CB250RSA Very sluggish, how can i fix it quickly?

[2E]

Right, basically i just bought a new commuter hack which is a 1981 Honda CB250RSA

Its a kickstart-only model and seems to be in good nick. I bought it over ebay and the seller half-rode it down (rode to dartford and his mate put it in a van with something else he had bought to take it the rest of the way).
I need to fit it with a few trivial things like mirrors and indicators as it doesn't have either!

Unfortunately i had to leave money with someone else who bought and signed for the bike on my behalf, therefore tonights the first time i've seen and rode the bike.

He claims it was riding really well, the tyre pressures were not up to much so i pumped both tyres up, then took it out for a spin.
It was struggling to rev past 5000rpm, felt extremely restricted/bogged down, almost as if it was struggling for fuel which i presumed it was, it confirmed this by stalling across the road from the petrol station.

I filled her up fully and after a few kicks she fired up again, she was a bit more responsive off the bat but between 4000-5000rpm it would bog down, i could 'rev' out of it but it would still feel very juddery, changing gear helped a little but only until it hit the same spot and the symptons would continue.

My personal guess is that its sucked crap into the tubes/carbs as i run it to empty, I need this bike for Friday/Monday as im working overtime (early shift!) and the trains are ridiculous on these days (sunday service/bank holiday)

Will REDEX do the job sufficiently enough for 3 days worth of commuting, i then have a week off so i can strip down the carbs and clean them properly.

My main concern is hitting a main motorway type road e.g. north circ and it bogging down.
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Bringing Classic Bikes Back Into Fashion
Rides: 1980 Honda CX500

[N cee thirty]

tbh i'd get the carbs off now and clean them out

wouldn't fancy going anywhere espc the motorway with it not running right

i heard you have to change the oil quite regular on these aswell

clean the air filter and change the plugs
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[2E]

I need it for friday and am at work 8-6 everyday... hardly get anytime other than the weekend, plus time for stuff to arrive in the post.
____________________
Bringing Classic Bikes Back Into Fashion
Rides: 1980 Honda CX500

[Robby]

Once again, I will ignore all of your sob stories and excuses, but I know a thing or two about that particular bike. I'll have 3 of them after I make my pickup on Friday.

Not revving and then cutting out on idle is almost certainly down to the carb, main culprits being dirt in the mixture needle hole and water in the accelerator pump chamber. Take the carb off and clean it, being sure to remove the mixture screw and blow carb cleaner into the hole using the straw attachment, and also be sure to remove the accelerator pump chamber cover on the bottom of the float bowl and blow through the small holes between this and the float bowl proper.

I don't recommend taking the top of the carb apart, the trouble happens in the small holes low down. Don't lose the tiny O ring on the accelerator pump jet between the float bowl and carb body.


Other useful things to know for the bike:
1. Fit an inline fuel filter (paper type) immediately. The tanks rust and the carbs don't like rust.
2. Never run it out of fuel. Try to avoid reserve in general. You've found out why the hard way.
3. Change the oil every 1000 miles or less, using cheap 10W40. They don't have oil filters, just a crap little mesh gauze. The little jet that shoots oil up to the head is a finer bore than the mesh gauze. Blocked jet = no oil to the head. You can tell when the instant gasket sealing the rocker cover to the head starts bubbling.
4. In a pinch, they can start and run without a battery.
5. The standard headlight is fine, don't fit an aftermarket one. Any headlights problems can be down to the aformentioned lack of/knackered battery.
6. They can be quite heavy on chains. David Silver's do a chain for £16.50, which lasts about as long as an O ring on one of these.
7. You can get a pair of Michelin tyres to fit delivered to your door for under £75.
8. Carry a spare plug, they occasionally get eaten.
9. Your left shin will get a bit oily, they all weep a bit of oil from the rocker cover.
10. Clean the corrosion out from behind the piston seal on the brake caliper to get brakes that work.

[Ed Case]

Just to be awkward, I got fed up with the shite 'square' headlight and fitted a replica RD250/350 one with a 60/55 halogen bulb in from M & P (£24-ish). What a difference, knocks spots off the 'Yellow Custard' like output of the original. The charging system CAN handle it as I run with dipped-beam all the time. Bollox to originality I want to see and be seen, there's too many 'Asleep at the Wheel' pratts these days.