Carburation.. Best way to richen her up?

[Yoniboi]

Hello there everyone.

I'm running in my Wiseco 1040, standard airbox, slip on ally can, and all standard jets + almost new emulsion tubes + needle jets.
Floats set at 14mm with Dr.Jim's tool.
'Air' screw 2.25 turns out.
Carbs thoroughly cleaned, all passageways clear.
New NGK standard plugs.
Valves double checked and within spec.
0.5mm skimmed off head a couple of years ago by necessity not choice, but doesn't seem to have affected much.

Ambient air temp 13ºC mornings, 30ºC afternoon.
750m above sea level.

Bike starts with a little choke that needs removing after 10 seconds.
She runs a little rough which I'm putting down to not having balanced the carbs yet.
She runs a little better in the morning than in the afternoon, and a lot better when cold than hot. Throttle doesn't exactly 'hang' but it doesn't come down as fast as it should and half the time she'll idle high and the other half she won't.
Low down she pulls like a steam train, but doesn't seem as strong above 3000rpm as I'd have expected.
800km into the running in I haven't taken her past 5500rpm yet so can't comment on the top end.

So whaddaya reckon?
Should I put a little washer between the circlip and the plastic spacer on the needle?
Or should I open the 'air' screw a quarter turn more.
Or both.
Or something else.

I'm getting bored of taking the tank off, so I'm asking first this time instead of using trial and error.

Thanks for your interest.
John

[boz]

Could I ask what bike you are running?

[hotcam]

I haven't taken her past 5500rpm yet so can't comment on the top end.

Or the midrange, apparently.

This is my gut feel chart:
Main jets are the affect full throttle above about 6000-7000
Needle mainly affects 4000-6000
Float height affects overall but mainly 3000-4000
Air screw affects idle mostly and decreasing to very little about 3000

***BUT***
Set them in THAT order or else you'll be back and forward like crazy.

If it runs better with cold air and cold engine, it's rich.

Your settings sound pretty good as they are, but the bike sounds
rich.
What condition are your rubber seals on the jet block, and float
needle unit, and float bowl? I just replaced mine and it stopped
a bit of extra fuel getting past them causing too much richness.
Now it goes a lot better...

[Yoniboi]

Sorry Boz,
Thanks Hotcam.

It's a 1990 1k

Replaced the labyrinth seals, it was the only thing I didn't list! But they were a pig to get to stay in place so maybe one of them moved a little and isn't quite right.

So richness can cause the revs to hang a little too then. Glad I posted cos I was assuming she was lean.

What rpm would you take a bike with less than 1000km on it to? Especially one that wasn't running quite right? Maybe I'm being ultra conservative???

Cheers
John

[pacer]

My bike was a 1040 with K&N pods and slipon. I can look inside the carbs to see what is in there. My cousin had it dyno tuned when he had it. I don't know your elevation, but it will be a good start. Give me some time, I am not home.

[FZRDude]

... I don't know your elevation, but it will be a good start...

.....750m above sea level......

[Yoniboi]

Thanks a million Pacer, that's really kind of you but not necessary.
My other bike has a '90FZR 1000 engine, Wiseco 1040 + pods + slipon and runs standard everything except mains (150s) and goes like a dream (except it needs new emulsion tubes.... nudge nudge, hint hint).

The FZR still runs like crap below 2500rpm although I'm starting to think that Hotcam was right and she's running rich... the mid range was strong last night and this morning (cold and raining), got rained on steady for 5 hours this morning and hiccuped all the way home so can't comment on that.

I've got chores to do today, pick the kids up for the weekend tomorrow and the little one's only two so no spannering until Monday now. I'm guessing it's a bad laberynth seal or crap in the pilot jets. Here's hoping I'm right... that'd mean I'm learning something!

John

[dragracer1951]

If it runs better cold than hot it's rich John. The cold air is denser. Thus when up to temp, it gets less air and is rich.
I would turn in the air screw a quarter turn and see what it does.
Also, there may well be a fuel leak between the idle and main circuit.
That could be the complex Oring.
What most owners fail to realize is that in these carbs, throttle position has ZERO to do with slide position and thus needle position.
Vacuum raises the slides. Hows the valve clearance? That will certainly effect the vacuum.....