Dial-A-Jet

[troybilt]

Anybody ever tried one of these contraptions? I know they've been around for years but I haven't much or read much about them. I'll try searching more... just curious:

http://www.thunderproducts.com/dial_a_jet.htm

Found some more information:

http://www.mcmod.com/Dial_A_Jet.htm

[sixer3]

run a quick search in the 400ex forum, I remember reading some good info on it a long while back when I still owned my ex.

[troybilt]

Originally posted by sixer3
run a quick search in the 400ex forum, I remember reading some good info on it a long while back when I still owned my ex.

yea, just going thru that information now. What I was concerned about was with the 2 strokes. They claim to jet 3-4 jets leaner than normal when using it... only problem with this is risking detonation if it didn't work... IDK, I was hoping some of the 250r guru's might have some knowledge of this. You definitely don't want to run a 250r lean...

[sixer3]

yeah thats the big reason I never ran it. Maybe if I were to set it up on say an ex and noted how reliable it was then I'd feel comfortable setting it up on my R. Luckily enough for me personally I always ride at the same elevation :) and prefer to just rejet with mods

[86 Quad R]

those are great on high ended engines setup for duners, dirt drags and ect that frequent places with drastic elevation and/or temp changes.

[C41Xracer]

letron carbs come with something similar to the dial a jet, i have one on my 38 lectron and never saw a lean condition even at WOT 6th gear

[destey]

2 stroke snowmobiles have used dial-a-jet's for a long time. I've read mixed results.

Not a bad idea to measure EGT like some of the sled guys do

If you are looking for general jetting or tuning, “dial-a-jet” works good and is a decent tool, however; it is NO substitute for hands on precise tuning, specifically when it comes down to getting the best performance out of your engine while insuring your jetting is spot on…

Carlos.

[troybilt]

Originally posted by acecarlos
If you are looking for general jetting or tuning, “dial-a-jet” works good and is a decent tool, however; it is NO substitute for hands on precise tuning, specifically when it comes down to getting the best performance out of your engine while insuring your jetting is spot on…

Carlos.

That's just it without dyno tuning there is no way to get it spot on. You can get close but that's it, and then the jetting is only "spot" on for those particular conditions, temp, elevation, etc... I thought this might be a way to improve the OVERALL jetting so the bike is setup better thru the RPM range vs. having lean condition at WOT when its jetted to run better a low rpm, etc... kind of like porting, you can only jet perfectly for a narrow range of rpm, but its pretty close overall...

just a thought... I hadn't heard much about the dial-a-jets on the 2 stroke side of things... mainly 250r's in general...

What I was trying to say is based on my experience and those around me that have used “dial-a-jet” in the past is; you can only get close with systems like “dial-a-jet”, however; you can get a lot closer by tuning by ear and seat of the pants feel…

Yes the rear wheel dyno is a great tool for tunning, porting, flow bench work, and testing all pipes, carbs, intakes, jetting, ect…

However; it is no substitute for the final tuning phase, and the final tweaking must come from seat of the pants feel and ear tuning & jetting.

Carlos.