Re-jet 82 xj 750- need help or ideas

Hey all, I'm the new guy here. I have an 82 Seca 750, I yanked (actually cut in many pieces) the air box, and soon found out that I need to re jet the carbs now. I plan on going with the pods and am going to chop the exaust. Does anybody know which jetting stage I should use 1, 2, or 3.

Do any of you have experiance in this, or have any better ideas?

Btw: jet kits cost about 90$ (and I'm broke) , does anyone know the size I cold drill out the jets instead?- I'm a machinist

 

You would use a stage 3 for a chopped exhaust and pods. Chacal has just the jets for sale. The equation on this site still had me running too lean I was at 128 mains and 42 pilots but need to go up on the pilot again.

 

Thanks! Looking forward to getting it back on the raod.

Btw: Did this help out quite a bit, and how does an XJ750 sond with open exaust?

 

I have a similar question on my xj650!!! 110 on the mains and 40 on the pilots. stock air box, aftermarket Jardines with custom baffles. My plugs, after a few chops are white as they went in.. Where do i start?
dqnjuan has only head pipes plus pods and 128 are too lean!!!
What defines the Stages 1,2,3???? where is the stage guide???
HELP

 

not sure what the diff stages are, but with just a set of slip on's, you shouldn't need to re-jet. just colortune.

 

Somewhere on here I heard if you stick with the stock collector - you don't need to rejet.

Correct?

 

if you have the stock headers, and stock collector, no change to your mufflers should warrant a re-jet.

 

My Mufflers flow very well and are louder than stock. I have turned the pilot screw 3.5 out which give me a nice color at idle but when i do a plug chop, they are WHITE. I mean brand new white. I did it 3-4 times to make sure and put 30-40 miles on in between. I ran the bike hard in the top of second or third, killed the power and coasted home, pulled the plugs and WHITE. Is this the correct way to check them??

 

I was lean at idle mostly but white plugs as well and now doing the top end from burning the rings on one cyclinder...you mod and then jet to fit thats whys its such a tideous process but dont want to end up like me.

You have to find the right combo of jets and needle placement to give you your tan plugs and the best performance that it will allow. Each engine will be different but if you find someone with a similar set up and rejet with what they have you know youve got a decent start.

 

From what I have heard, the plug colors change very quickly.

When you first crack the throttle open, you get a lean condition. Always. It has to do with increased air flow, but it has to wait on the fuel flow to catch up with it. Fuel injection doesn't have that carb lag because of that simple reason. Much faster to increase fuel flow.

I think a chop is supposed to be done at the speed/gear/rpm that you mostly drive at, so that you can tune for that specific combustion.

 

I'm going to order +4 so 114 and +2 so 42. I guess we shall see!!!

 

What exactly is colortune?

My bike was getting hard to start (spin and not fire), I changed my plugs- went to a hotter plug... made it worse. But it still started and ran strong.

Pulled the carbs to clean them, hoping that was the problem- were pretty clean.

Like any good redneck, I ripped the airbox out and decided to go with pods to avoid hours of aggravation.

Now with no filters (just trying it out in the garage), I had a heck of a time just trying to get it to start. I finally did with the help of alot of ether, but it hardly ran and would not idle.

 

ooohhhh... a redneck. in that case, take some electrical tape and wrap it a few times around each pod filter to restrict the air flow. easier than re-jetting. lol.

colortune is a special spark plug with a glass window to allow you to see the cor of the combustion in the cylinder. you adjust your air/fuel mixture to get the correct color.

 

Where do you get a colortune plug? And how much $?

I just put some colder plugs in it, and it fired up easily and ran great.
If I use pods and leave the exaust stock, will it still run too lean and burn anything up?

 

I was reading your blog about your bike. Sounds great. But I did not get to see the finished pictures... my dial up is from the mid 1800's and takes forever to load one picture, much less the whole album. Did you get everything done the way you hoped?