Anemic running curvy. Probably carbs related

[Vindaloo]

I've a (lovely) curvy and have been having a few troubles with it starting and running for a few months now. Recently though it's taken a lot of effort to get it started - and when it does, there's more white smoke coming from the exhaust than I'd think usual.

It's had issues ticking over on idle whilst waiting at lights for a while but at times, it struggles ticking-over. Its always ridden fine but recently has problems under hard accelleration but only from low speed. I reckon it's at least in part carb related.

So: I reckon it's could be one, more, or none of the following:

o Last year I balanced the carbs. The variance in reading on one carb (max to min) was much larger to that on the other. Is this normal?

o I attached a <12in pipe to the front carb exhaust after balancing to make it easier to check in future. Is this too long and how else could I cap it?

o The air filter: It's old but there's only slight discolouration and I think it looks good, though I don't know what a bad one would look like. It's not covered in oil.

o The battery could be having trouble turning the bike over. It has a couple of breakout switches for heated grips and for a charger, but they're not drawing power. Don't think this could be an issue? It's a <12mo old Yuasa. This wouldn't affect the running problems.

o The engine could just be beggared. Its been replaced and the oil coming out of it was jet black for quite some time. I don't think it's a great, specimen regardless.

o Valve clearances worth checking?

The weather / temperature at the moment doesn't help, I know, but it's worse than it should be.

Anyone got any comments or other ideas?

[hardhat_harry]

I'd go for airfilter on this one if you aint changed it in a while.

[Biker Biggles]

Inlet air leak?Did the problem start after you stuck that bit of pipe on the carb,or after you lifted the airbox?

[yorkie_chris]

You need to plug that 12in bit of pipe with a bolt or something... it does not matter how long it is so long as it is sealed.

A bit of white smoke is generally just water vapour, nothing to worry about.
Oil coming out black is also normal.

Is tickover high enough? (sounds daft I know) Chokes could also be sticky.

[Biker Biggles]

If it is leaking air into the front inlet you should be able to confirm it by pulling the plugs out and seeing if the front one is running lean.In fact looking at the plugs is a good idea anyway as it will reveal lots about how it is running.

[Vindaloo]

Hi, thanks a lot!

I'll see how it starts and runs without an air filter in a minute. Would be a nice, easy fix, but not the best time of year to run without an air filter :-).

Inlet air leak is feasible. As far as I can tell though it's sat tight on the carbs. I have re-seated this many times and have inadvertantly ridden without it seated properly once or twice over the last 12 months. I'll have another check.

The pipe is plugged (well tied securely enough). I'm tempted to fit a valve to it though as when it's not connected you can have great fun shooting flames out of the exhaust! Good to know the length doesn't matter.

Tickover is high enough when the engine's really warm after maybe half an hour's riding, but low at first. The choke is sticky on the handlebar end to engage for sure.

If I've time today or tomorrow, I'll take a look at that front plug. Pretty sure whatever the cause it'll be sooty as it feels like it's just not running cleanly and efficiently. I've a couple of spares handy. I'm sure that'll help, regardless.

Seriously, guys, thanks for the help. I'll go get my fingers filthy again now.

Adrian

[husky03]

sounds like your carbs also will benefit from a decent service-get the choke plungers out and see what state there in, your bike shouldn't be taking half an hour to be running smooth.

[Vindaloo]

Right.

Have changed the oil (filthier than Frankie Boyle), swapped the front and rear sparks (sootier than a 1980's children's TV show) and reseated the air box. There did appear to be a slight air leak. I don't seem to be able to keep it set tight.

It's definitely running a lot better now (as you'd expect!). I still wouldn't say it's perfect, though. Starts up a lot better, idles ok-ish but the throttle response from idle is very poor. Maybe because it's idling too low (until it gets proper warm)? Don't know what I can do about the idle adjuster being seized other than buying a new set of carbs. I WD40-d the throttle cable end of it to death earlier this year and it made no difference.

I'll see what's involved in looking at the choke plungers when I figure out what they are.

It could do with a good service, but I aint taking it to a shop til I've done what I can myself. Looking through the service intervals, though I've pretty much done most of the required work <big smiley thing>.

Adrian

[Vindaloo]

As a side note - is there anything more annoying and fiddly than replacing that front spark plug?

thanks again,

Adrian

[Biker Biggles]

Choke plungers.Have a little search on here for what to do,but bear in mind you may need an impact driver to get them out.

[husky03]

get your carbs off the bike and you'll find them mucho easier to work on-as BB said re the plungers they can be a sod to get into due to the cheesey screwheads melting ,once you've done this you'll be able to get the idle adjuster loosened-try popping it out the holding bracket and turning it -might work.
It sounds like your gonna have to give things a good strip and clean then once back together you'll see if you've fixed the prob.

[Vindaloo]

Cheers. Sounds like an effort, but probably best done when the bike's in pieces as it is at the moment but will probably have to wait until next weekend at least now. I can't really ride it at the moment to see how it rides until I've sorted out the rear brakes, but it does sound and feel better for a little bit of love - just startign up and riding around the car park here.

thanks again,

Adrian

[sunshine]

I have had the same problem its been said, rebuild the carbs, if like me your doing it for the first time ever, expect the chock plungers to be seized up, the springs to be broken and a new choke cable because its old and the cable isnt moving freely. I also had to rebuild the fuel tap but thats a completely different problem. when refitting the carbs after rebuild and sorting the choke out you will also need to balance them.

Also a general service wouldnt go a miss, old oil is thick and black after 3K (monthly for me) which is when i do my services, i also change my filters, oil and air, every other service.

[Vindaloo]

Joy! The bike's 9 years old now and kept outside. After a couple of years of me working away, not riding it a huge amount and being sat all winter, most nuts, bolts and screws are seized. Sounds like a good day's worth of fun of munging crappy screw heads and lots of swearing. Get the impression it might be worth getting an impact driver before even starting.

I'll get a new air filter in there regardless next chance I get.

cheers,

Adrian