18 sx150 Dyno tuning part 2 , keihin carb and stic tests

[HERA]

1 hour ago, Muffintop said:

How does the engine keep revving if it's only 1/4 throttle? Wouldn't it just be a flat line.

 

Also if you use a trusty NECJ needle it probably would have been at least 45hp

YES!!  Easily provable in your neighborhood or anywhere else for that matter.  Even on the kickstand, you can show this..  Thanks 

[mog]

You can see by the numbers this is full throttle and its a necw needle btw

 

[emoji16]

1/4 is only 30hp , probably could get more with work but it's already above a Cr 500

 

For those interested the mikuni on every bike won't make decent 1/4 throttle power , if you want more real world ( track not Dyno ) power replace your mikuni with a keihin ,no other mods and you will feel and instant improvement ,it's more noticeable that a head or pipe or vf4

 

To recap

 

Vf4 if you think you will gain hp you will be disappointed

 

Head again zero proof of gains ( in fact it lost power at 11k with tighter squish)

 

Pipe FMF factory fatty solid gains

 

For me the pc 304 silencer works with the stic well

 

Keihin carb , slight increase in torque ,slight drop at peak hp ( part throttle different world )

 

Stic just boosts power from the instant you turn the throttle , never a loss anywhere ( on a 2 stroke - unheard of )

 

You look for dynos of heads , you will see lots give you more front side ( which is where you want it ) but they do give up peak and overrev , it's just a fact ,if you love to rev a higher comp head is making your engine worse

 

The stic adds power to the front side and peak and over peak ,best mod you can buy for a 2 stroke by a mile ,I've been buying aftermarket parts for over 30 years and it's the game changer

 

I was impressed with the get ignition on a sxf 250 , it added hp everywhere

 

 

 

 

[Braaaper121]

Lol if you have a brain , George said hes seen a 125 rev to 14500 , and I know this 150 revs crazy high ,so I said to Dyno guy just hold it on and see , he wasn't happy at all ! I found it amusing to listen to ,even with ear defenders it sounded loud and painful

My honda cr 125/139 has the STIC. Revs to 14,400

[mog]

Just an update , ran the 150 yesterday with the adjusted PV and slightly richer main jet (colder here now) I can't tell you how impressed and fun the 150 is ,the PV changes the power considerably ,from 6k to 9.5k with no losses !

It pulled super hard and so crisp , the track was hilly and even against fast riders on 450s I never once felt them pull me ( other than they were faster than me ) plenty of 450 riders I passed , my friend said how his sx250 actually found it hard to stay with me out of corners ,he could only gain on the longest uphills toward the end of the hill ,oddly he could catch me downhill , I need to work on that as it should not happen ,I used some 672 renthals and felt I was cornering better than ever with those .

Just simply the best most fun ,crazy sounding bike ever.

To give you an idea how fast it is , in 4th gear uphill it would pick the wheel up towards the end if the gear ! I had to often back off to get into the next corner !!

[19Moto]

Can you share your settings as they stand right now.  Pilot, Main, air screw, needle type and clip location, PV setting, fuel type and pre-mix ratio.  

[mog]

Sure

42 pilot
As 3
Slide 6.5
Necw needle and richest clip
190 main
Cool temperature 65
114 stic
97 ( euro) super non ethanol fuel
30:1 ratio
PV is 2.5 from fully out

But it's important to set the PV each time you make a decent chance to compression , port timing etc ,and that can affect the jetting as well

I think a Dyno tune is invaluable honestly ,you can see the changes to power and fueling , and it takes seconds ,once dialed in you can make the normal changes for temperature etc

[Pesh Merga]

What happened to needing a big pilot for the STIC? 

[mog]

We started with 55 ,but with that needle it didn't work ,it was perfect fueling on full throttle ,but on half it was mega lean ,so richening the needle then made the main change ,that made the pilot change

 

The stic is different how the main and pilot interact

 

 

[Pesh Merga]

George says the N3EJ is the needle to use, did you ever use that? 

 

On a side note, any fitment issues with the Keihin into the VF4R? Not crazy about the way it sits..

[mog]

No I tried the 150 sx needle and it worked decent( similar I believe to the yz needle) but then I would have to pay for the Dyno time to tune every circuit , the initial runs( full power ) showed good afr and the same power curve as the necw needle, so I didnt persue it , I already had the settings for the necw from the last Dyno session

 

It would be great to try different jetting

 

So far I have tried

115 stic

114 stic

Noz needle

Necw needle

7 slide

6.5 slide

Many many pilots and mains

 

The most hp came from the 7 slide( borrowed) 115 stic , scravini silencer , but it had no get up and go ,it was a long endless power ,now it's instant , responsive ,fast ,but it doesn't reward hanging onto gears like before ,( which you had to )

 

 

 

I don't like the fitment of the keihin into the 18 boot but I have lived with it so far ,the 16 boot would be nicer but I'm just not so ocd as to buy one ,I can see why others would ,the STD boot works fine in reality

[Pesh Merga]

Appreciate the info and time you have put into this. I should mention also that I am sporting the 38/40 taper bore. 

I do like the 24/30:1 zone, race gas, etc. For now the stock pipe/silencer, at 15-1600 meters elevation too. 

 

Are you still running the thin base gasket?

 

EDIT- it is a 19 TC125, not sure how much that really changes things? 

 

Red PV spring 1 75 turns in from flush

6.5 slide

N3EJ 3rd 

52 pilot 

3 turns out 

Klotz Super Techniplate 30:1

110 race gas

Edited October 1, 2018 by Pesh Merga

[mog]

No I went away from the thin base gasket ,the gains were small ( but I have to admit the highest peak was with 0.4 base gasket ) im back to just thicker than STD now ( Dyno says less hp ,feels like more to me ,my Dyno guy is having tons of problems with his 250i and dynojet are not very helpful )

 

Dyno says I have less peak and front side ,but it feels better from the crack of the throttle to peak ,then it gives up faster than before

 

The taper bore will require slightly different jetting as does the 150 ,they use different needles to the 125

 

 

[mog]

The factory fatty is a great pipe but on the 125 so is hgs

Hgs on 150 was terrible

The 19 doesn't have many pipes I believe as yet ? On the Dyno the husky beats the KTM by 0.5 hp due to the airbox

On the 4 stroke it's reversed

[Pesh Merga]

Only pipe I have seen yet is the FMF... would love to see other offerings, fan of HGS. I wouldn't mind another Euro pipe too. 

[mog]

Hgs released the 19 pipe the other day

[Pesh Merga]

THANKS! I will ring Buds and go with it.

[19Moto]

Modified the jetting on my 2016 150 with 0.114 STIC.  

Started at 190 main and 52 pilot.  Seemed fat on top.  Dropped to 185 Main and kept the 52 pilot.  This was pretty good but I felt it could be better.  I put about 6 hours on bike between those 2 conditions.  Just changed to a 188 Main and 50 pilot, keeping everything else the same.  This small change really seemed to make everything crisp.  I could even tell a difference when blipping the throttle while in neutral.  Assuming the temp stays consistent I can't wait to try this combo on the track.  

[mog]

Notice the rider comments ,pipe bang gone
Changes in elevation no jetting required
Way more power ( we know that part )
Emissions below the tpi bike , shame KTM added all those parts instead of one small one

[19Moto]

Is there a reason many of the larger Motocross Mags have not reviewed the STIC?

[mog]

Yes he has not made it available for testing as the patent process is just being finalised

Once that is done he is interested in magazines testing it