4/6 EGT temps?

[kawhead]

imo  thats not the issue but i've been wrong before......

[gixxer6]

Being that the 1.8 needle and seats were $20 each, I decided to try the 470 mains.  I installed them, put in yet another new plug, and ran WOT for 4 seconds.  This time the dull/shiny line was right in the middle of the bend of the ground strap.  (I'll be returning the needle and seats...) 

I took it for a short ride.  It still doesn't make much power, but it's definitely different.  It's only running a little over 8000 rpm, and seems a little rich.  For some reason, the right side cylinder runs around 200 degrees hotter than the left while cruising mid throttle.  At WOT they even out more, and I was seeing 1200 degrees.  When I pulled the plugs, the insulator is a real dark brown on one side, and a light tan on the other.  I don't know what that means??? 

I went with 470's with plans to turn the adjustable main in to lean it out.  (It's still adjusted full rich). 

[kawhead]

470 plus 90=580.....470 plus 1/2 turn from closed=515     thats were i'd try it again....my merc service manual says 1 turn = 90, no effect out more than that....

[gixxer6]

That's exactly what I was thinking!  I adjusted them to 1/2 turn out, and WOW does this thing FLY!  It pulls the full 9000 rpm.  I didn't hold it WOT for long, I get nervous when I see the EGTs go up to 1200 degrees and let off... 

The right cylinder is still running a lot hotter than the left.  Any ideas why???

Thanks all for the help! 

[sprocket]

It sounds like you have a air leak. I heard of different brands running two different jetting but not on any Kawasaki engine that I ran both plugs should be a nice golden brown if it's a little on the dark side both plugs you'll be fine. Make sure the carbs you use are exactly set up to each other including throttle pull back ( slides move at the same ). 470 seems rich 350-380 with one turn out 35 pilot. I have to ask do you have a carb chart from Mikuni it would be a good reference or Aaen carb tuning book. The chart will show you what's been tested already you may have to adjust a little but that ain't bad. Remember your engine is air compressor the more air more fuel more exhaust an old friend said that to me when I raced jet skis back in the late 80s.

[kawhead]

try switching carbs from side to side to see if the hot cyl is in the carb

[gixxer6]

I switched the carbs (slides and chokes included).  The right side still runs hotter, so it's not the carbs.  I switched the EGT probes from one side to the other to see if there might be a problem with the EGT's.  But I didn't get a chance to run it. 

[kawhead]

how much hotter and is that the new piston?

[gixxer6]

At idle and just over, the right side is only slightly hotter.  In the mid range, just cruising, the right side is around 200 degrees hotter.  At WOT its 250ish.  The right side is the one with the new piston.  The left side didn't look very old, the piston and cylinder both were in excellent shape. 

Another thing I noticed is the right side seems to react a lot faster.  At WOT the right side shoots right up to 1200ish, and the left will slowly climb. 

[kawhead]

hhmm....about down to exaust pipe...when new 4/6s had some pipe issues...one was not flaired/fitted correctly just insde the head pipe...

[gixxer6]

Aaen pipes on this one...

[gixxer6]

It looks like the temperature difference is a problem with the EGT's.  I swapped the probes from one pipe to the other and sometimes they would read the same, and sometimes the left cylinder would read hotter...  The probe wires were in rough shape when I got them. 

I ran it fairly hard, and the temps only went to around 1100. 

I guess my next step will be to get some fresh un mixed gas in it and try to dial in the mains.  It must be really close, because it runs really good, and pulls REALLY hard!  You should see the smile on my face after riding it.   

[sprocket]

Glad your smiling. Here is something to think about 2 different grades of pistons can cause different readings on heat. What I mean about grade is the material making of each piston is different even though they are stock pistons, the Materials made from each other are different this is where the heat comes into effect that can cause different readings

[kawhead]

i agree on the piston material sprocket,expansion rates,etc.sounds like you're close on the mains,you want to be set up so on a hot day you can lean down 40 pts or so, 40 richer when its cold.

[gixxer6]

It was in the single digits when I was running it last night.  I'll most likely be putting in smaller mains so when the temp increases, I'll have room on my adjustable mains to lean it out. 

I still don't know what to think about the inconsistency of the plug color.  Anyone seen this before?