running on one

[redtrummy]

Thank you R1ff - reckon I have a lot to check!

[garynortheast]

Any progress on this RT?

[redtrummy]

Thanks for asking Gary - Too cold for me in the garage! New plugs and JIS screwdriver arrived (Bibs choice) Midway in renewing the lads bathroom as well - Granddaughter arrival expected anytime soon. Been on at him for 3years to get it done now its panic stations! so I may end up Sorning it at the end of the month until I have more free time. The Cub is/was running well but roads wet/salt no way.

I wonder what it is but I really miss not being out on two wheels, suffering withdrawal symptoms I think!

[redtrummy]

On the black side of life! The lads bathroom is not yet finished! (Only limited access now, cannot disturb the newborn. However, in the meantime I mulled Suzy's problems over, surely if it was electrical then fuel would be dumped into the exhaust which would cause popping and banging which just didn't happen? So I started the bike to recheck and promptly burnt my hand touching the front exhaust pipe, ran it through the rev band and above 6k it was obviously running fine. (I doubt in my local area I have reason to hit 5 -6 k when riding her, so back to carburation. The bike had very little fuel in it so gave it another good shot of Redex (Bow down to the powers of Redex) ran the bike for a few minutes, left it for a couple of weeks, tried it again with a short run and it was running pretty well with the odd misfire! Hopefully I will be taking it on a bit of a run tomorrow to check its current status. If the outcome is good I will own an unused JIS screwdriver and a couple of spare sparkplugs, time and test will tell! Or on the black side of life I have an intermittent problem

[Ruffy]

Fingers crossed! Hopefully it was a bit of dirt in the carb innards somewhere that's now been dislodged, dissolved or burnt away.

Pretty sure you'll find a use for that JIS screwdriver eventually - good tools are never a waste for practical hands, it's just a matter of timing! And the plugs will be ready for next routine service time.

[Biker Biggles]

Did you ever take the choke plungers out and make sure they are free and working? The front one is awkward to get at and they are very often the source of running issues on the carb model.

[redtrummy]

No but I figured out where they are and if problems continue I will thanks for the reminder! First it needs an oil change so does the Cub, both lawnmowers and the motorhome and the car , garage full of oil ready. Just need the weather to warm up first, plus got the garden to set, ground too cold here yet. Better than being bored I guess.

[redtrummy]

Progress! After a short run on Sunday Suzy started spluttering so Monday I decided I would have the front choke plunger out if I could get it out (thanks for the reminder again Biker Biggles) so full of trepidation I removed tank and air box when I heard something fall - it was a tank retaining washer, luckily it missed falling into a carb! Thought must be my lucky day things usually go wrong for me, so rags bunged into the carb mouths and onto the plunger. It WAS my lucky day the retaining plate screw was a good 8 mill out, loose! So carefully removed the screw, plate and plunger, every thing clean as a whistle! Bunged a little grease on the plunger and spring and carefully replaced the items back into position then took it for a spin. A lot better but still seemed to misfire now and again but I did the long overdue oil change. Ran it up for its MOT today and it seemed fine so hopefully the end of this saga! That plunger and associated bits has not been touched in 24 years of ownership.
Must say it was a lot easier job than what I was expecting. Thanks all

[redtrummy]

Decided to give the bikes engine a turnover in the hope of perhaps having a run on it now its finally stopped raining! Noticed a pool under the bike- on tracing its source it appears to be diluted petrol/oil and the petrol component is coming from the rear carb. Have read previous threads I think the petrol tap may be the favorite cause allowing fuel down the vacuum pipe . It seems to still run fuel after I have switched the bike off so I propose that is my starting point tomorrow,
then sticking float/needle?


Does anyone have any other suggestions what may be the culprit?



Thanks

[R1ffR4ff]

Yes. Failing or failed Petcock and float heights incorrect/stuck. Has happened to me on one of my old Hondas with CV carbs when the bike was left on the side-stand. The fuel also got past the inlet valves and contaminated the oil. You could smell the petrol in the oil from the filler hole and caused a vapour-lock/hard turn-over.

I drained the oil and replaced it with some cheap 20w50 and ran that for a few mins and then dumped it. I repeated this again and the put proper oil in with new filter . I did not want any bottom-end shell contamination that could ruin the engine.

You may be lucky and no fuel in the oil but if not see above.