My bike has a drilled stock airbox, K and N, and cobra pipes, and is showing some signs of being a little lean, I think.

If I don't run premium the bike runs like shit. Lots of engine noise.

On premium it runs pretty good, occasional it will cough back threw carb.

Bike is a little hard to start and you have to run it on choke for a little while.

I was going to pull the carb and see what main jet was in it but it looks like my manifold is pretty dry and has lots of cracks. I'm afraid to disturb it without having another one on hand.

Are there any aluminum manifolds still out there or are ported rubber the only option? Rubber would be OK I guess but been lurking around some and would rather not have one that collapses under load.


Also what would you recommend main jet and PMS set at for this rig? I can get to it the plug is already out of it. Makes me wonder if the carb has already been rejetted too.

jethrob wrote:
My bike has a drilled stock airbox, K and N, and cobra pipes, and is showing some signs of being a little lean, I think.

If I don't run premium the bike runs like shit. Lots of engine noise.

On premium it runs pretty good, occasional it will cough back threw carb.

Bike is a little hard to start and you have to run it on choke for a little while.

I was going to pull the carb and see what main jet was in it but it looks like my manifold is pretty dry and has lots of cracks. I'm afraid to disturb it without having another one on hand.

Are there any aluminum manifolds still out there or are ported rubber the only option? Rubber would be OK I guess but been lurking around some and would rather not have one that collapses under load.


Also what would you recommend main jet and PMS set at for this rig? I can get to it the plug is already out of it. Makes me wonder if the carb has already been rejetted too.

Get a new ported manifold from Curt. See his ad, in the Classifieds here on the forum.

A Barons kit will provide you with a multi groove needle.
You'll want a 37.5 Mikuni Pilot jet. A 167.5 Mikuni main. Put the clip on the 4th groove from the blunt end(top), and put all the washers/spacers back on the needle, the same as it was stacked up stock. Set the PMS, about 2 3/8 out from lightly seated, and you should be fine.
Since it's an 03, I'd also change out the needle and seat(float valve) while your at it, and the carb is apart.

Jet kits are like $50. I can get an HSR42 for $260ish. Makes the HSR42 a little cheaper upgrade. Thinking about maybe going that route.

The PMS screw cover is already drilled out. I opened it up 3/4 of a turn I guess that was the wrong thing to do. I thought I was making it richer?

Acceleration seems to be fine on the bike and it doesn't backfire or anything on decel. It cruises down the highway and MPG is in the mid 40's. Doesn't seem to be getting hot but the main thing I see is it has to have premium or it runs like shit. I also just worry about it being to lean and engine damage or it being hard on the motor.

Also forgot to mention I have the dynatrack 3000 on it.

Kurt doesn't have any manifolds up on the classifieds what is he getting for them?

jethrob wrote:
Jet kits are like $50. I can get an HSR42 for $260ish. Makes the HSR42 a little cheaper upgrade. Thinking about maybe going that route.

Just to be clear, the HSR42 won't provide any performance gain. It is slightly more responsive as you don't have to wait for the vacuum to respond. It will also require a bit more fiddling with as the CV40 adjusts for altitude and such. The HSR42 does not. You will also have to go pumpless (not a bad thing, just something more to do).

oh.
Well maybe I'll do the jet(s) then.

Would I be making a mistake if I just fattened up the main jet? I need to pull the carb apart I guess and see what is in there.

Need to start by knowing where you are. Once you know that, then you can make knowledgeable changes. But SKWEARpeg got you started with a good point to be looking at to begin from.

jethrob wrote:
Jet kits are like $50. I can get an HSR42 for $260ish. Makes the HSR42 a little cheaper upgrade. Thinking about maybe going that route.

The PMS screw cover is already drilled out. I opened it up 3/4 of a turn I guess that was the wrong thing to do. I thought I was making it richer?

Acceleration seems to be fine on the bike and it doesn't backfire or anything on decel. It cruises down the highway and MPG is in the mid 40's. Doesn't seem to be getting hot but the main thing I see is it has to have premium or it runs like shit. I also just worry about it being to lean and engine damage or it being hard on the motor.

Also forgot to mention I have the dynatrack 3000 on it.

Kurt doesn't have any manifolds up on the classifieds what is he getting for them?

If your headed to an HSR, then you'll have to get jetting info from somebody that messes with them. They have more stuff to change, then the stock carbs. Some by them already set up.

I'm not sure how $260, versus $50, is a cheaper upgrade, unless your already going that route. You'll need to buy the 37.5 Mikuni Pilot, because it's not in the Barons kit. That and the new needle and seat, will have you in the $75 range

By turning the PMS out a bit, you were adding fuel at the PMS hole only. Bumping from the 35 stock Pilot, to the 37.5, adds fuel across the whole Pilot circuit. Cheating with the PMS, is a short cut, not a real cure. With the slightly larger Pilot, you can put the PMS, back where it needs to be, to control the fuel mix, at idle(900rpms)

PM Curt, and see what he has going. He may need to post his ad in the Classifieds, again. He will port a new stock manifold, surface the flanges, and solder the AIS port on the manifold shut. He does a very nice job.

With the Dyna3000, set to 5k, you can use the 170 Mikuni main. It'll provide more fuel at the top end.

Yes, you would be making a mistake. Just richening the Main, only addresses one part of the whole enchilada. The Pilot, and the Main, along with the clip position on the needle, combine to handle the midrange. The Pilot and the Main, contribute, to the WOT/top end fuel delivery. Done correctly, you want to adjust all three, so they work well together.

Manifold porting in progress!
The thing has cracks the size of the grand canyon all over it so I figured it would be a good one to cut my teeth on. It has small dimples because I couldn't locate a sanding wheel this evening. I used a rotary file. It was pretty amazing how much of that thing I was able to grind away. I got a little carried away with it started to take out one of the oring groves. I also think I might goop the outside of the thing with some 3M 847. I'm tempted to put some on the orings too the stuff seals like mad.
I managed to get carb screws out thinking about rebuilding that sucker before putting it back together it doesn't look like it has been apart in ages. I appreciate you taking the time to encourage to do things right. The only thing I can put my sights on is riding this weekend but I don't think that is going to happen. Current jets are 35 165 that I can see. I guess there is another one under the plug.
Anyone know how you change your flipping password on this forum? I must be overlooking can't seem to find it anywhere!

I've been taking a few pics. If I do this right hopefully they show up below. I'm hoping maybe a dealer around here has the parts so I don't miss out on Sunday riding.

The porting job is a little fuggly I need to get a sanding disk and clean up the highs and lows. Still thinking about buying a new ported manifold.

You say it runs like crap unless you use premium gas, Do you know if it has had High compression pistons installed? Did you install the dyna 3000 or was it in there when you got the bike?If it was in there when you bought the bike see if it is set on A or B settings. If it is on B settings there is a chance you have HC pistons. If it does have HC pistons it will run like crap on regular gas. HC pistons are often an upgrade that is done when the recall is performed.