I have a full yosh system, k&n pro-flow wi/ outerwares and no air box lid. I jetted the raptor last week at 160(3 turns out)/165(2 turns out), 25 pilots . I have been pretty happy with the way it runs, has good power through every gear. When I first jetted my plug looked good. I bought a new plug and put it in, went out riding for maybe 30 minutes. Checked it this morning and its looking really lean, I mean this thing is white. What should I do to get this plug looking normal? Change my screw mixture ratio?

 

o ya im on the 3rd groove from the top also.

 

the 3 turn should be on the 165 and 2.5 on the 160 and you probably don't have enough time to color the plug


Pat

 

How much time would you think it would take to get a good plug read?

 

You need to do a WOT test. Get going in third gear or higher at full throttle. Hold it there for 10-15 seconds. Then pull the clutch in, hit the kill, switch, and cost to a stop. This will test the jetting on you mains. Then move the needle to a position that gives you good throttle response. After that work on jetting you pilot circuit. The pilot jet only involves idle and just off idea readings.

Hope this helped little.

 

I already have good idle and good throttle response. So after the wot test I should get a pretty true plug reading? I have to say Ive never heard of this method, has anyone else used this?

 

Yes. I agree with what both have said but with all the detergents in gas nowadays plug reading is very hard. I don't know why the GYTR instructions have you adjust the screws that way, I think it might be a mistake but then I have also seen somewhere that it is not important that they are proportional.

 

Ok well I guess I'll try the wot test and see how they read. If it still looks lean then I suppose I will try readjusting the mixture screws. I've noticed alot of people using 2 1/4 L 2 1/2 R mix. Should I try this mixture?

 

1/2 hour is not enough time to get color on a new porceloin of a plug. You want to read the base ring anyways. The grounding strap is connected to the base ring. Check the color on the base ring for the jetting. On the ground strap is where you look for proper heat range on the plug. There will be a change in color at or near the bend of the strap if it's in the proper heat range. Detonation is down inside the porceloin area. Check with a magnifying glass to check for signes of that.

Plug reading.

 

Thx wshrdskin, very imformative and helpful article. Im gonna go put some time on my bike today and hopefully will get a better reading later. Thanks all