Dial A jet tuning??? Has anyone tried it?

[hotrdd]

So I've tried and tried and tried to tune my carbs but I haven't had any success. I've read the manuals and posts from front to back but just don't have the experience to notice the difference. I've went way up and way down on carbs and I just don't feel much of a difference. I still seem to have dead sports and stumbling. I've tried throttle shops with over a dozen plugs and I just don't see much of a ring to speak of. Part of the problem may be my single K&N cone filter that feeds both carbs and homemade straight pipes with V&H baffles.

NOW, I've called around to a couple of shops in the Calgary area and they are looking at around $400+ to tune the bike. SO instead I started looking at just adding a wide band air/fuel ratio gauge for about $250-$350 to see if that will help me tune it. Then I stumbled upon Dial A Jet and was wondering if anyone has tried similar products? Sounds gimmicky to me but am looking for input. http://www.thunderproducts.com/dial_a_jet.htm

 

[xjwmx]

It looks like it dribbles gas into the intake bell. Maybe you wouldn't be able to tell a difference with that either

In case you are a visual type person, there's a test spark plug available with a clear insulator that lets you see into your combustion chamber. You adjust your mix until the yellow flame turns into mostly blue flame. Not sure anymore what it's called but you can find it. Somebody had one for sale a year or so ago in the classifieds. Probably still has it.

 

[5twins]

That would be the "Color Tune". A bit of a gimmick that came around about 20 years ago. Pretty much came and went. I'm not saying it couldn't be of help to someone who really knew what they were doing but for you, probably wouldn't help much.

With today's gas, plugs don't color up like they used to and it can take quite a few miles, like 50 to 100, before you see any coloring. So, plug reading isn't as good of a tuning aid as it once was. Your "one quick run, throttle chop, plug read" probably isn't going to show much. The plugs will still look new with no color and that could lead you to believing you're running lean - which you may not be.

I find better tuning indicators to be how the bike runs and performs. Are there any flat spots or hesitations, or areas of break-up and stumbling, throughout the RPM range? Does it transition smoothly from idle to midrange and from there to the main circuit? These CV carbs are very forgiving and will mask over improper jetting to a certain extent unless you push them hard. To test your jetting, you'll want to use big handfuls of throttle, even absolute full throttle at times (upper midrange to main transition test). If you just putt around and feed it throttle gently, it'll run with about any jets you put in there.

 

[xjwmx]

^He said already he can't feel any difference. You shouldn't diss the Color Tune to him in preference to your own....preference. Or get him by the collar and shake him.

 

[grizld1]

I bought a Morgan Color Tune plug some years back and gave it away--wouldn't take money for something I found to have no value. The problem with the device is that it can't be read at wider throttle openings--all you can do is look at the mix at idle and momentary transitions, no steady state readings are possible at wider throttle openings unless you want to grenade your motor. Of course you could run the bike on a roller brake, but building/buying one would pay for a lot of dyno tuning sessions. Re. the Thunder Products Dial-A-Jet, don't waste your money.

 

[scabber]

Like 5twins said if you cant tune what you have. I have been doing some jetting since changing exhaust systems. I'm getting really good at pulling my carbs. I have been limited with two jet sizes A 137.5 and a 140. I have the XS john needles more choices. It is pretty much like the carb guide says. I tried the 140 and dropped the needle 1 clip up. Test drive main jet too big 5000 RPM stumble. Back to the 137.5 and another clip change raised the needle back up. My base line setting with the 137.5 was with the needle raised richer. Another test drive Success Bike running strong from idle to redline. I need to do some minor tuning idle circuit mixture screw adjust. And check the sync. My advice what ever you have connected to the back of your carbs for the KN filter toss. If you have found no difference with jet changes. Make sure your ignition timing is correct to begin with. The dial a jet is for the big inch Harleys. You know the loud pipes bigger jet. black plugs can't tune my way out of a paper bag crowd.

 

[grizld1]

Actually the Dial-A-Jet was developed for 2-stroke snowmobiles by a snowmobile vendor (Thunder Products). The only question in my mind is whether it would make a small mess or a big one in a 4-stroke carburetor; things would have to be pretty screwed up to begin with for it to make a positive difference. It's just an aftermarket version of the "power valve" fitted to some 2-stroke performance carbs, particularly marine versions.

 

[TwoManyXS1Bs]

This dial-a-jet won't instantly fix your problem, in fact, it adds another level of complexity.
Properly tuned carbs work fine, you're still in the tuning zone, keep at it.

My real problem with this product is the accompanying infomercial, reminds me of all those miraculous 'jc whitney' gadgets...

 

[hotrdd]

I actually considered buying a set of wide band Air/Fuel gauges and the dial-a-jet just to see if the thing would do what it says it’s supposed to. Right now my biggest problem is just the time to play with the bike. I have a new property with a HUGE shop but since we just moved in there are too many other things that need to be looked after first. I was hoping that buying the Air/Fuel gauges or dial-a-jet would give me the future flexibility to change things if I wanted without having to pay someone to re-jet it again. Since I haven’t had any luck jetting the bike myself I’m distend to pay someone else to jet it until I can figure this out for myself.

I think we need to start “borrow a mentor” that will just come to our shop and help 

 

[hotrdd]

Forgot to mention the bike seems to run okay, just not great. There is some stumbling in the mid-range, however if I crank the throttle it seems to take off and is fine. Which is nerve racking when I am rounding the corner trying to merge onto the highway.

 

[hotrdd]

So after talking to a few different local shops they are all telling me around $500 to get the bike jetted. So I thought I’d try a few more things myself first. Since I have a custom intake I ordered in some “honey comb” air straighteners that I am going to insert into the intake and then I am going to order a Wide Band O2 sensor that I can use to dial in the different ranges. I’ll keep you posted.

 

[hardrock785]

dont know if it will help but look into your carb slide cut out angle.

 

[Scrambled]

I would ditch the funky K&N set up and get some unis, no matter what your bike will be easier to tune . Have you done a compression test ? (* see Evermores thread ). How about your ignition ? Ignition problems get mistaken for carb problems all the time . Your exhaust might be the problem, some systems are almost impossible to tune . Go over the basics again , you probably missed something simple . Happens to everyone once in a while .

 

[hotrdd]

Yah I think if I am going to go over everything again I should consider putting on new carb boots to rule them out. Is there a way to test the Carb boots? Mine look fine and seem to be flexable. I have a set of Uni filters I can throw onto the bike as well and see if that makes any difference.

 

[westonboege]

I dont have much to add to what people have said... but...

I just built a few 1into2 intake manifolds for one of my xs's, and am running a mikuni 36 roundslide with it. It is so simple its awesome.. No more synching, no worrying about old cracked rubber intake boots... It has made the bike run way smoother and more fun to ride/work on...

Not sure if there has been performance loss or gain. I think you will always get the best performance out of dual carbs... but the bike i run it on isnt a race bike... just a cruiser.

I also tend to try and read my plugs, but ive found that it can be misleading too... Really cant argue with seat of the pants and smoothness... I just want to bike to be safe... ie i dont want to burn any holes in pistons on the freeway...

 

[hotrdd]

westonboege - Do you have some pictures of the 1 into 2 ? Also any idea if the BS38 is BIG enough to fee both sides>

Finally if I go get new boots are the MikeXS Carb boots any good?

 

[westonboege]

Here you go.... I dont have any experience running the 1-2 with a CV carb... I usually ditch the stock carbs as fast as i can... every set I get needs butterfly shaft seals... boots... rebuild kits... and jets...

I just pay for avoiding headaches i guess..

This is the bike im running them on now... this pic was before the 1-2 was put on tho...

 

[coughing skunk]

Not to go OT, but westonboege how do you ride with those bars??

 

[Scrambled]

Not to go OT, but westonboege how do you ride with those bars??

I asked him that 1st time I saw them . We need a pic of him riding that bike !

The 1 into 2 ,if done properly , would be way easier to maintain and as far as performance ,you would lose some top speed but gain bottom end grunt . Some old Triumphs I had were single carb, and they worked very well .

 

[Scrambled]

If your boots look good they probably are . The stock boots are much better than the aftermarket.