ESE's works engine tuner

[TZ350]

Omg, I did it, engmod on it's way (big deal for me, money I haven't got to spare but f*ck it )

Next hurdle to get a working rz pack together but that's part of the charme I guess.

Chuffed

Money well spent in my opinion ...... the forum idea sounds good too.

[TZ350]

Thomas is holding the NSR250 frame and swingarm I got from Husaburg, 14kg all up, for those that like to know these things.

[F5 Dave]

Just if anyone gets interested here is a YPVS mod file taken from the TZR forum which seems to be missing now. I just grabbed a few pertinent pages with the instructions & some text. not edited but should give you everything.

[husaberg]

Just if anyone gets interested here is a YPVS mod file taken from the TZR forum which seems to be missing now. I just grabbed a few pertinent pages with the instructions & some text. not edited but should give you everything.

Yow (MIKE) should be able to follow that up i have some stuff somewhere but i guess he is better organised than me.

Thomas is holding the NSR250 frame and swingarm I got from Husaburg, 14kg all up, for those that like to know these things.

See how easy this frame would be to shortened and narrowed it's practically begging for a NX4 rejigging.
You have the technology and the facilities. You have access to a NX4 frame as well too.
Skill saw (with blade reversed) works great on alloy plate but sounds like a mother-in law though.

1997 Honda RS125 Specifications
Item Specification
Dimensions Overall length 1,800 mm (70.9 in)
Overall width 570 mm (22.4 in)
Overall height 985 mm (38.8 in)
Wheelbase 1,215 mm (47.8 in)
Ground clearance 110 mm (4.3 in)
Seat height 700 mm (27.6 in)
Half dry weight 71 kg (156 lbs)
Fuel capacity 13.0 liter (3.4 US gal)
Caster angle 23 ° 30'
Trail length 84mm (3.3 in)


NSR MC16
Length: 2035mm
Width: 705mm
Height: 1105mm
Wheelbase 1360mm
Seat Height: 750mm
Ground Clearance: 135mm
Weight: 125Kg
Fuel Tank: 16 litre (primary)1.2 litre (reserve)
Castor: 26° chopper like
Trail: 103mm as above

OH yeah through in a MC22 gullarm as well Doohanrific mmmmm....That Suzuki engine may have to go.............

[Yow Ling]

Yow (MIKE) should be able to follow that up i have some stuff somewhere but i guess he is better organised than me.

.............

Yea Right, I use the internet to store important stuff, and cant usually find it back

[TZ350]

Giggles and Kel have been giving me a hand setting the bike up for the weekend.



By leaning the main jet out I could get 31hp (Red Line) but then the mid range became lean and drive suffered. Fitting a larger main jet (Blue Line) I got better low end drive. I experimented with shutting the power jet but that made it worse every where so I expect the problem is in the air correction jet and hope that by drilling out the air correction jet I will get most of the top end back.



I will have to progressively drill the air correction jet out to see.

The theory is, as the air velocity through the carb increases, the fuel/air ratio gets richer. The air correction jet feeds air to the needle jet holder and is supposed to correct this enriching affect. To small an air correction jet and the top end goes rich, to big and the top leans out.

Maybe the air correction jet has to be right before the power jet can do its thing properly.



There is a lot more info on carb tuning on Husa's original post.

Random order though sorry, but if you can read the text i am sure the numbers at the bottom so they will give a clue to the order

Power jet or air correction jet?? more experiments tonight.

[RAW]

I was wondering about setting up the powderjet jetting. I have the Kehin solenoid powderjet modded the way you showed on this thread and the .35 jet recommented but because of other issues with my bucket I blocked it off with a soldered up jet and tuned it up as a nomal carb. Now say I used a 1.60 main jet on the nomal carb then I add the powderjet is it 1.60 main jet minus .35 powderjet = 1.25 main jet is that right?

With regards to the power jet modification, by this do you mean altering the size of the jet or is there some other form of modification I hav missed ?

[Grumph]

Thomas is holding the NSR250 frame and swingarm I got from Husaburg, 14kg all up, for those that like to know these things.

Shit, that's heavy. Out with the holesaws.....

[wobbly]

The powerjet dump tube on the KX carb is down very low in the venturi,I have been bending this upwards toward the carb centreline.
This is due to the MX bike using the solenoid switching at very low rpm.
In a race situation you dont need vacuum on the jet down low and up higher is where the dump tube is on the SPJ carb from Honda RS125/250.

[TZ350]

A few new bits for my next project.



For the Beast.

Suzuki GP125 flywheels bored for a bigger B/E RGV250 pin, balance holes plugged, Malory metal slugs for balancing, inside faces skimmed back for more rod clearance and crank case volume.



And for the F5 class, a 43mm piston and de stroked RG50 crank gives 49.8cc.

[husaberg]

Giggles and Kel have been giving me a hand setting the bike up for the weekend.



By leaning the main jet out I could get 31hp (Red Line) but then the mid range became lean and drive suffered. Fitting a larger main jet (Blue Line) I got better low end drive. I experimented with shutting the power jet but that made it worse every where so I expect the problem is in the air correction jet and hope that by drilling out the air correction jet I will get most of the top end back.



I will have to progressively drill the air correction jet out to see.

The theory is, as the air velocity through the carb increases, the fuel/air ratio gets richer. The air correction jet feeds air to the needle jet holder and is supposed to correct this enriching affect. To small an air correction jet and the top end goes rich, to big and the top leans out.

Maybe the air correction jet has to be right before the power jet can do its thing properly.



There is a lot more info on carb tuning on Husa's original post.



Power jet or air correction jet?? more experiments tonight.

As i am lazy what is your Needle jet and a pic please.

[TZ350]

As i am lazy what is your Needle jet and a pic please.

OKO Needle Jet .....

[bucketracer]

As I understand it, Mikunis have different sized needle jets and one base diameter for the needles. On the other hand Keihen style carbs have one size for the needle jet but different base diameters on the needles.

[wobbly]

I think you are going to get lost - running a 4T bleed type emulsion tube and trying to tune that, assuming its a primary correction system is asking for trouble.
My take is that ALL modern 2Ts have primary emulsion correction only, wherein all the correction air bleed is fed into the well around the shroud.
It must be obvious that its well proven that is all that is needed to get a perfect fuel curve.
Having a 4T type air bleed emulsion tube, with a series of holes is just a confusing tangent you simply dont need - and very few understand.
Weber and Dellorto have hundreds of variations, you have one tube - and you have no idea what it is doing, nor where or why , in the powerband.
Your call, but seems you'r asking for brain damage to me.

The Japs are sticklers for corporate integrity - yes Mikuni have variable tube diameters,and only change the needle angles, and taper start point.
Keihin on the other hand have a single tube diameter - usually a machined hole in the casting, and vary the parallel diameter of the needle range, plus the taper start point.
No advantage to either - apart from being not being the same - not allowed,in the Land of the Radioactive Sun.

[ief]

What would of been the use of using them bleed types anyway? Lot of stock bikes have them, emission stuff?