Over 11,000 miles. Ride as often as I can, the smiling thing I do inside, no bugs in teeth.

I'm with Musky on this one...if it ain't broke......

M7

Bowhunter leave that baby alone those numbers are awesome and if it runs good that's even better. I have faught with mine for a long time to get it running right and had to beat SVS in the process. My last run I was 75hp 97lbs torque and A/F was acceptable. I run a 172.5 main, needle on 3 with two silver washers, 40 pilot, and Baron's PMS out 3. I have stock ported manifold, BAK, and Bub Stubbies with torque cones so you see any mods you make can do much more for you number and you could create an SVS problem in the process. RIDE that baby man.

Looking pretty stout there Bowhunter.

bowhunter4265 wrote:
Thanks Gram,
is the lambda curve any issue here, should I be adjusting something..
Was thinking the needle down one from the blunt.
Seemed like as it burned off the accel fuel it leaned out till the needle got the fuel back in at WOT..

Actually, I think the lambda is what he based his recommendations on. HDs and other big V-Twins are made to run richer than a R*. If you try to run a R* as rich as a harley needs to be, you will get SVS for sure. So don't do that

It looks normal to me. With that HP and Torque you should consider yourself pretty dead on. If you are running a stock carb you totally nailed it. If anything, looks like you might be a little rich on your PMS settings.

But, that does not mean your are off on the PMS. I tend to jet slightly richer at idle/low rpms to help keep the bike cool.

Gram

Thanks for the input, will leave the carb alone til it gives me problems.
Next thing on the list is backrest I got off delphi R* forum..
Than get rid of the AIS pump, its blocked off as far as the inlet, just need to ditch the pump and close off the ports.

RoadstarB wrote:
Leaner Gram? I'm running way too rich, everyone says they are set up way rich from the factory, i'm going to try some adjustments tomorow, i've jetted my old HD Sportster and several older yamahas with twin carbs so I figure the R* carb won't be a hard challenge, i've got the Baron's BAC that the dealership installed for me, but I have no idea the settings, but the bike had run great untill the past couple of weeks it has gotton worse every day and today would hardly run, I used to run my Sportster a little rich and it never hurt it like it is the Roady

I don't know what your settings are RoadstarB, and I have heard lots of foks talk about R*s being too rich from the factory, but I don't agree with that. I don't want to end up on the bottom of a dog pile so I just keep my mouth shut .

The following is my OPINION based on my experience jetting bikes and testing A/F mix with my tester on each one (both before rejet and after).

I have tested more bikes than I could ever remember or count and I have never tested a stock Roadstar that was rich from the factory (regardless of year). If they were, they would never pass EPA testing. I think that is predicated upon two things.

1) 04 and later have a tendancy to develop SVS which is one symptom of being too rich, but Yamaha redesigned the heads on 04s and they have a natural air swirl going into the heads that never existed on 03 and earlier. The manifolds on 04 and later is also much larger internally so pressure in the manifold is lower. Both of these things lead to better fuel suspension in the mix and less turbulence. So 04 and later are more efficient as a result. Good thing overall, but now the bikes are running cooler at low rpms and I personally think that has something to do with the svs problem. The better supension of the mix at low rpms is cooling the valves down more than the 03s and earlier could.

2) Yamaha R&D spent a TON of time (and money) getting the needle in the stock carb to be dead on for passage of EPA standards. When the 04's came out, the engine was larger and at some point was going to need more fuel. With CV carbs, the flow and mix into the carb stays pretty consistant so the lower rpms into midrange would remain good. The only problem would be high RPMs where the main would end up being too small. Since the needle regulates nearly all running except for wot (or close to it) they simply popped in a larger main (don't know about later years, but 04s have exactly the same needle as 03s - I measured them both extensively to be sure). The main in an 04 is WAY to big for that bike, but the stock needle is so fat that it never really gets out of the way, so it works. This is a real teller.... On 03 and earlier, when you change out your airbox, pipes and needle you have to rejet and increase the size of the main. On 04 and later, you have to REDUCE the main size. Get a needle in there that can get out of the way and the main has to be right.

Thats a long explanation. Sorry. I thinks its just easier to say 04s and later are rich from the factory rather than say all that. But its important to understand if your rejetting.

btw... Kehein (the carbs on harleys) sued Mikuni for building a carb so similiar to theirs, so it will be pretty familiar once you get in there. One big difference is that the Kehein pms covers a lot wider range of rpms. In fact it affects the entire rpm range. Ours only affects very low rpms.

Gram

Gram thanks for that info I am putting that in my carb book. Really great info to have! Thanks again!

Great #'s! Posted 74hp and 94fpt on my last run. Would love to have had that extra 7fpt , but , like Gram mentioned , you're probably at your limit, so enjoy! BB

Let me see if I understand what I'm looking at.. the lambda measurement is for the air/fuel ratio right..well gasoline is optimal at 14.7 which equates to 14.7 lbs of air to 1 lb of fuel so looking at the reading he got would you say he's a little lean in the low rpms the a little rich between say 2500 to 3500, the just about dead on everywhere else..Is that right..