over that last week or so, i have been posting about my jetting issues and i thought i had it all figured out until now.

i have a 03 ds, 50 hrs, 1500-2000 ft or less of elavation, hmf pipe, uni filter, airbox normal with the jet that came with the pipe.

to start this, the bike seemed way off on top end and when i pulled the plugs they were black. so, i figured that i was having a rich condition. So, my plan was to run a K&N filter with the HMF and rejet. ( Still concidering removing the air box and tuning, or tunning with the lid off)

but as i tore down the carb today, i was expecting to see a 190 jet or something that was big. But, the jet says 165 on it??? whereas the new jet that i have is a 170(i beleive that its a DJ)and is barley smaller than the 165. i am confused?

i ordered a 175 and a 180 that will be here tommorow, but because the new jet that i have now is a Dynojet, i am guessing that the new ones will also be dynojets.( all gotten from the same shop)

i am soo confused now. And i need the advice of how i need to set up my bike. Air box removed? lid on? lid off? jetting? and do i have two seperate brand jets? is this what is causing my confusion?

 

dyno jets are differant than standard jets.. a 170 dyno jet is not the same as a 170 mikuni jet. I used to set up my own stuff until i bought a new carb.. I went my local dyno shop for a tune up.. $100 later i picked up about 8 hp, not only wa sit set right I also knew what jet to use for diffeant altitudes. (i ride at sea level up to 7000 ft) what this did for me is 2 things 1) I got all the hp out that i could 2) i knew for a fact that it was not lean. just because a plug is black may not be accurate.. it takes a long time for a plugh to change color. when i piped my ds with stock carb & uni 2 stage filter.. i went up one size with a mikuni jet & that was really close for mine.

 

First off if you are using dynojet main jets you also need to run the dynojet needle. The stocker and the dynojet have different profiles that will affect the main you are using. If you are going to use dynojet make sure you buy the whole kit. Otherwise get single mikuni's if you are going to run the stock needle. The dynojet and mikuni jet #s are NOT the same. A 200 dyno jet is NOT the same as a 200 mikuni.

Second here is my setup. I run no airbox with the stock snorkel bewteen the carb and filter. I have an HMF with a K&N with outerwear, and HPR full race porting on the intake. This setup(no airbox) does NOT give the best peak horse power, but it does not lose you any either. It gives the best low end of all the setups I have run. I am a big boy and I need the low end torque. I run a 200 mikuni main with the needle in the 4th position. I am running at or below sea level. On a cold day its runs perfectly. Warm days it is kind of hot at idle. I thought it was a little lean at idle but my plugs look perfect. I have a 47.5 pilot but I don't know if I'm going to put it in.

I think the main thing is to keep your needle and main jets the same brand. Hope this helped. Good luck!

 

hummm

well is there any way to tell what jets i have? the one that i beleive to be the dynojet, has a longer head but smaller diamater and the only marking on the head is 170. Whereas, the one that came with the hmf pipe is shorter in length and has some symbol that looks like an R then a square? any clues on which brand is which jet?

also, i was reading on a carb site link that i found on the HMF post in this forum, and it stated that if your bike seems to flatten out and not pull at full throttle and high rpm's then that indicates that your main jet is too small. So, if the one that came with the pipe was a mikuni, then this all would make sence. The bike has too small of a jet hence the loss of top end power.(the jet that came with the pipe is a 165) (and i beleive its a mikuni by the markings stated above).

so, anyone know which is which by the markings?