Bonneville America Forums Forums Technical Forums Performance Mods IT's THROTTLE POSITION - NOT RPM! NOT SPEED!!

Arrrrghhhh!
I don't mind answering questions at all, don't misinterpret this, but read read read!

I must get 4-5 emails everyday asking the same general questions...."What jets at this rpm? What jets at this speed??? My bike runs bad when I am in 5th gear??"

Setting up carbs is done by using the throttle position! DO NOT use a specific RPM range or a certain speed. They will do nothing but get you confused and possibly into trouble.

Read this CVK Tuning guide (same as ours but a larger carb - STILL the same) AND the Mikuni Tuning Guide for reference on how to actually use the throttle with small pieces of tape for markers.

It's not rocket science (unless you want it to be). If I can do it, so can anyone else just by following the steps outlined in these pages.

Throttle position is the secret!

Ok, rant over, and it's beer thirty.

OK. So, whats the secret. Is it RPMs or speed?

Beer thirty at 7:16AM? Great googley-moogleys!!

Seriously Pat, what's the best oil for these here bikes?

It sounds like the stress of being "the man" is getting to Pat...

BTW, I get a little popping at 5k rpms, and a little flat spot 30mph .... What do ya think?

Keep her above 5K and well over 30 MPH

ok, buncha really funny guyz! Go ahead, keep sending me smartazz emails....Youz guyz are buying ALL my beer this May now!!!
I am leaving my money home. If not, I'm not gonna play with you, my mommy said you are rood and I'm taking my ball home.
har har har.

I was actually trying to help, but Nooooooooooooooo, you gotta be Mr/Ms smartbutts! (non-discriminitory nad crunching received)

















, ok, I do have a sense of humor. you buncha friutzen merfrs ducthbug scamsukers.

OK, OK, I guess we can buy you a beer or ten.

Now, about the best oil for my bike.....

At this point I bet Pat's answer is going to be:

Crisco

Ummmm.... Almost. With these carbs, airflow plays at least as big a part. With the throttle WFO and the engine loaded down so that it's barely turning, there isn't much air moving. So, with little pressure drop across the slide, it stays shut and you run on the idle and transition jets wich are fed by the pilot jets.
On the other hand, coasting down a steep hill at redline with the throttle on the idle stop, some air is still going to flow because you are pulling a huge amount of vacuum and the slides might open a little bit, putting you partly on the needles and mains.

Pat- even tho I have NEVER EVER asked you a tech question I'll still buy you a beer or three.

Phil- Have you ever tried "Harley Oil"? You might need to strap a few quarts to your trailer bud.

Boy o boy....all this drama and I can't even get an answer to my earlier question.... and what exactly do you mean by throttle position? In appreciation of all your ranting...I mean, uh, hard work, I'm sure several will be willing to buy you a beer to too.

BTW, where did you get a pic of my boy?

Greg,

Re: Crisco

Outstanding!!

Does it matter what octane gas you use?

Oh, and my pipes fell off and got run over by a truck. Since I'm short on money, I made a set out of PVC pipe using a bunch of wax toilet seals for baffles.... Should I shim my needles?????

When the throttle is posistioned on the left handle bar, the motor is running about 4500 rpm and I am in 3 gear, what jets do I use? Do I need to change jets when I use 89 octane, the motor is running at 5000 rpm in 4th gear and going 65 mph headed west into the wind? Sometimes when I am flying to Alaska or Chicago, I have to change jets in Seattle or Mineapolis. But they won't let me take needles on those jets much less change them. Do I really need shins on my needles? I have shins on my legs, sometimes I bump them and it can hurt. I have never tried to pull a vacuum with my bike, does that mean I can't coast down hill on the red line? I hope not because all the lines on the roads are either white or yellow. The pressure I usually get is when they tell you at work tomorrow what they tell you what they want done yesterday. When that happens, what jets should I use? Because it appears to me that the throttle is still positioned on the right handle bar grip and I don't think I should change that. Or should I?

Soren

I took the red line to Dupont Circle in DC once, or was it the blue line?

As long as you didn't take the pink line to DuPont Circle I think you're ok. Phil, what the heck were you doing in DuPont Circle anyway? If you were checking out the 'nightlife' then I might start to wonder about you and Yota.

Throttle position why didnt I think of that now Pat seriously I do have a question
Whats a carberator?

We had no idea about 'that area' when we booked rooms in the St. George hotel last year!

A week's trip to DC was my college graduation present from Janet....

roundy, throttle position means if your carbs are facing fore-aft or side-side!! Cause the venturi effect is multiplied by having the carbs turned side-side even though the airflow INTO the engine is SIGNIFICANTLY REDUCED for some odd reason!!!!

I bet that trip added to your education...

I grew up in the DC area (NoVa) and I had a few friends who used to go down there in their clubbing days (not that there's anything wrong with that...)

Did you go too???

'fraid not, I was never into going to clubs. Sorry to disappoint ya

I didn't figure you were the bar hopping type.

Not to worry about carb tuning info, Pat. The next Bonnys will all have injection. Let 'em get their own remapping software!

Guys, you are hilarious....Angelis

I love you guys, seriously. I tried drilling my slide, but it just tore my shorts on the way down, and I didn't seem to go any faster. If it hadn't been for you, I'd still have all that thread wrapped around my needles.

Okay?? now I'm really confused, I know what the throttle is, and I've seen some needles in a sewing kit (although I don't know how sewing can make my bike faster?) As to the slides, well I guess the down hill boost adds something to the acceleration... but what I can't figure out is all this talk about jets! My bike has an internal combustion engine, not jets, is this something I should get? Does Brent sale them? Do jets go faster... Pat's site doesn't really go into the differences between jets and regular engines so I am totally lost here!

LOL

No problem, with the throttle on the left you'll either be riding a metermaid Servicar with a Linkert carb or a pre-'28 Indian with a Shebler. Either way you'll have a proper "highspeed" mixture screw. Don't know why they call it that, the Servicar won't go much over 50....

Quote:

---

When the throttle is posistioned on the left handle bar, the motor is running about 4500 rpm and I am in 3 gear, what jets do I use?

---

Soren, I think you will want a Jet helmet, since it sounds as thought you are sitting on the front mudguard.

I have the same problem when I fly to Chicago, I change jets in Atlanta, but they always have three guys on board who say they are pilots, sometimes they change themselves, which is nice. My main jet is a 747 when I go to Chicago, but I have to change to a DC9 main jet to get to Tulsa. I had shin splints once. Has anyone had to change splints? Sometimes when my bike is running at 4K rpm, I have to slow down for traffic, I change jets then. The jet is attached to a lever & I use my left foot.

OK Pat,
I get it. So, when I am at 45 mph, I get some sputtering and burping. Do I need to drink my beer faster? Or should I keep it hidden behind my windscreen a while longer between gulps?
I'll tell you more about the "sputtering" in Georgia. Very embarrassing.

Try a 145 main straw. It may increase the burping, but the sputtering will go away.

I just drink ten beers really fast BEFORE I ride. That way I don't have to worry about bringing a straw or wind screen....Burp!

Quote:

---

As long as you didn't take the pink line to DuPont Circle I think you're ok. Phil, what the heck were you doing in DuPont Circle anyway? If you were checking out the 'nightlife' then I might start to wonder about you and Yota.

---

there in lies The Crisco
mert

cute kid!

After getting to the end of this thread, I can now say I have taken a trip around the world. In the same day to be exact.
Pat, the original purpose of this thread is great and thank you sir.
I would like to try one of those homebrews. When I make it to Dansville to visit family I'll be looking you up.

The carb should be positioned so you can operate it with your left hand to make striking the lighter much more natural. Left handers reverse this.

Hey Dinq, I have a question, Which weighs more......a ton of bricks or 2,000 Lbs of feathers? ......Angelis

Phil,

I'm hardly the expert around here but no one seems to be answering your question so I thought I'd jump in with my tuppence worth.

The head mech for the old Trump site here in Buffalo just pulled out of the driveway half an hour ago with my bike to do the 20k check up and other work. We got talking. He told me that the difference between the Mobile T-1 or whatever it is that Triumph demands we put in our bike and the "non-Triumph" Mobil equivalent, is the sticker on the bottle. It's marekting hype; same oil exactly. Anyhow, I've been using Valvoline 4-stroke oil for over two years now and I get better transition between gears than I did with the Mobile stuff and at $4.00 a quart too.

As is the case with a lot of the stuff I've done to my bike, Gary James is my reference. He says he went and did the research and it specs out as good or better than the recommended Mobil stuff. I tend to take people at their word if they throw it in their bike too and if there's an anal retentive guy out there that beats Gary for attention to these kinds of detail, I haven't met him yet. So anyhow, I use the Valvoline 4-stroke 10W-40 (I don't have a bottle sitting around but I think the Prod. # is VV 740) in the early season and to clear out the grunge from the bike sitting. Then after about a month of riding, I swap it out for the 20W-50. (Prod. # VV 743) Also, in both cases, I substitute half a quart of Lucas Oil Treatment for half a quart of the oil.

Hope this is useful.

BB


http://www.valvoline.com/pages/products/product_detail.asp?product=76

But when you go down to a climb at lower gear and high rpm with totally closed throttle the depression valve (the one with rubber umbrella) will start to rise at near 3000-3500rpm.
So it's not only controlled by throttle open, but also from revving range...