noob question - Running lean

i have no good way of putting this because of my bad english :? but i am hoping that you can help me here

My plugs are indicating that my bike is running lean (xj 700 maxim) and it has i am hoping that these motors are suppose to have more power than mine has :lol:

How do i make the mixture ritcher (for dummys)???

i know there is one big screw that i can adjust with my fingers under the carbs for all 4 carbs( not sure what this screw is called ) & there is also 1 screw on the lower part of each carb facing right/back on the right side & left/back on the left side...if these are the fuel mixture screws, witch way to turn the screw to make the mixture more ritch ( clockwise or counter clockwise) ??

Best regards

Halli

 

Wooa, the big thumb screw at the back between the carbs is the throttle stop, used to fine adjust the idle (1050 rpm) the other screws you mention are the carb bowl drain screws, the pilot mixture screws you adjust the mixture with are on the top front of the carbs (might be covered with a plug) you turn them out / counter clockwise to enrich the mixture, turn them in fractions of a turn.

 

Thanks for the quick reply

 

Ok still nothing has happened.... i am not finding the screws :? ......

there are 4 screws( flathead ) on the link for the choke bar... are we talking about tweeking those or am i as lost as ever??

regards

Halli

 

Pics would really help this thread

 

Your pilot mixture screws may still be "capped." From the factory, they had little brass plugs blocking access to the screws. If that is the case, the little brass plugs need to be drilled though JUST FAR ENOUGH to break through them (and not dig in to anything underneath.) Then you run a small sheet metal screw into them and yank them out.

Before you start fiddling with carb adjustments, have you checked, for instance, your valve clearances?

 

No i have not checked my valve clearences(Like i said... a huge nooob)

Waht i am conserned about is that my plugs look white & dry... & i have never driven a 700 bike that is this powerless.... i would have smoked this bike on my old chopped 500 shadow :? Also i am getting the feeling that it is running a little hot


but where would these plugs be located and to i have to remove the tank to get to them ??

any one have any pics??


Thanks

Halli

 

Then don't start screwing up your carb adjustments. You can't properly adjust the carbs if the valves are out of spec. It could also account for the "lack of power."

Get the valves in spec; then run a compression test.

THEN worry about adjusting the carbs.

 

But would valve clearences couse the plugs to go white :?

 

Indirectly it is possible, yes.

You probably will need to service and adjust the carbs. But in order to do that, the valves will need to be in spec. Further, if the valves are way tight, it will affect performance, power and long-term health.

Don't get your carbs all out of whack trying to "adjust" when you haven't dealt with the prerequisites; or you'll just end up making it worse and getting even more frustrated.

 

More to the point would tight valves while running lean increase your odds of frying your mill? Yes they will. The 4 CV Carb bikes have very little tolerance and valves ultimately set the vacuum the carb gets-which in turn meters fuel in, so as Fitz says start with the valves then carbs. The valves are easy to check, feeler gauge, 19mm wrench, allen wrenches, and not as hard as you might think to adjust.

check this out:

http://xjbikes.com/Forums/viewtopic/t=14827.html

 

SHI..... this looks like a serious opperration

 

No way man! I am a very methodical (ie read slow) mech, and it normally takes me a long time to do a simple operation (like an oil change). Of course I always find more to do when doing one thing, but to the point I usually take about 2 hours to do an oil change-simple stuff right?

Checking my valves took me 30minutes, and adjusting them took 3 hours with one sticky shim accounting for most of that time. Really it's not as bad as you might think and any problems you encounter you just need to come here and ask and we'll get you through it. Believe me you WANT to do this yourself as it saves $$ and the shop's don't always (or even often) do it right. Plus this is just step one to getting your classic in top shape, but once you do basic maintenance will keep you riding on the cheap and easy.

Jump in You can do it, and we'll get you past any bumps in the road. BTW the supplier on here XJ4Ever (top right of page)is the best source for parts and tools-check him out-he has the valve tool for holding down the buckets to remove shims and I made a shim pulling tool you could make yourself that makes it easy. The second time I went through my valves it took me 1/3 as much time as the first.

 

Well this is actually my daily ride :/ so i dont want to jump into anything that i would not be able to finish in one short sitting ....

i plan on tearing the whole bike apart next winter.

the previous owner took the bike around the whole country(iceland) twice last summer without so much as an oil change and did not take good care of it at all & the bike sat outside for a whole snow winter before i found it.

When i got it a the beginning of this summer it was not running but all it took waslug changing, new battery, oil change & some fresh Gas and i have been riding it every day since but lately i have been expirencing a lack of power( maybe i am just getting more used to riding the bike) but when i pulled out the plugs i saw that they where kind of white & dry so i thought that it was running lean since the bike has been ridden every single dry day for the last 5 years.

also i think i have to change the top gasket on the motor if i tear it off and parts for the bike are not that easy to come by here


here is the bike anyway

Regards

Halli

 

Hey. My XJ is my Daily Rider as well, and I had never done the job before, and I got it done in one sitting. Really, promise, you shouldn't have any trouble. (You should buy a new valve cover gasket, yes, but that's not a "head gasket" which you might be confusing it with, which is a much more serious affair.)

 

Normal maintenance, and basic repair parts are as easy to come by as clicking the XJ4ever banner in the top right corner of every page.

Ghost

 

You're in Iceland? Chacal should be able to ship international.

I had the same issue with mine. Daily rider got last year. It "had been" kept up over the years but the old man that sold it to me only owned it for a short time and did nothing to it.

With new plugs, a couple back-to-back oil changes and fresh gas it did great last summer and this spring started to run weak.

Without knowing anything about 4 cyl bikes I've done valve clearance + carb clean and tune in the last three months and I can barely hold with the power it has now. Just followed the XJ experts advice on here.

 

Have faith!! You can do the valve shims yourself!!