ADVrider

Go Back   ADVrider > Bikes > Old's Cool > 2 smokers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-14-2014, 03:56 PM   #1
12120 OP
Indenturedx5
 
12120's Avatar
 
Joined: Apr 2012
Location: SW Washington USA
Oddometer: 347
Question general jetting ?

So in theory once you have your 2 smoker jetted for altitude/atmosphere etc.. what direction would you have to go for more bottum end/less hit. More trackable power in other words. Pondering a move to the 2 stroke side off things for a trail bike, and wondering if I can make a MX'er run better for trail riding.

Chris
__________________
If you find yourself in a fair fight, your tatics are wrong.
'83 XL 600r
12120 is offline   Reply With Quote
Old 09-14-2014, 04:11 PM   #2
JonnyCash
turd polisher
 
Joined: Jan 2011
Location: Midcoast, Maine
Oddometer: 1,422
That's not really a jetting issue. I mean, you could jet it really fat on the main jet, so that it would blubber at WOT, but that's not what you want. The power band can be moved around with pipe design, and also with porting. Advancing the spark timing can fill in the low end, but you risk detonation at high rpm that way.
__________________
I wouldn't bring her home to Mama, but Mama ain't home tonight.
JonnyCash is offline   Reply With Quote
Old 09-14-2014, 04:23 PM   #3
stainlesscycle
Beastly Adventurer
 
stainlesscycle's Avatar
 
Joined: Jun 2008
Location: morgantown, wv
Oddometer: 2,122
Quote:
Originally Posted by 12120 View Post
So in theory once you have your 2 smoker jetted for altitude/atmosphere etc.. what direction would you have to go for more bottum end/less hit. More trackable power in other words. Pondering a move to the 2 stroke side off things for a trail bike, and wondering if I can make a MX'er run better for trail riding.

Chris
easiest way is to add weight to the flywheel ...

jetting it to smooth out the hit could be accomplished with a combination of needle taper/needle jet or you can do it with pipe design. head reshape, or port adjustment can give you more bottom end, but that's kinda irreversible.

if you richen up the pilot, it would burble on the bottom, but when you got out of that circuit it would clean up and could cause an even more unrideable bike... you could jet it rich everywhere, but then you run the risk of fouling plugs, and having terrible performance when you want it. if you just richen the main it won't rev out, and burble... none of these are really good solutions.

throttle control is free, and can tame just about any bike...the more you ride a bike with an obnoxious hit, the more you learn throttle control....

or a slower throttle tube would work kind of..

what kind of mx'er are you trying to tame?
__________________
current bikes
07 gasgas xc300-94 duc 900ss-86 morini camel (2)-84 IT200-83 IT175-78 guzzi lm1-77 pursang 250-76 morini 3 1/2 strada-76 frankentaco pursang 200-74 frankentaco pursang 200-74 morini 3 1/2 sport-74 mz ts250/0-74 puch 175 (3)-73 can-am 175tnt-71 guzzi frankeneldo-71 ossa Stiletto-70 frankentaco sherpa s(2)-66 morini corsarino(2)-63 morini corsaro + many more
stainlesscycle is offline   Reply With Quote
Old 09-14-2014, 05:29 PM   #4
pdxjim
Two Stroke Terror
 
Joined: Sep 2009
Location: Portland, OR
Oddometer: 125
A heavy flywheel weight made my '00 CR250 unstoppable in the woods.

Really tamed the hit, and that thing would idle up a telephone pole (almost).
pdxjim is offline   Reply With Quote
Old 09-15-2014, 02:24 PM   #5
12120 OP
Indenturedx5
 
12120's Avatar
 
Joined: Apr 2012
Location: SW Washington USA
Oddometer: 347
That is what I was kinda thinking. Why not just put a flywheel weight on it. Don't know what kinda bike I might wind up with. I would really like to get something I can ride when the kids are on the 4 wheeler. Probly should just get a XR200.

Chris
__________________
If you find yourself in a fair fight, your tatics are wrong.
'83 XL 600r
12120 is offline   Reply With Quote
Old 09-16-2014, 03:43 PM   #6
ericm
Gnarly Adventurer
 
Joined: Sep 2002
Location: Santa Cruz Mountains, California
Oddometer: 275
Kdx200/220!
ericm is online now   Reply With Quote
Old 09-17-2014, 05:36 AM   #7
Bump Stop
2 Wheeled Drifter
 
Bump Stop's Avatar
 
Joined: Aug 2009
Location: finding Jesus
Oddometer: 5,448
Lots of pros ran flywheel weights on their bikes they should come factory with one.
__________________
10 GASGAS EC300, 06 Husqvarna WR 250, 05 KTM 250EXC, 04 GASGAS EC 200, 00 KDX 220, 74 250 Mach 1
www.fuzionllc.com
Bump Stop is offline   Reply With Quote
Old Yesterday, 07:11 PM   #8
caryder
Gnarly Adventurer
 
caryder's Avatar
 
Joined: Nov 2007
Location: Phoenix
Oddometer: 202
+1 on the KDX220. I have a flywheel & torque pipe. It's hard to stall and pulls well at low RPM but still has good top end. Nice well rounded bike for trail riding.


Chuck Ryder
__________________
Chuck
2012 Honda NC700X
2006 Gas Gas 300 Pro
2003 Kawasaki KDX220R
1976 Yamaha RD400C
caryder is offline   Reply With Quote
Old Yesterday, 07:34 PM   #9
_cy_
Beastly Adventurer
 
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 5,437
Quote:
Originally Posted by 12120 View Post
So in theory once you have your 2 smoker jetted for altitude/atmosphere etc.. what direction would you have to go for more bottum end/less hit. More trackable power in other words. Pondering a move to the 2 stroke side off things for a trail bike, and wondering if I can make a MX'er run better for trail riding.

Chris
you've not name a specific model .. assuming you've got a power valve that can be set to delay or advance hit .. timing can be changed by porting .. different pipes can be experimented with .. carb throat size can be reduced to increase low/mid range .. a heavier flywheel has already been mentioned.
_cy_ is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 06:13 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014