HELP.....

ive not long finished my cafe racer project but seem to have a problem.. firstly i need to stay ive changed the air intake and it practicly has no exhaust now. looks good and sounds te bollocks but i have a flat spot mid range.
it rides fine at low revs and goes like a missle when i open the throttle but if i try to hold the throttle mid range, its flat , almost feels like a misfire. the throttle bodys have been balanced and the airflow meter has been adjusted to compersat the K&N air filter, valve clearances are ok, new plugs and leads seem to be good. TPS is working and adjusted correctly.
im at a loose end???????
its not stopping me from enjoying the bike but would like to get to the bottem of the problem.
if someone can also tell me how to add pictures to the thred i will.
thanks.

Hello!

Try this link
How do you post a picture or a movie?

Cheers

When you open a new post text box you'll see 2 picture icons on the left of the fifth group of icons. 'Host an image' and 'Insert an image'.... sounds like you did a good job of your cafe.... you should be able to work it out. If not there's a 'sticky' at the top of the General Discussion forum.

Try advancing the timing by about 4º

What did you change on the intake?

How and why did you adjust the mass airflow sensor?

INTAKE.
 ive removed the mass air flow from the airbox and fitted it straight onto what i call the plenom chamber, make an adaptor to take a K&N fitter. the mass air flow meter was adjusted to richen up the fuel at idle, before adjusting the plugs were coming out white.. to lean. now they are a grey/brown colour.

Oh dear! Looks like it might've been an SE in its previous life....

What's an SE?????

SE = Special Edition

Blue/White paint job, white wheels, white on crank and valve covers, painted white side bags and a few other upgraded odds and ends.

How did you adjust the MAF? By spark plug color?

Best I could do was vlean new plugs. Run at idle for 10 mins. Pulled the plugs and checked. Then good clean adjust mass with the Alan key . Repeat.  .. Tolk along time to get the colour I wanted. My local garage won't put it on there gas Analyser in case it damage is it

Damage what? Your bike or the analyzer?

Here's another method:
http://skylands.ibmwr.org/tom/tech/co-setting.html

The analyer. 
Any way I thought the mass air flow adjuster only controls fuel mixture at idle. After that the flap is moved by air flow from opening the throttle. My problem is the mid range????

tyetye wrote:The analyer. 
Any way I thought the mass air flow adjuster only controls fuel mixture at idle. After that the flap is moved by air flow from opening the throttle. My problem is the mid range????

it does ,the method DUCK linked to works really well , but as you say it only affects the idle mixture, the lack of power in the midrange is probably due to your modification of the intake path and almost completely removing the ehaust, this might be great at WOT , but i belive the engeniers at BMW did a great job choosing a looong intake path , this provides tourqe all the way from bottom to top end 


k- rider

A little known feature built into the brick. If you have the engine idle set at at least 1000Rpm press the green starter button if the mixture is correct the idle stays the same or increases just slightly. If the idle drops or increases significantly the mixture is wrong and needs to be adjusted. This method only works on 2V bricks not the 4V ones. A suggestion has also been made that you can use this feature as a boost, not so sure about that one.
Regards Martin.

It's been suggested that I advance the ignition timing by 4 degree.  . I know how the do this by timing the timing plate clockwise but is the any way of checking it? Ie timing light?

Yes, you can use a timing light on a K.  But the forks kind of get in the way. I've read of using a mirror but haven't tried that myself.

tyetye wrote:It's been suggested that I advance the ignition timing by 4 degree.  . I know how the do this by timing the timing plate clockwise but is the any way of checking it? Ie timing light?

You can do it by hand. Its nowhere near as critical as timing a points ignition running off a cam. Take a look at this thread.  All the info you need is in post #5 and #7.