Best timing for '90 k5?

[NZ500]

I've just finished doing a complete rebuild of my 1990 kx500. I took a photo of where the timing was when I pulled it apart. But after seeing some of the dodgy repairs on the bike I'd say the last owner was a bit of a muppet and it's probably not right. Currently it's just to the left of the mark. it's completely stock with fmf gnarly and pro circuit muffler. Any suggestions as to where it will work best?

Still can't ride it because I have to sort a custom front sprocket (so chain clears the case, I welded all the side up while it was apart) and new spacers for the rear wheel which was miles off, had spring washers between the disc and hub and chewed out the front right of the swingarm. Oh the joy of old bikes haha. I've got a new front sprocket that's 10mm thick for a late 80s big cc DR I think. Will put photos and part numbers up when I have that sorted out.

[Roostmad1]

run it in the middle,it should have three marks

[sandblaster]

+1 Mine runs great in the middle.

[Friar-Tuck]

 Me Three! Center mark.
But to qualify that all I Have is an aftermarket pipe, air cleaner, bolt mod and cleaned up the ports.
  Tuck\o/ 

[sandblaster]

Me Three! Center mark.
But to qualify that all I Have is an aftermarket pipe, air cleaner, bolt mod and cleaned up the ports.
  Tuck\o/ 

Me to.
I should have said that.
Sorry

[NZ500]

Cool. thanks very much

[kwakman]

left hand mark is for bottom end, right hand mark for top end bands.

[martinfan30]

I just buttoned up my 500's engine yesterday. I am going with a gnarly desert pipe, which from what I read is great bottom to mid, and smooths out the top hit.

So my logic was run it closer to the right hand mark (slightly advanced) to help keep the top end .

Am I pissing in the wind here with this thought?

[Hillclimb#42]

I think the retard line is for better top, and advanced is for better bottom. Depends on your preference and riding area or track. Try them all 

[Motorrad]

I just buttoned up my 500's engine yesterday. I am going with a gnarly desert pipe, which from what I read is great bottom to mid, and smooths out the top hit.

So my logic was run it closer to the right hand mark (slightly advanced) to help keep the top end .

Am I pissing in the wind here with this thought?

Gnarly desert is mid to top.   (same as a fatty).   

Your thinking of gnarly woods pipe

[martinfan30]

I just buttoned up my 500's engine yesterday. I am going with a gnarly desert pipe, which from what I read is great bottom to mid, and smooths out the top hit.

So my logic was run it closer to the right hand mark (slightly advanced) to help keep the top end .

Am I pissing in the wind here with this thought?

Gnarly desert is mid to top.   (same as a fatty).   

Your thinking of gnarly woods pipe

Oh ok... So if I'm advanced on my timing, then this pipe should work well everywhere...

[kwakman]

Right.If you are using the desert pipe, you would be best advised to move it to the right hand mark,( anti clockwise).Your train of thought is correct, but what retarding(R hand mark) does is moves the combustion process back, which enables more heat to pass into the pipe, raising the temp.The increase in temp means the waves in the pipe can move faster and gives a more pronounced effect in the top end of the 'band.
OR, by advancing the ignition, (L hand mark), you give the cylinder more time to have the mixture burn enabling a greater pressure rise in the cylinder, but having increased the spark lead time, you get increased pumping losses at high rpm.
If you move yours left, you will not have pipe and ignition in sync, and will lose some of the benefit of having the desert pipe. As long as you stay within the marks, have a play and then ride it and see what suits you best. Ultimately though, if you want fat bottom end, I would change the pipe to a Gnarley woods pipe. part no 020055.HTH.K.

[martinfan30]

Right.If you are using the desert pipe, you would be best advised to move it to the right hand mark,( anti clockwise).Your train of thought is correct, but what retarding(R hand mark) does is moves the combustion process back, which enables more heat to pass into the pipe, raising the temp.The increase in temp means the waves in the pipe can move faster and gives a more pronounced effect in the top end of the 'band.
OR, by advancing the ignition, (L hand mark), you give the cylinder more time to have the mixture burn enabling a greater pressure rise in the cylinder, but having increased the spark lead time, you get increased pumping losses at high rpm.
If you move yours left, you will not have pipe and ignition in sync, and will lose some of the benefit of having the desert pipe. As long as you stay within the marks, have a play and then ride it and see what suits you best. Ultimately though, if you want fat bottom end, I would change the pipe to a Gnarley woods pipe. part no 020055.HTH.K.

Thank you for the great explanation! I want the mid to top the dez pipe allows. I just want to help where the pipe doesn't by changing the ignition timing.

THanks!!!