Jetting/Pipes

[Ron]

Due to the lean settings the constant stalling was driving my crazy. I found my self blipping the throttle as I came to each stop. It became a hastle, not to mention the danger of stalling out in the middle of traffic intersections, especially here in Atlanta. After receiving sound advise from our friends and Aprilia USA and the guys at Mototek, I decided to dive into the carbs. If you own a Pegaso, I highly recommend doing this. It's not that hard and I did it in two hours. I also changed out the pipes at the same time. I used Staintunes. Super nice, high quality but very pricy compared the the Arrows. The Staintunes were also in stock so I didn't have to wait. I'll have pictures available tomorrow if any body want to see them.

[CAS]

Hey Ron,
When can I see/hear your new pipes? What effect has the mods had on the stalling, driveability, power, etc.? I've had to live with blipping the throttle but it's a minor annoyance because it appears only when I make a hard stop-usually trying to avoid a soccer mom! The engine is probably going to cut out when I really need it. Unable to make a deal with the Boss about some nice pipes so I'm going to have to live with a rejet and the stock cans that I've opened up a bit for now. She won't notice that. Marriage can be difficult...to the Pegaso, that is. Ron, can you help me with my marriage?

CAS

[ed apriliaforum com]

Ron, please post some pics here in the discussion forum so everyone can see them. It is very easy to post pics in here.

simply type, with the URL of the pic in between the brackets

www.link to the pic.com/pegaso1.jpg

[Tim C]

FWIW, my experience with the stalling is that it goes away by itself after 3-5000 miles. My bike used to stall like crazy too, The vacuum pipes were reversed on the canister (a la bmw f650) and the dealer set the mixture screw at 4 turns out. It still stalled. So I kept on riding it and it gradually stopped. Now the bike hasnt stalled once in 4000 miles and it runs flawlessly. Based on my experience I wouldnt fool around with the carbs until youve at least 5000 miles on the bike.

Tim C

[Ron]

Cas, I can't help with the marriage thing but I can make your bike run better!

[dcousins]

Cas, I like the idea of opening up the stock cans, how did you do it? Do they sound different?
Dennis

[CAS]

Dennis,
Drilled small holes at 9 and 3 o'clock between the exhaust pipe and stainless endcap on both cans. Start small and drill a little off of the welds to make room for expansion. PS, "help" all the fiberglass out before expanding the holes to get actual volume(bicycle wheel spoke, coat hanger, etc), you might have to work the drill bit a little to expand the holes because of the lack of clearance between the pipe and endcap, work in small increments because there is a marked jump in thump from 4 to 6-7mm. The holes are around 6-7mm now. I didn't want to get any bigger because I wanted to do a rejet at the same time. Idle mix was the only prob prior to mod. Everything else is fine but I'm sure rejet should fatten low and midrange. Happy drilling!

[Iain Ross]

Cas
Am I correct in thinking that you drilled the metal behind the end cap, inserting the drill inside the small tube on the end cap? You didn't mention having to drill out the rivets to remove the end cap so I think this is what you mean.
Iain

[CAS]

Between the tips of the endcap and the exhaust there is a gap big enough for a drill bit to fit into at the rear of the cans. You don't have to deal with drilling out the rivets that hold the cosmetic end cap on the cans to do this.

[Iain]

I've just received an email from Predator Exhausts quoting £370 for a pair of stainless silencers. They are available in a road version and a race version which is claimed to add about 6 bhp. They also come with a lifetime warranty. They're going to send me more info so I'll post it when it arrives

[tduic]

Hi Ron, what exactly did you do with the carbs?
Thanks.

[Ron]

E-mail me @ rbarbani@firstamericancoil.com and I'll give you the run down on how to change you jetting.

[CharleeTho]

FWIW. After much trial and error, mostly error, for higher elevations ( above 5,000 feet) I have found the stock jetting with the air screw out 4 turns works very well.
Larger jets or raising the needles causes very rich running.