very impressive.Have you still got the bike?
Title: Re: Honda CB250RSA tips?
Post by: tevie54 on May 13, 2022, 05:31:18 PM
Yes I've still got the bike although its doing this funny jumping out of first and straight back in, I'll have to have another look at the gearbox again.
Title: Re: Honda CB250RSA tips?
Post by: mthee on May 13, 2022, 08:00:23 PM
Thanks for the video heads-up. In the comments, someone has tried to get you to part with it and in your reply, declining his offer, you say it isn't exactly relaxing to ride. Did your very impressive, lengthened swingarm help sort this?
Title: Re: Honda CB250RSA tips?
Post by: tevie54 on May 13, 2022, 09:04:58 PM
The lengthened swinging arm helped considerably, the bike was less twitchy over bumps and the wheelies over the mountain at Cadwell were far more controllable, when I say it's not relaxing to ride I mean It's no longer the softly sprung gently powered moderately braked commuter bike that was the RS250. Now It's a firmly sprung, torquey (32 ftlbs) 40 bhp fun bike with tremendous brakes but still weighing only 125kg, so rather than go out for a gentle Sunday afternoon cruise you find yourself behaving like a hooligan and trying to pull wheelies everywhere and reveling in the torque wave, the other day I found myself pulling 90 and still accelerating (on a private road obviously) I've considered selling it a few times but every time I open the garage door and look at it I just cant bring myself to part with it.
Title: Re: Honda CB250RSA tips?
Post by: xbally on May 13, 2022, 09:43:24 PM
Sounds as though you should also get another standard RS to provide more chance of keeping your licence safe-and stick to the track for the majority of the rides on it.......Might be a bit dull though after the RS500.........
Title: Re: Honda CB250RSA tips?
Post by: mthee on May 13, 2022, 10:43:25 PM
Glad to hear you've tamed the beast sufficiently to enjoy that power to weight ratio. I hope no one ever manages to buy her off you 👍😎
Title: Re: Honda CB250RSA tips?
Post by: Moto63 on May 14, 2022, 08:43:11 AM
enjoy that power to weight ratio. I hope no one ever manages to buy her off you 👍😎
Yes I totally agree with Matt, looks like waaay to much fun to part with, especially given the amount of work you’ve clearly put into it. 👍
Cheers, Michael