Eric Gorr


246 replies to this topic
  • cwtoyota

Posted 11 March 2012 - 08:01 PM


I installed a different spring in mine also.



Can you elaborate on this a bit?
Is that on your current YZ295 or something Suzuki specific?

Are you guys changing the spring in the top end? Or the coil spring in the PV governor next to the water pump?

Who makes it the springs and/or where did you buy them?

How did it effect or improve power and delivery?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • motolink

Posted 12 March 2012 - 01:28 AM


I am Refering to the tension spring on the top that controls who quickly the exhaust valve opens, I found if I left the same tension on the spring as a 250 the valve would not open quickly enough therefore poor power. The tension had to backed off quite a bit to allow the exhaust valve to open early and raise the exhaust port because the 295 does not REV like a like a 250.
It made a difference to the power delivery.

  • BRM

Posted 12 March 2012 - 02:27 PM


I'm running a softer spring on the govenor, (by the water pump) for the same reasons mentioned above.
I have some photos that I have been meaning to post up.
Can't comment on the difference as I installed mine with the build.

  • shagger

Posted 12 March 2012 - 03:10 PM


I noticed while ice racing, a very power hungry activity, that I would like to have the last two little guys on the sides, the ones that open last, open sooner. The engine responded to their opening in such a way as to suggest that an earlier opening would provide a broader band of near maximum power.

(YZ295 Mobetta + race gas head)

  • secret shed

Posted 12 March 2012 - 04:46 PM


i just recieved my eric gore yz295 mo-betta, race gas set up, very happy with the turnaround time, less that three weeks, the cylinder looks like brand new, the piston is a sweet looking coated wiseco, and everything else is there needed to reassemble the top end.
the only thing missing is how this beast should be jetted...
i have a FMF gnarly, with a powercore silencer
stealy flywheel weight
also i`m in minnesota, and will be racing D23 mx
hoping with this information someone out there can tell me how to jet and tune this, i haven`t been on a 2-stroke in 12yrs, and i am trying to build this to beat my yz450 (and everyone elses 450 too)
i`ll get some pics up as soon as i can figure out how, lol

  • clearedforlanding

Posted 13 March 2012 - 09:08 AM


hey guys, i just got my 265cc mobetta+race gas set up back from eric as wel land i am curious if anyone has any good starting points for jetting this yz. kind of feel like the only thing that i got left in the dark with on this was no suggestions or anyth ing on jetting when i got it back. thanks for the help

  • primerib108

Posted 13 March 2012 - 12:32 PM


Hard to get a decent bead on jetting in regards to the eric gorr kit (I have the same one)......I think the saying goes every bike is different and the whole altitude/temperature plays into effect as well. I asked a good friend who is an old yz rider what he found worked well and went slightly fatter just for the break-in process.

  • BRM

Posted 13 March 2012 - 02:14 PM


i just recieved my eric gore yz295 mo-betta, race gas set up, very happy with the turnaround time, less that three weeks, the cylinder looks like brand new, the piston is a sweet looking coated wiseco, and everything else is there needed to reassemble the top end.
the only thing missing is how this beast should be jetted...
i have a FMF gnarly, with a powercore silencer
stealy flywheel weight
also i`m in minnesota, and will be racing D23 mx
hoping with this information someone out there can tell me how to jet and tune this, i haven`t been on a 2-stroke in 12yrs, and i am trying to build this to beat my yz450 (and everyone elses 450 too)
i`ll get some pics up as soon as i can figure out how, lol


As a starting point, Main 175-178, Pilot 45, needle clip 2-3.
There is no way you will beat a 450 running a gnarly pipe, they take too much away from the top end which is where the 450s will eat you up.

Edited by BRM, 13 March 2012 - 02:16 PM.


  • BRM

Posted 13 March 2012 - 02:20 PM


I noticed while ice racing, a very power hungry activity, that I would like to have the last two little guys on the sides, the ones that open last, open sooner. The engine responded to their opening in such a way as to suggest that an earlier opening would provide a broader band of near maximum power.

(YZ295 Mobetta + race gas head)


exactly what this little fellar on the right does

Posted Image

I have also opened up the breather outlet to reduce back pressure behind the side power valve.
If you have room on the exhaust side you can do both. This will help it rev.

Edited by BRM, 13 March 2012 - 02:21 PM.


  • FRECNDY

Posted 13 March 2012 - 07:31 PM


hey guys, i just got my 265cc mobetta+race gas set up back from eric as wel land i am curious if anyone has any good starting points for jetting this yz. kind of feel like the only thing that i got left in the dark with on this was no suggestions or anyth ing on jetting when i got it back. thanks for the help


I'm thinking about this setup as well. Post up how you like it. Might do low-mid, though. I have WR gears that will go in at the same time, and I like stupid singletrack climbs.

  • cwtoyota

Posted 14 March 2012 - 09:43 AM


exactly what this little fellar on the right does


More coils = softer = opens sooner, makes sense to me. Where did you buy it?

Thanks for the extra info guys!

  • kenpowell

Posted 14 March 2012 - 11:48 AM


Jetting for 2003 YZ265-WR (2008 YZ250F forks) with Eric Gorr low-to-mid porting: at 60 degrees:
PJ - 48 - still feels a little lean
Neddle - N3EJ / 2 - Still feels a little rich
Main - 172 - still feels a little rich
Timing - .007"

Very little spoog though; runs great.

  • BRM

Posted 14 March 2012 - 02:11 PM


More coils = softer = opens sooner, makes sense to me. Where did you buy it?

Thanks for the extra info guys!


http://ciscos.com.au/

Speak to Steve.

  • secret shed

Posted 14 March 2012 - 04:13 PM


hey BRM, you sound pretty knowledgable about these yz295`s,
what kind of pipe silencer combo do you think works best for these? i was told that the gnarly/powercore2 combo was good for these 295`s, because they aren`t a top end motor, and it is the (mo-betta) better overall, race gas porting.
i see these lighter springs for power valves, are these also needed? where can i get them?
opening up breathers? opening them up where?
is there a special break in procedure for these, due to the race gas and coated cylinder/piston? so many questions, sorry! i`ve been on 4-strokes too long.
any suggestions are greatly appreciated

  • blueripps

Posted 14 March 2012 - 04:30 PM


More coils = softer = opens sooner, makes sense to me. Where did you buy it?

Thanks for the extra info guys!


I could be out of line here, as its probably a proven spring for the YZ250 power valve. But JUST incase this is experimental, this info could help dial in the right spring.

My 2001 YZ125 from factory came with a spring rate that was to soft, causing a bog when cracking the throttle. Power valves opened to soon. Went to an earlier model heavier spring, and made it just right. So, if after installing this spring you notice a slight initial bog that you didn't have before, try the next step heavier.

  • cwtoyota

Posted 14 March 2012 - 08:26 PM


[color="#0f72da"]http://ciscos.com.au/[/color]

Speak to Steve.


Thanks BRM.

Blueripps, That makes perfect sense to me.

  • joshua_inigo

Posted 15 March 2012 - 05:57 AM


i think when it comes to "MO-BETTA", this technology is way betta hehe :thumbsup:

Lightweight DI 2-stroke by Athena


  • Budlite

Posted 15 March 2012 - 06:33 AM


something else that is interesting in the Athena site......a 72mm cylinder kit for the YZ250
[color="#0000ff"]http://www.athenaparts.com/eng/kits/view/19470/cylinder-kit-o-72[/color]

  • cwtoyota

Posted 15 March 2012 - 07:01 AM


something else that is interesting in the Athena site......a 72mm cylinder kit for the YZ250
[color=#0000FF]http://www.athenaparts.com/eng/kits/view/19470/cylinder-kit-o-72[/color]



Interesting indeed.

  • joshua_inigo

Posted 15 March 2012 - 07:48 AM


something else that is interesting in the Athena site......a 72mm cylinder kit for the YZ250
[color=#0000ff]http://www.athenaparts.com/eng/kits/view/19470/cylinder-kit-o-72[/color]


Am i getting this right Budlite? :thumbsup:

This YZ250 Athena kit is actually a 300cc bore x stroke at a high 16 : 1 compression ratio?
http://www.athenapar...00485100042.pdf





Related Content

Forums
Photo

YZ250 Future? by Haulinass Kiwi


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • Hot  97 replies
Forums
Photo

1995 rm80 by rohan1234


Dirt Bike   Make / Model Specific   Suzuki   Suzuki 2-Stroke
  • 0 replies
Forums
Photo

2003 Yamaha YZ250 2 Stroke Diagnosis Help! by BrandonTMeharg


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 2 replies
Forums
Photo

Another YZ250 Start Axel Shaft Break! by Evilkinevil


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • Hot  40 replies
Forums
Photo

1998 YZ125 restore Pictorial by THEKX250F2007


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 3 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

Register Close
If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.