Rising Sun Member Forums  

Go Back   Rising Sun Member Forums > Other Hobbies > The Bike Forum

Reply
 
Thread Tools
  #71  
Old 04-16-2012, 12:16 PM
60wag's Avatar
60wag 60wag is offline
Rising Sun Member
 
Join Date: Aug 2005
Posts: 1,802
Default

The idle circuit should allow the bike to start even with the needle down low. How many turns from closed is the idle fuel screw?

Did you try starting it cold with the choke on?
__________________
Bruce
'96FZJ80
'03 KTM 450EXC
"If you know what you're doing, then you aren't learning anything." - A. Lincoln
Reply With Quote
  #72  
Old 04-16-2012, 01:52 PM
nakman's Avatar
nakman nakman is offline
Rising Sun Commander
 
Join Date: Aug 2005
Location: north side
Posts: 10,006
Default

Yes choke on, bike does not start otherwise. I will check the idle fuel screw tonight, that's the new red one on the bottom right? the plastic black one is just idle adjustment?
__________________
99 uzj100, 05 525EXC

www.gamiviti.com

Reply With Quote
  #73  
Old 04-16-2012, 09:01 PM
nakman's Avatar
nakman nakman is offline
Rising Sun Commander
 
Join Date: Aug 2005
Location: north side
Posts: 10,006
Default

Fuel screw was about 2 turns out, I put it back to 1.5. Will do my best to ride to work on Thursday and see if I can notice a difference.
__________________
99 uzj100, 05 525EXC

www.gamiviti.com

Reply With Quote
  #74  
Old 04-17-2012, 08:30 AM
60wag's Avatar
60wag 60wag is offline
Rising Sun Member
 
Join Date: Aug 2005
Posts: 1,802
Default

If you turn the fuel screw in until you get some popping when decellerating in gear, you have leaned out the idle circuit. If you can run the fuel screw nearly closed and the bike still idles without decel popping, then the idle circuit is running too rich for some reason.

Here is a nice summary on Keihin carbs. It's written for a different model but is very similar to the FCR.

http://www.gadgetjq.com/keihin_carb.htm

I like this graphic. I helps isolate the parts of the carb to different throttle positions.
Attached Images
 
__________________
Bruce
'96FZJ80
'03 KTM 450EXC
"If you know what you're doing, then you aren't learning anything." - A. Lincoln
Reply With Quote
  #75  
Old 04-17-2012, 10:15 AM
nakman's Avatar
nakman nakman is offline
Rising Sun Commander
 
Join Date: Aug 2005
Location: north side
Posts: 10,006
Default

Yeah that graph is helpful, thanks. So maybe I would have been alright on slot#3 then, if I had spent more time with the idle fuel screw? huh.
__________________
99 uzj100, 05 525EXC

www.gamiviti.com

Reply With Quote
  #76  
Old 04-17-2012, 10:49 AM
60wag's Avatar
60wag 60wag is offline
Rising Sun Member
 
Join Date: Aug 2005
Posts: 1,802
Default

What I don't get is why the needle position affects starting at all. That why I think something else isn't right.
__________________
Bruce
'96FZJ80
'03 KTM 450EXC
"If you know what you're doing, then you aren't learning anything." - A. Lincoln
Reply With Quote
  #77  
Old 04-17-2012, 11:26 AM
nakman's Avatar
nakman nakman is offline
Rising Sun Commander
 
Join Date: Aug 2005
Location: north side
Posts: 10,006
Default

I called JD just for fun.. they suggested routing my float bowl overflow tube up and over the carb, just to make any gas travel uphill before it can escape. Maybe I need to create a little back pressure there and gas is escaping out the tube that I just don't know about. the other suggestions was pull the carb and lower the floats, even if they measured in spec, make them lower. But in their opinion, there's nothing in their jetting that would account for such an increase in gas consumption.
__________________
99 uzj100, 05 525EXC

www.gamiviti.com

Reply With Quote
  #78  
Old 04-17-2012, 11:58 AM
60wag's Avatar
60wag 60wag is offline
Rising Sun Member
 
Join Date: Aug 2005
Posts: 1,802
Default

Does the tube from your gas cap to the frame have a check valve in it? You might try venting the tank to atmosphere to be sure that tank pressure isn't pushing fuel past the float valve. Also try the fuel screw thing to confirm that you can create a lean idle with decel popping.
__________________
Bruce
'96FZJ80
'03 KTM 450EXC
"If you know what you're doing, then you aren't learning anything." - A. Lincoln
Reply With Quote
  #79  
Old 04-19-2012, 12:19 PM
nakman's Avatar
nakman nakman is offline
Rising Sun Commander
 
Join Date: Aug 2005
Location: north side
Posts: 10,006
Default

Success? Rode to work today and I must say the bike's running as well as, or possibly better than, ever. Starts, idles, quickly jumps in RPM, and a slight amount of deceleration popping, all feels right. What's curious is I've learned that the ease of shifting has everything to do with how well the bike is running. I can find Neutral fairly easy now from 1st or 2nd, even while at a complete stop. When the bike runs poorly, it'll do anything from die when I shift into 1st, to just about refuse to go into Neutral either stopped or moving.. so for whatever reason, neutral shifting has become my litmus test.


Ok onto a question: I flipped the float bowl drain line up and over the carb, as directed by JD. while doing so, I realized that I do have some gas in the line that exits the top of the carb, on the other side (near where the throttle cables attach). Is this normal? or am I onto something here... the arrow points to where the gas was this morning when I rolled the bike out of the garage, first time I've touched the bike since Sunday.
Attached Images
 
__________________
99 uzj100, 05 525EXC

www.gamiviti.com

Reply With Quote
  #80  
Old 04-20-2012, 08:54 PM
60wag's Avatar
60wag 60wag is offline
Rising Sun Member
 
Join Date: Aug 2005
Posts: 1,802
Default

The tube with the arrow is one of the vents higher up on the carb. I think it's hard to get gas in that tube UNLESS the bike is layed over on that side. I've noticed a bit of gas in there when picking my bike up. It also seems to evaporate very slowly.

The bowl drain tube looped over the carb - any gas in it? That's the one that's more important. Fuel will drip out of that one, without tipping the bike, if the level in the bowl is too high.
__________________
Bruce
'96FZJ80
'03 KTM 450EXC
"If you know what you're doing, then you aren't learning anything." - A. Lincoln
Reply With Quote
Reply

Thread Tools

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 Off


All times are GMT -6. The time now is 11:19 PM.


Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.