Can you give me suggestions for a starting point for jetting? I have or will have the following:

2005 Roadstar 1700
Exhaust drilled out to stage 3
Ported manifold (hand ported)
Poor man's bak (drilled airbox with K&N filter)
Dynojet jet kit
Close to sea level altitude

The instructions, as I interpret them, say to replace the pilot jet (orig 35) with the DPJM037,
replace the main jet (orig 182.5 Mikuni)with DJ195,
replace the needle with Dynojet needle - clip on 4th groove from top (blunt end), washer above clip, spacer then washer below clip. ie. so from top (blunt) I have washer, clip in 4th slot, spacer, washer.

I'm a little confused because as I'm reading through the posts on jetting it seems like the recommendation with main jet is to go to Mikuni 170 (which would be equivalent to Dynojet 180 or 185 from the conversion chart). In that case, my DJ195 would seem to be too large.

My kit came with the following mains DJ165, DJ170, DJ175, DJ190, DJ195, DJ200, DJ210

This is my first time messing with jetting so of course I'm hoping to nail it the first time and not have to mess with it again (sure, that'll happen )

What's a recommended starting point for my setup?

Thanks.
Craig

kidcurrie wrote:
This is my first time messing with jetting so of course I'm hoping to nail it the first time and not have to mess with it again (sure, that'll happen )

Then you should leave it stock.

What you normally see recommended is for a free flowing airbox and pipes. You have a mix that difficult to "get it right the first time".

Try replacing the needle (don't need to remove the carb for that) and put the new needle in. Set the clip to the fifth slot and do the WOT test to see how it runs with the stock main. Then go up or down as you need with the equivalent DJ jet.

Doc

The 180 seems to be the go to Dyno main but that doesn't mean it's the only one that will work. The 195 is too big. Leave the pilot stock. You could try the 175. The WOT will tell you if you are too lean. Put the 175 in, set the clip in the 5th groove, and do the WOT.

Or if you just want to put something in there one time and not tweak then a 180 with the clip in the 4th will run OK.

Thanks for the responses. I was kidding about getting it right the first time (I guess it didn't come through). That would be nice but I'll take it off/apart as many times as needed to get it right. I already have the carb out now but it's nice to know I can change the needle settings without taking it out.

I'm pretty clear on the needles as you've said to move it to 5th slot and too WOT test so I'll move it from 4th to 5th before putting it back on the bike.

Still a little unclear on the main jet. I will put the 182.5 Mikuni back in as you've both said that but what about the comment about trying the DJ175? That is smaller than the Mik182.5

That's what's confusing me as well as other posts have where the recommendation has been 170 Mikuni. In general, when air restrictions are lessened (ie. poorman's bak, real bak, Speedstar, etc. - and I realize these are different levels of air) do you use larger numbers than stock or smaller numbers? Seems intuitive that larger jets would be used because more air can be pumped through but those aren't the general responses.

Sounds like my current modifications aren't enough to warrant jet changes (unless the WOT says otherwise) and I can just get away with an adjustable needle, maybe having to adjust the slot after trying it, and tweaking the PMS for now. Simple enough.

I'm asking questions and trying to understand the general theory on this because I hope to change to aftermarket exhaust and intake at some point.

Great site by the way! Where else can ya ask questions at 11:00 PM and read answers at 5:00 AM? I don't post much but I read a lot.

thanks and ride safe.
Craig

First.. kidcurrie. I used to run the poor mans BAK also, the 180 main was fine,but I was running the cobra lowboys, the 175 was a hair to lean for mine. I did the 37 pilot and believe it or not it really killed my mileage. Went back to the 35.

kidcurrie

I didn't say to put the 182.5 back in I uggested you could put a 180 dyno main in. You can't just look at the main jet size by itself. You also have to look at the stock and Dyno needles. Huge difference in taper. IMO if you go with the Dyno needle and put the 182.5 back in you will be way rich.

I suggested you leave everything as is but the needle and do the WOT. No use going full bore into the carb if you may not have to.

I suspect you will be too rich for the reasons Musky stated but it will give you a starting point and a feel of what the bike feels like when the main is too rich.

Or you can use Blackroadie experience and try his setting out.

Doc

Ok. I think I get it now. Since I have the DJ175 I'll put that in and try the WOT. If too lean, get DJ180.

I wasn't taking into account the different taper on the needle when I was asking about going to a smaller jet earlier so I wasn't comparing apples to apples. Thanks

It's all a learning curve It becomes much clearer once you get in to the carb and start working with the parts and see how everything fits together.