eric gore MOD 2005 to 2009 yz 144

[sam2007]

Just got my new yz 144 top end back from EG and jetted same .. perfect no stumble super smooth from IDLE to top only took one day to jet .. more easy to jet than the stock 125 cylinder .I choose more all over powerband ...this powerband and touque feels more like a 200cc super very happy with All ...winter jetting 2400 ft
38 to 60 temp pump gas ..PC pipe is the only other mod i have ... 4.5 slide ... 35 pilot 1 1/2 turns out .. 2006 to 2008 neddle 4th clip ...440 main

update winter jetting 40 pilot 2 out .. stock 2005 neddle 4th clip 4.5 slide 460 main .. much better low mid with this setup jetting about perfect now .. good luck to all

thanks again to eric gores forward motion racing

 

[hot125mod]

lucky I have been saying that I am going to have eric do my cylinder but never seem to get around to it hopefully sometime. your bike looks sweet I bet it rips just as hard no race fuel though, anyways sick ride dude

 

[sam2007]

eric did me a favor and set the compression on the high side so i mix about 25 % 110 sonoco with 91 pump to insure the motor works correctly .. it does rip works better than expected

 

[inotocracy]

Cool looking bike! Very clean.

 

[john stu]

eric did me a favor and set the compression on the high side so i mix about 25 % 110 sonoco with 91 pump to insure the motor works correctly .. it does rip works better than expected

if its on the high side you should be running straight race fuel....not mixed with pump

 

[dkgoodrich]

I'd love to get a 144 kit for my 00' yz 125 but I haven't because I'm afraid of blowing it up jetting it. I have no experience jetting a bike but I tune cars on a labtop at my speed shop. I just don't understand how you accurately tell the air fuel ratio... I use a wideband and pull plugs on cars.. and i used to use a temp gauge on my nitro rc cars now I just adj the low and high by throttle response and smoke content.

 

[sam2007]

just adjust and ride and adjust and ride .. start your jetting rich

 

[ericz103]

If your going to spend the money to get a 144 kit, its not much more $$ to have someone to jet it properly for you too. Or better yet find a friend/riding buddy and have him help you so you learn how to do it. I used to be into cars, and barely touched carbs before I rode, now at least I'm good enough to keep my bikes running good.

 

[dkgoodrich]

I've been reading and reading, looking at diagram and explanations after another.. I'm going to learn jetting the best I can before I step up to the 144 on my YZ. I don't see it being too difficult.. or much different than my rc cars, just more advanced. I'd rather scatter my stock stuff learning then carelessly destroy some expensive stuff w high expectations.

I have been looking at the athens 144 kit on ebay, how does it compare to Eric Gore's kit? What about pricing?

I have to do something to keep up with my ktm 125sx I built for my brother, it runs like a raped ape!

Thanks for your time,
dk

 

[SpDyKen]

Just getting the jetting right on your YZ will give you a much better spread of power, and you will be able to use that to out-ride your brother's KTM, even with the stock cylinder.

If you follow the advice of the various jetting threads here at this site, (and I cannot emphasize how important this is,)there is no way you will do any damage to your engine, as you will have learned what to be careful of & what to watch & listen for.

Double-check all of your mechanicals first, (reeds, comp., etc.) then check your float heigth. You'll start with your pilot circuit first, (and spend the most time on it,) and you cannot do any harm to your engine, if you make a mistake here. So, go wild, experiment, & learn.

By the time you start to work on your slide needle (needle jet,) you will have already gained a great deal of confidence. Always use the best fuel you can afford, and be consistent with it. You can always use some high-octane fuel when you experiment with your main jetting, to give you a safety margin, if you are worried.

It sounds like you have the aptitude, you just need the knowledge that comes from research and experience. Go for it & good luck! You're in for some very rewarding fun. :nod: :cool:

 

[SMMWest]

Eric Gorr has bored and ported 3 Cylinders for me over the years (I used to be sponsored by DGY and they farmed out all of their work to him).

I just got an old 1985 Honda CR125 and even though it is 24 years old, I am going to race it in the Lites class this year against brand new 250cc 4-strokes in the Intermediate Class. So in the next few weeks it will be sent off to Eric Gorr and Forward Motion to be "BIG BORED"!

Glad you like your bike. So it feels like a 200cc Engine huh? Can't wait to get mine done then.

 

[yzukko]

I installed also 144 EG (pumpgas,Enduro modded) to my YZ -06. like it plenty, but... Now have plenty problems with bottom power. I found middle and top jetting in position. Very
linear after 1/2 throttle. I' am quite impresssed about that!

From 1/16 to 1/4 found it very hard to jet linear. I have try 40-47.5 pilots. We have here very technical trails with ice and plenty of rock. I feel like i lost the traction after open the throttle little more than 1/8. Also it is getting very hard to drive on long sessions. It rips so hard from bottom! This bike suites now better to motocross, but enduro is very hard to my skills.

I have less than good jetting skills, but i think it is too rich all time when slide opens little. When no gear inserted, rpm jumps just easy to 4000 with only little touch to gas tube.

I have try to seek similar problem from everywhere internet, but this is first thread where somebody (sam2007) have modded slide from 4.0 to 4.5.

What do you think people? Can this rich standard slide be big part of my problem?

Bike info:
Temp 0 celcius, main 460, needle std 4, pilot 42.5
Gearing 14/49, pipe factory fatty, VFORCE3 reeds
pump gas modded e.gorr 144 enduro modded cylinder

 

[sam2007]

The slide mod i did is for where we race and ride here is california 80 to 110 temp ..1000 to 2500 ft from sea level ect... cutting the slide leans the mid speed/neddle and main jetting slightly also ...i have a 2005 yz125 carb on this bike and this has a richer neddle and one more carb bypass hole for richer jetting ..in 2006 yamaha changed the carb to one less bypass port and a leaner neddle for better low speed jetting ... so the 2006 may run fine with stock jetting ...check out pro circuit site they have a list of jetting specs for all bikes back to 1999 ...i have found pro circuit jetting to be helpfull

 

[sam2007]

yzukko i suggest one clip more rich on your neddle move the clip down one ..this lifts the neddle up and allows more fuel from the nozzle/ main .. neddle adjustment also slightly affects the low speed /pilot circuit

 

[yzukko]

Thanks for taking up this thread again !!

I see that you have totally diffirent conditions there than i have
here. I'll check the procircuit jetting info.

I ride the bike most at 0-1/4 throttle when riding enduro.
Now it works better in this area when the needle clip position is little lean (pos 3.5). Risk of detonation is there in middle area, but the power is smoother now on low rpm. I have learned to avoid the detonation, but it will eat my speed when racing

When i lower the clip from pos 3.5 to 4 have noticed following:

- 1/4 to full open very powerful powerband, no detonation risk. If i ride mx i would set the clip there.

- 1/8 to 1/4 is not there at all. Rpm jumps straight to 6000 or more.

- surely this 0.5 clip adjust will mess my pilot circuit.

- I have vision that this pos 4 is also best for enduro riding, but the 1/8 to 1/4 area is so hard to control that traction is lost almost.

Now I plan to try diffirent needle diameters. I'll try keep clip in pos 4 and same time try to lean 0-1/4 are with bigger diameter needle.

More ideas?