One Cylinder Rich

[fast426]

Well this year I added dial-a-jets and pod filters instead of the stock airbox to a 2000 T-cat, (big bore ZRT motor). Last year wide open the EGT's were all the same (with a few degrees). Now this year, the sled runs awesome, but the mag side cylinder was running 100 degrees cooler than the other two. I jetted down one size and two clicks on the dial a jet and still 70 degrees cooler. I had the carbs apart when I installed the DAJ and cleaned them good then, so I doubt they are dirty. The EGT probes just went in for calibration, so I doubt that as well. They all look in the same location (they are new pipes, but they are very close to the same spot, if not identical). The only difference I see is that the cooler cylinder slide does not go up as high as the other two. They all go above the top of the throat, but the cooler one is maybee .020 lower, could thsi be the issue? Or could it just be the pod filters. How much is normal for one cyulinder to have to go down with pods? ANy other suggestions? Thanks

[snofrog]

just a guess here ... could the warm air comming off of the muffler and pipes being less dense than the cold air from the clutches be causing the difference . did you hook the probes in different pipe to confirm ? M

[94ZR580]

The only thing that matters is what the spark plugs and piston wash tell you. You made substantiual changes to the set up on your sled by eliminating the airbox, so you now have to do a complete new baseline set up. You have three completely separate systems there, each cylinder is on it's own, so each one could have different jetting requirements. Figure out what your jetting needs to be, based on plugs and piston wash, and then see what the EGT reading is when your tuning is how you want it, that will be the correct reading for oyur particular set up.

[fast426]

The only thing that matters is what the spark plugs and piston wash tell you. You made substantiual changes to the set up on your sled by eliminating the airbox, so you now have to do a complete new baseline set up. You have three completely separate systems there, each cylinder is on it's own, so each one could have different jetting requirements. Figure out what your jetting needs to be, based on plugs and piston wash, and then see what the EGT reading is when your tuning is how you want it, that will be the correct reading for oyur particular set up.
[/b]

I agree totally, but do you think it could be possible to have one cylinder three jet sizes smaller than the other two? Thanks

[900geek]

did you switch the probes around so the centre cyclinder reads on a different spot on the pyro to be sure its not the guage abit out,and you better start paying attention to your wash,get that the same on all cyclinders before you be make your final changes,and the .020 difference is all the way up from idle not just on the top,try synching your carbs when leaving the tops for a run to see if it makes a difference

[94ZR580]

I agree totally, but do you think it could be possible to have one cylinder three jet sizes smaller than the other two? Thanks
[/b]

That does seem like a big stagger, but what do the piston wash and plugs look like compared the other two? Don't lean out because of what the EGT guage says.

[CATTRACKS]

Lower compression in that cylinder could cause that,the unburnt fuel could be keeping it
cooler,cause you don't have the same amount of fire in that cylinder compared to the other two,just a maybe.

[fast426]

Lower compression in that cylinder could cause that,the unburnt fuel could be keeping it
cooler,cause you don't have the same amount of fire in that cylinder compared to the other two,just a maybe.
[/b]

Compression is the same

I am giong to synch the carbs and fgo from there.

[fast426]

Where is a pic of good vs bad wash? I am a little confused on this wash. I understand a blakc piston is a lean cylinder right?