Something to think about,,, when you are measuring vacuum on an engine that is runing you are measuing the Manifold vacuum, after the throttle plate,slide, whatever. when you open the throttle you will drop vacuum because of the slide opening and allowing air to equalize the pressure on both sides. The air pump (motor) is now pulling air with no restriction othe than the size of the venturi of the carb. Therefore you will not have a vacuum until the pump overruns the venturi. Remember we are talking about the manifold side. This is why the main jet is in the middle of the venturi. The Dial a jet apears to me to work by coming into play when vacuum from the motor overruns atmospheric pressure. you would need to put your vacuum guage outside the venturi (airbox side) to see it........ I THINK.....i'm no expert but i think i get it,,, now i think i need to get one.

 

Actually at this point, I just don't care to push anything other than the fact that I am the only one so far that has actually used the actual Dial-A-Jet and can speak from experience. That experience is from 12 years experience/45,000 miles/multiple modifications on one bike and also running them in an in-line 4. Then there are the several riders who have successfully run them after taking my recommendation. One on an XT225 and the others on KLX650s.

That makes all else pretty much opinion without experience.

 

Unless you have experience on a KLX250, then you only have an opinion without experience on how it would work with our bike. This is a KLX250 forum isn't it?

Looks like nobody has experience with a DAJ on a KLX250 yet.

 

Well, why don't you be the pioneer here and find out?

I don't know, HB...you almost sound like you're on a campaign against the DAJ. I don't have stock in the company and probably won't get one, but the principle here isn't black magic, and the device has been around a long time. The fact that it has worked very well with watercooled 4-stroke singles like ours and many other types and designs of engines seems pretty solid. Just because we can't get a response on a specific KLX250 here probably doesn't mean a lot. In fact as more and more bikes have gone to FI, we'll probably hear less and less.

 

For me I live in Indiana, we have hills but no mountains, I'm not likely to change more than 1500 ft. in elevation any where I ride. The dynojet kit was $50 and worked perfect with fairly easy install, 2 hours start to finish. The dial a jet cost 3 times as much and offers me no benifit at all where I ride so the decision for me was easy.

 

Wow! My math must suck... $79.95 = 3 X $50 I'd have never thought that. Good thing I don't teach math.

 

Whatever dude the price i saw was $159 and tax, but i don't really care as I know how to work on a carb.

 

Nice thread. Love to hear the experiences and ideas.

I seen one used on a CV HD with good success according to the owner. Before the CV, I can see the benefits of this.

All of my CV experiences on the multi cyl rides worked ok at elevations but not precise as mentioned above. CV's work using atmospheric pressures. I liked this explaination http://www.ch250.net/techtips/19.htm

I still had to use temperature, humidity and barometric recordings in order dial in the ride to fine tune performance and refer to my logs. Then do it again 2 hrs later to verify settings. (I have a stack of mains in the tool box)

I can only think that it would be a nice concept on the KLX if you play from sea level to 5000 ft every few days for joy riding. And of course, joy riding is what the KLX is all about. Is it worth the extra cash outlay? Stay with what you like and what works for you. Unfortunately, I do not have a KLX to play with at the moment.

 

You've got to buy the "snorkel" attachment also for our off-road machines which adds cost. Plus shipping.

 

I asked Thunder Products if they would give me a Dial A Jet to evaluate for my 351 09 KLX. If they do I'll keep you posted.