this bike deserves to be burned

[dizzyblonde]

okay, on the advise of Sid Squid at the AR, we decided to un-cease the choke cables,as it were running that rich it wouldn't run right.
Did that and boy were they stuck solid, screws that tight an hour and a half later and lots of freeze and release spray, they were fixed. Not a blind bit of difference.
Next tried to give it some new spark plugs, appeared to be better til 2 days later
Balance the carbs we thought, filthy, so we'll clean them too, all jets and everything so clean you can eat your dinner out of them.
They won't balance, in fact they're so opposite end of the scale its very peculiar. My bloke has done this many times and isn't a muppet....

So now its over to you guys,this mystery needs solving...we're next going down the shims and valve clearances as the previous owner reckons on to have done it, double checking them.
After inpecting the colour of the spark plugs it was clear that the back pot was running alot richer than the front. The read out from the balancing clocks told the story. the front pot seemed to give quite a normal reading but the back pot sucked big time and that's just about summed my day up. IT
SUCKED!!!!!!!!!!!!!!!!!

[northwind]

Vacuum leak? Damaged inlet rubber?

[dizzyblonde]

Hi dude it's Me indoors, can't really say if it were a vacuum leak the only thing i didn't do by the haynes manual is change the O-rings on the inside of the inlet rubbers and choke plungers. think it may be more likely to be valve clearences that need checking rather than an air leak.
sick of it.

[northwind]

Worth checking, but that wouldn't usually cause richness, just all sorts of other bad stuff. Did you attach the vacuum gauges directly to the nipple on the carbs, or to some hosery?

I'd have a look down the carbs and see if the slides seem to be operating equally... But if it misfires, it may spray petrol in your eyes, so be careful

Actually, no I wouldn't, I'd swap the carbs off the other bike and see what happens.

[dizzyblonde]

straight on the nips, carb sliders working equally, diaphragms undamaged
the front pot reads 3 o clock, back pot 12 o clock, a bit odd don't you think

[northwind]

Yup, definately. That's why I reckon a leak. But I'd have thought that should be obvious from the slide action. Hum. It does vaguely remind me of what happens if the needle jumps out of its seat, but again that should be visible.

[dizzyblonde]

they weren't loose, although one got stuck when we first refitted the carb and leaked petrol everywhere ( in fact filled carb up after painstakingly cleaningof crud)-one float got stuck, made sure it wasn't repeated thats for sure!!

[rictus01]

Just as a matter of interest the jets are the same size aren't they ?
both choke plungers returning correctly ? if one sticks then it could account for it.

But andy's right the easiest way is to try the other carbs and see if the problem goes away or if you put the carbs on the other one, that will tell you if it's the cables, intake rubbers or carbs.

Cheers Mark.

I think it is the rear choke cable/mechanism not closing off properly ... have you looked at the little rubber sealing bit on the plunger at the bottom of the cable? is it damaged? is there muck on it?!?!

[dizzyblonde]

we gave the choke cables a jolly good clean, all checked and nowt appears to be wrong...we'd do the carb transplant but the yellow ones at his house an unfortunately there's two broken bikes to fix here, today its the turn of the raptor, cause that won't work at all...and I am staying well clear of that one....I might get a hammer thrown at me!!!