[Aduro]

Pretty sure my bike is running lean, running way to hot no matter how cold it is and just doesnt feel like shes pulling as she should.

Changed the carby boots a week ago as it was causing it to run on 3 cylinders, put in a new air filter and changed the oil/oil filter, the smart thign to do would be to put the old filter back in for the mean time but i tossed it.

I realise pulling quick fixes leads to bigger problems down the track, but i dont have the time or money to fuck with it atm as it seems to be one thing after another with this F'ckn bike.
That said i dont want to damage it further by riding around lean (its my only transport)
Would a simple balance of the carbys fix this or does it need to hit a dyno and be properly tuned?
In the meantime how well would i go fixing up some sort of mild air restriction to put under the air filter? (possible just some more foam or a sheet of paper with holes through it)

 

[Matt]

if you know anything about carbies its pretty easy to fiddle with the ratio. i don't know how much use it would be though as you wont be able to measure the ratios at the other end. best bet is to figure out how many turns out your mixture screws are and give it another quarter turn for now.

 

[Guest]

I was under the impression the mixture screws only affect the idle, and not the mid-top end.... *shrug*

 

[Matt]

the small jets affect idle ratios, then theres enough pressure after a few thousand rpm to suck through the big jets. the mixture screws change the fuel-air ratio no matter what.

 

[banana.logic]

yes that is what I thought too roobars.

Aduro, can you explain to us what happens when your bike is sitting at idle when it is warm, and you rev up to about 4K rpm and close the throttle.

also it could be a cooling system issue, how hot does it run and how quickly does it get to this temp?

have you pulled the plugs and inspected them to get a rough ideal of how it's running? check this out http://www.zionmoto.com.au/sparkplugs.html

When did you last do a carb clean?

 

[Aduro]

Cleaned the carbs less than 3 weeks ago when i had the problem with the dropped cylinder.
I was fairly certain its running lean, as it was perfect right after i put the new boots on but then started playing up after i replaced the horribly dirty air filter. ( Ill add here that it was last serviced and tuned or whatever by a mechanic with that dirty filter on it)
Although im no expert, this site is like a CBR bible.
I havent got around to checking out the plugs mainly cuz im short on time atm and to be honest bit over something fucking out on the bike every month.

Sitting at idle the engine doesn't seem to run smoothly, it hunts a little bit (150-200 rpm) but sounds like its thrumming more than one constant cycle.
If i rev and let it drop to idle it does hang, but its not significant.
Also noticed that if i give it a bit of throttle or some higher revs then pull up sharply (orange - red light) it has an odd smell.

Its possible there's something up with the coolant, i changed that not long ago and used concentrate, but fairly sure the ratios are fine. i bled the air from the coolant system last week didnt really seem to help.

best bet mixture screws out 1/4 turn then?