JETTING SOLVED! Could this be real?....and WORK?

[joeyputt]

+1 again for Swapmeet Louie! I agree joeyputt!

This is the way it was done and the way I still do it! It also irks me when people say what a good tuner someone is and they're refering to some guy with a dyno. Granted, the guy is no idiot but take the dyno away and let's see how good he really is! I'll go heads up against him anytime!

I build my own, I tune my own, I'll be glad to give anyone a run for their money!

+1 again for Brother Bbqb4racing and Brother Swapmeet Louie! I worry about racing guys like you more than anyone else! In my own personal experiences the textbook theory dyno racers have always been easy to out run!

[Garage Rat]

+1 again for Brother Bbqb4racing and Brother Swapmeet Louie! I worry about racing guys like you more than anyone else! In my own personal experiences the textbook theory dyno racers have always been easy to out run!

Ive gotta ask... Whats with all this "Brother" Are you Hulk Hogan or something?

[Swapmeet Louie]

Ive gotta ask... Whats with all this "Brother" Are you Hulk Hogan or something?

you just jealous he hasnt called you brother yet...

[CrescentSon]

Sounds like a hyped up jet kit to me.

Kit Includes

    * Main Jets
    * Needle Adjusters
    * Nylon Spacers
    * Drill Bits for:

That is all that is actually in the kit. Everything else looks like tuning info that could be found on the net.

    * Slide Hole Modification     (not an actual item, only mod info)
    * Idle Mixture Modification      (not an actual item, only mod info)
    * Slide Spring Modification     (not an actual item, only mod info)
    * Bike Specs     (not an actual item, only info you have in your shop manual)
    * Carb Schematic     (not an actual item, only info you have in your shop manual)
    * Carb Synchronizer Tool (how to build for $5)     (not an actual item, only info you have in the $50 mod thread)
    * Step by step instructions with photos customized to your bike.     (not an actual item, only info)
    * Installation Support - If you need assistance with installation or have a question we are there for you.    (good luck dude, we don't know?)

I'd rather buy the jets myself.

[teazer]

Yep, you absolutely can get close enough without a dyno and there are probably a few people on this forum than can do that in less than a full day with a box of jets.

On the other hand you can get the jetting spot on on a dyno in less than an hour as a rule.

Jetting is rarely "perfect" and getting that last 1/2 HP can take a long time if you go searching for it.  But it's possible to get pretty damn close to the right answer in 30-60 minutes on a dyno.  It's just a tool.  I like my jetting to be close enough but I rarely change jets for changes in weather even at the track because that's rarely the limiting factor. It's the age old law of diminishing returns.

In this case. it's just a jet kit after all and they claim that they know what they are doing.  None of us so far has tested that claim, so it's all hypothesis. Anyone that posts an answer on the theory or practice of jetting that has not had a bike on a dyno probably has almost as much to learn as I do and I'm always learning and have been for 4 years or more of playing with bikes. 

For example:
I have learned that I can get jetting pretty close on the street with a big box of jets and enough time and road, and that I can get much closer much quicker on the dyno.  I also learned that bikes that I thought feel great and crisp etc are sometimes not even close in reality and are much nicer/faster/economical after a trip to the dyno.

Is a dyno mandatory?  Hell no.  Is it a smart investment?  Absolutely.

[Swapmeet Louie]

Well, cant argue that a Dyno isn't a nice tool. I just think they are not readily available for your average cb350 builder.

Besides, this was about whether or not the ebay kit was a smart investment or not.

 I still believe that it's a waste. And would deprive the purchaser of the pride of figuring it out them selves, and heaven forbid learn something. Instant gratification is usually short lived. But, it kinda goes hand in hand with the way people think these days. Which is, why do it my self if somebody is willing to do it for me...?

[diesel450]

Yup. two schools of thought and neither is better or right or wrong. Brothers.

[teazer]

Louie, No argument that learning by doing is the way to go.  Those of us that were lucky enough to either have a great mentor or to have lots of books and magazines to refer to did learn to do somethings eventually.

My point was that for a newbie a spell on the dyno is a great investment and for those of us doing it long enough a dyno is still a great tool.  But it's just a tool and does not replace that vital human touch.  Experienced racers have all sorts of tools including weather stations to help them to get the last ounce of performance out of their bikes.

But there are not many of those guys here.  The question that Brandon asked was is a good place to start with jetting.  The answer IMHO is yes for anyone that doesn't have a lot of experience jetting a bike They will still need to fine tune it in all probability but they will get into the ball park right from the get go. 

If a bike is modified much from stock, who knows where the jetting will end up.  Should they go up on the needle and main jet or up on the main and slow jet but leaner on the needle and how do they tell what's right and what isn't?

All the advise I have read here and on most forums about reading plugs is flat out wrong and has led, in a couple of extreme cases, to burned pistons and wrecked motors. That's not very likely on a CB350 that's fresh out of the barn.

The other way to look at this is to say, screw the theory and the fine tuning because the bikes is hardly state of the art and isn't in perfect condition, so how can we make it rideable. In that case, it's probably not worth a dyno or a jet kit.  Just ride the bike and see how it feels.  Try a couple of sizes up on the main jet and see how it runs, tweak the low speed with the air screw and if that feels OK then leave it at that.

I don't race karts with pumper carbs, I build street and race motorcycles and I like them to run as well as possible at a reasonable cost.  There is no point in trying to get the carburation 110% accurate when the rest of the motor is worn.  There is also no point in trying to get to perfection when good enough is adequate.  It all comes down to how good is good enough and what is the most effective way to get there.

If they have a jet kit  for a CB350 with pods and stock carbs, I'd try it.  Same for a CB360 or CB750/900 DOHC.  For a SOHC motor with regular old piston carb, I'd go up on the mains and tweak the air screws.

On a two stroke, all bets are off unless the jet kit came from the late great Leon Moss at LEDAR.  This stuff ain't rocket science guys.  Al it takes is a logical approach and an open mind (and a large box of jets needles and emulsion tubes)

[joeyputt]

I don't race karts with pumper carbs, I build street and race motorcycles and I like them to run as well as possible at a reasonable cost.

Hahahaha! I take it that was a shot at me Brother Teazer!? I have been building and racing motorcycles for over 20 years!

I only brought karts...which are one of my other personal passions...into the equasion when we were having the forward facing carb debate a couple weeks back...and yes again when we were discussing side valve/flathead engines...and you already know that I run both pumper and Keihin slide/bowl carbs.

I was not aware that I had become your arch enemy for having a different opinion as you. I am here to share information and ideas and learn from those that I can and although you and I have greatly differing opinions on most subjects I have never called you wrong but if you feel the need to take shots at me because you have been building bikes for 4 years well then I guess now I know how you really feel.
 
Lighten up a little bit Brother Teazer, opinions are just that, and are nothing personal at all.

[teazer]

I think there's a failure to communicate here joey.  I'm not having a dig at you.  You are not my "arch enemy". 

I admit that find some of your posts and ideas a little off the wall and try to explain politely why that's how I see it.  I try to be polite and respectful and sometimes the way I write is taken out of context.  That happens. 

What I did say, was that I don't have your experience with Karts so that isn't my perspective or "come from place", so I told you where I'm coming from.  No more no less.

I don't recall making a personal comment about you or attacking you.  Lighten up dude. 

There's a lot to learn and I'm still learning after 40 years and having built top quality show and race winning bikes 2 and 4 stroke (OK so the shows were small) on 3 continents, and I continue to learn something new every day. 

As to "facts" and "opinions" that's a really good point.  That is usually overlooked. Opinions are often interpreted as if they were facts and facts are often treated as opinions. 

[joeyputt]

No sweat man, I know there are many people here all with largly varying skills and opinions but when it comes down to it we all share one thing...the love affair with the motorcycle. I admire that there are so many people here building such a diverse field of machines and that most are home builders turning wrenches out in the garage. I have always thought of guys like us as motorcycle enthusiasts, not bikers...and as craftsman, not mechanics. I know that sometimes there will be debates over opinions, facts, designs and theory, however I also feel that sometimes we forget why we are here...as people who have such a strong common bond and all share in the love affair with the motorcycle, and the craftsmanship of building our own machines that goes along with it, we should all act a little more like what we are...BROTHERS.

[Swagger]

Anyone of you intertoob-boxing champions ever mess with a dial-a-jet add on?
http://www.thunderproducts.com/dial_a_jet.htm
 

[diesel450]

Talk about sounding too good to be true.

[joeyputt]

Brother Swagger I have never used that before...I did not read the whole article as it was rather long but it looks as if they are still using the original jet with this system as an additional jet for adjustments...is this correct? I have used externally adjustable needle main jet setups on butterfly carburetors and they are very easy to adjust and work very well also.

[teazer]

Dial  a Jet or a latter version have been used for years in the Sled set.  It's a valid enough approach to a situation where you need say a #400 jet at sea level and a much smaller one, say 280 at 10,000 ft.

Not much application on a bike though.