Honda CB250RSA tips?

[mthee]

Chuffed for you, Ian, but is the tinkering quota sufficient for your needs 🤔

[xbally]

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.

[CrazyFrog]

Great news Ian, a new bike day is always a good day!

[iansoady]

Just about to check out the tappets / decompressor. All new stuff to me so another school day.

[iansoady]

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.

[Itsme]

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

[iansoady]

No..... I'll be on the Norton!

[iansoady]

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......

[Itsme]

No..... I'll be on the Norton!

Oh yes forgot about that. Good choice!

Spartacian

[iansoady]

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....



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:



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.

[mthee]

Love the homemade tool and glad to hear she's in good nick 👍

[Moto63]

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

[iansoady]

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.

[Moto63]

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

[iansoady]

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.