Are jetting changes needed after head mod?
- Grayhorse
- Member
- Posts: 43
- Joined: 09:54 pm Dec 01 2005
- Country:
Are jetting changes needed after head mod?
I just got my modded head back from RB, before I sent it I thought my jetting was right on(RB carb). Will jetting changes be needed with the new head?
96 KDX 200 H2
-
- Supporting Member II
- Posts: 1005
- Joined: 06:57 pm Mar 19 2005
- Country:
It should still be close.
A tighter squish (resulting in a better combustion) should allow you to lean it out a little from your previous jetting for a given temperature and alitude. Bottom Line - your engine should be a little richer (jetting wise) than it was prior to sending it to RBD.
A tighter squish (resulting in a better combustion) should allow you to lean it out a little from your previous jetting for a given temperature and alitude. Bottom Line - your engine should be a little richer (jetting wise) than it was prior to sending it to RBD.
KTM 380EXC Mine
KDX 200 Mark's
TTR 125 L Wife's
KDX 200 Austin's
EC 300 Tyson's
WR430 Husky - mine
KDX 200 Mark's
TTR 125 L Wife's
KDX 200 Austin's
EC 300 Tyson's
WR430 Husky - mine
- RBD
- Gold Member
- Posts: 210
- Joined: 02:00 am Jan 18 2005
- Country:
- Location: Portland, Oregon USA
- Contact:
-
- Supporting Member II
- Posts: 1005
- Joined: 06:57 pm Mar 19 2005
- Country:
-
- Supporting Member
- Posts: 60
- Joined: 11:34 pm Dec 13 2009
- Country:
Sorry for the rookie question. What is squish? And I presume you are saying one needs to install larger jets? What size (or is this obvious to experienced people?)?IdahoCharley wrote:It should still be close.
A tighter squish (resulting in a better combustion) should allow you to lean it out a little from your previous jetting for a given temperature and alitude. Bottom Line - your engine should be a little richer (jetting wise) than it was prior to sending it to RBD.
Thanks very much.
- SS109
- KDXRider.net
- Posts: 5793
- Joined: 05:11 am Aug 23 2009
- Country: USA
- Location: Tucson, AZ, USA
- Contact:
>|QBB|QBB<[/url]
Thanks very much.[/quote]
No, you would actually go to a smaller jet to get a leaner mixture.
As for squish, I hope this helps.
Sorry for the rookie question. What is squish? And I presume you are saying one needs to install larger jets? What size (or is this obvious to experienced people?)?IdahoCharley wrote:It should still be close.
A tighter squish (resulting in a better combustion) should allow you to lean it out a little from your previous jetting for a given temperature and alitude. Bottom Line - your engine should be a little richer (jetting wise) than it was prior to sending it to RBD.
Thanks very much.[/quote]
No, you would actually go to a smaller jet to get a leaner mixture.
As for squish, I hope this helps.
Youtube Channel: WildAzzRacing
AZ State Parks & Trails OHV Ambassador - Trail Riders of Southern AZ
Current KDX: '98 KDX220
Old KDX: '90 KDX200 -White/Blue
'11 GasGas EC250R
AZ State Parks & Trails OHV Ambassador - Trail Riders of Southern AZ
Current KDX: '98 KDX220
Old KDX: '90 KDX200 -White/Blue
'11 GasGas EC250R
-
- Supporting Member
- Posts: 60
- Joined: 11:34 pm Dec 13 2009
- Country:
Thanks for the great pic.
I'm confused then; IdahoCharlie says it needs to run richer, but that the extra squish let's you lean it out. Does this mean if you put rb head/carb on a stock bike it will be too rich, and the squish let's you lean it, but leaving it still richer than stock?
Thx.
Thought I already posted this.......
I'm confused then; IdahoCharlie says it needs to run richer, but that the extra squish let's you lean it out. Does this mean if you put rb head/carb on a stock bike it will be too rich, and the squish let's you lean it, but leaving it still richer than stock?
Thx.
Thought I already posted this.......
- fuzzy
- KDXRider.net
- Posts: 3437
- Joined: 01:29 pm Jun 18 2003
- Country:
- Location: Fredneck, MD
No, what IC was it will run richer with the tighter squish....therefore requiring you to lean it out. If you had stock jetting you were most likely in need of a re-jet anyway. Read up on here on how to jet your stuff. Once you know how, it's an indespensable tool.
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project