I have an eme micro ive built for freestyle use, whats the easiest way to tune for best main jet and high speed screw settings? I know a tach is ideal....I have a tach but im not sure I can tap this thing out without wrecking, the hull seems soo small and is super fun to ride so far but pretty nuts at high speed, im guessing some method of testing best acceleration maybe?? but looking for tips from guys who have done this, thanks
How to tune MainJet/high speed screw on freestyle ski
- Thread starter maxboost
- Start date
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
What engine/mods/carbs? You can try strapping it to a trailer otherwise get it up on plane. Check plugs with a hack-saw.
760 4 mil stroker, heavy freestyle porting in cases and cylinders, v2 pipe, oem 46 mm mikunis, v force 3 reeds with php intake, zeeltronic, I think a shallower prop would help me out for I’m not cavitating at all, currently running 11/17 hooker in a oem 140mm kawi pump
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
And whats your jetting now
Quinc
Buy a Superjet
- Location
- California
I am running similar setup minus the 4mil with 120M 135P 24psi pop off and it is perfect at exactly 1 turn out on each screw. You might try this with 1.75 turns out then work your way back in and see if it gets better.
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
^4mil is quite a different beast though.
Maxboost - How does it run? Any hesitations, load-ups, or cut-offs?
Maxboost - How does it run? Any hesitations, load-ups, or cut-offs?
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
http://www.x-h2o.com/index.php?threads/tuning-tips-for-rookies.39846/
With that hull, your not going to tune using the MAX RPM method as well. This is going to be a more "Seat of the pants" type tuning.
With that hull, your not going to tune using the MAX RPM method as well. This is going to be a more "Seat of the pants" type tuning.
It’s runs pretty well, the pipe really comes on hard about 1/4 throttle and from there on straight screaming, gotta pull the timing back from around 4000 rpm on and she really comes to life.
I always kinda wonder what people mean when they say stuff like that. Why is 1/4 throttle being mentioned in a conversation about high speed jet? Why does anybody care how much power is made at 1/4 throttle, if you want more power why are you not using full throttle?
I built it, bought the cylinders from @SmittySX so maybe he can elaborate but doesn’t matter I’m not looking for exact jetting, was just looking for some friendly pointers, thanks
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
Well, you want to be sure your plug looks like a phillipino or darker. If the engine revs out clean, wack wot 6-7 times and verify the engine does not have any stumbles.
Here’s my tuning advice. Read this page over 3 times. Bring a hacksaw to your tuning session.
https://www.crankshaftcoalition.com/wiki/Reading_spark_plugs
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Here’s my tuning advice. Read this page over 3 times. Bring a hacksaw to your tuning session.
https://www.crankshaftcoalition.com/wiki/Reading_spark_plugs
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Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
Here is a fresh plug with about 20 wot wacks and maybe 5 minutes of mid throttle. It’s perfect mid, slightly rich full.
For comparisons, here is another which has a decent idle circuit, decent main, but a mid range that’s about 5-10 points too lean
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For comparisons, here is another which has a decent idle circuit, decent main, but a mid range that’s about 5-10 points too lean
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@Zero Client thanks a bunch!! I really appreciate it, I’m anxious to cut some plugs up lol
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- Location
- Riverside, CA
Sorry this never goes over well, but judging engine tuning by plug color
is old fashion, totally obsolete, and a waste of time. If you live in California,
that has been a reality for a very long time.
These days (on 2-strokes) plug color is determined by running time, your
brand of pre-mix oil, and the oil ratio.
If you want to know how well your ski is jetted, learn how to tune it. There
are no shortcuts anymore with unleaded gasoline.
Bill M.
is old fashion, totally obsolete, and a waste of time. If you live in California,
that has been a reality for a very long time.
These days (on 2-strokes) plug color is determined by running time, your
brand of pre-mix oil, and the oil ratio.
If you want to know how well your ski is jetted, learn how to tune it. There
are no shortcuts anymore with unleaded gasoline.
Bill M.
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- Location
- Riverside, CA
OP, please correct me if Im not reading your post correctly. Your Running this motor in an EME Micro. You have a heavily ported 798cc stroked motor, on a V2 pipe with 46’s. More than likely, your end goal is flip tricks, as the Micro is a little small for hood tricks? You stated freestyle in the title, not freeride or race? Correct? To jet this correctly for freestyle, your going to need to feed the motor a relatively high volume of fuel off the bottom. (Reverse jetting as Quinc suggested is where I would start.) High compression, with a relatively high timing curve will be the key to get the hit your looking to achieve. The V2 will like to be run a bit warmer than a FR setup, so less water at the spray bar.
As Bill pointed out, Plug color has no relevance to this discussion. The motor will never be at high RPM long enough to color a plug. Plus also as he stated, the fuel / oil will not yield a good color. Chris suggested contacting your motor builder? Great place to start! The builder designed it for you, he should know where to start to get you in the ball park. There are many variables to properly tune this. Air volume into hull, pump loading motor, water routing, ignition timing, fuel delivery, exhaust temp/ back pressure, ect. Consider your boat unique, and recommended starting points are just that! A recommendation. Its easy to simply ask carb questions to get you going. Realize there is way more going on , that adds up to the big picture. First place to start, is the guy who built it and see what he recommends!
Ski ya, Paul
Zero Client
BeerrroooOOOT!!!
- Location
- Douglasville, GA
Yea don,
Baring WB, EGT, RPM, and hard to tell the seat of pants feel on his light ski, how else is the op going to dial in an ideal 12.3:1 AFR, when half a point or a quarter turn will throw off .5 AFR?
Ask the engine builder?
Or reference this chart on the day of tuning?
Yes, this works best w new plugs on a modest oil mix. After some minutes reads tend to vanish. Otherwise seems to me the op has very little to go by. I admit never tuned with crappy California gas being in the east coast where we can get ethanol free and high octane.
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