ADVrider

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-08-2007, 06:09 PM   #61
00jmc
n00b
 
Joined: Apr 2007
Oddometer: 1
41 on a Duke

Sorry to jump in here guys but I need some help w/the 41 on my Duke. The bike is new to me and the previous owner put the 41 on this past winter. Does the 41 have a choke or is there a secret to starting w/out it? The previous owner just said it didn't have one. Please help, hard to start in this 30 degree weather!
00jmc is offline   Reply With Quote
Old 04-08-2007, 09:28 PM   #62
lvdukerider
Las Vegas Nevada
 
Joined: Oct 2003
Oddometer: 523
Quote:
Originally Posted by 00jmc
Sorry to jump in here guys but I need some help w/the 41 on my Duke. The bike is new to me and the previous owner put the 41 on this past winter. Does the 41 have a choke or is there a secret to starting w/out it? The previous owner just said it didn't have one. Please help, hard to start in this 30 degree weather!
It has a choke knob on the upper left side of the carb, its kind of hidden by the tank. I used the old choke plunger off the BST40 by simply cutting and fileing off the brass protrusion in the center, so I could retain the handlebar choke control.
lvdukerider is offline   Reply With Quote
Old 04-08-2007, 09:53 PM   #63
Flyin Brian
Gnarly Adventurer
 
Flyin Brian's Avatar
 
Joined: Jan 2006
Location: Bend, Oregon
Oddometer: 227
Damn Bog!

I haven't ran across Creepers update on his FCR install, but I'm getting closer to going that route. Last year when I first got the bike it bogged out after going through minor whoops (really annoying). After reading through all the info on this site. I got the carb all cleaned out and adjusted properly over this past winter. Well the bog was gone, and I was happy. I figured the FCR would be a performance addition only, not a bog remedy. Well today the bog came back. Of course it happens when you really can't afford it. I was starting up a hill climb and had to go over some whoops at the start of the hill. Well the damn bike just starting sputtering and died. I had to let it sit for a few minutes before it would run correctly again.
So in the short term whats that best way to get the bike running properly (besides waiting) after suffering from the bog? Long term..... I'm looking for a FCR.

Creeper..... How's that FCR doing for you? Elevation changes an issue?

On another note.. .It was great day riding. The conditions are perfect out here in the high desert!
Flyin Brian is offline   Reply With Quote
Old 04-09-2007, 05:53 AM   #64
losiu OP
wheelie addict
 
losiu's Avatar
 
Joined: Jan 2004
Location: POLAND
Oddometer: 577
It is possible to start a bike that has a pumper carb without using the choke by simply whacking the throttle open a couple of times before you start it. The pump will squirt some gas where it's supposed to go and the bike should start. I believe the choke would simply work better because it's designed to help start cold engines and it definitely IS on the left side of the carb.

Depending on the carb model, there'll be one black knob that you pull or two - black and red. I've never had an FCR but the red one should be for "HOT START".

The BST is a total PITA sometimes. I have no time to do much offroading but I know from experience that it's simply unpredictable. Sometimes it works fine and sometimes it doesn't. Properly re-jetted and set up it probably could be comparable to pumper carbs but it needs to be said: It'll never be/beat a PUMPER CARB.

I've ridden several bikes with pumper carbs since starting this thread and I know that the bikes tend to be smoother and even if they don't provide jaw-dropping performance in comparison with the BST, they are fully predictable and don't cause problems when off the road.

I think I'd choose an FCR39 for my riding style. Thank you all for posting your experiences :)

Losiu
__________________
KTM 690 R - The new wheelie weapon
Husqvarna TE 250 - The little beast
Husqvarna 333R - The ...umm..... how do I put it....
losiu is offline   Reply With Quote
Old 04-11-2007, 09:26 AM   #65
humdinger
bp
 
humdinger's Avatar
 
Joined: Feb 2006
Location: South eastern coast , Australia
Oddometer: 616
Finally got the FCR and Akro on.....

After a long wait, I've got the FCR 41 and full Akro system installed on my '05 640 Adv.
Totally different bike. The engine is super responsive and silky smooth. So much so that the bike 'feels' 20 kgs lighter even though I think I only dropped about 6 kgs. Stripped all the SAS crap off and 'bunged' the hole between the exhaust ports. No more backfires!
This is how she's jetted and set up:

170 main
45 pilot
Fuel mixture 1 and 3/4 turns out
Blue needle (JD Jetting) clip on 5th down from top
Didn't adjust pump duration; left stock at 3 secs.
Elevation: 0 to 4000ft
75% + humidity
22 degrees centigrade (Average; varies from 15 to 26)

The big girl really pulls hard from pilot all the way to WOT and I was surprised how much better it 'torques' along at low revs, especially when doubling. She's a tad rich down low but seems spot on every where else.
I can start her cold with a couple of short twists from the throttle and hot starts just require a short stab on that magic black button.
Overall, the installation was pretty easy, even for some sub-standard grease monkey like myself. The Akro system was a little close to the frame in a couple of areas but otherwise a lovely fit. I routed the new (slightly shorter) throttle cables down the RHS of the backbone and simply removed the existing connection plugs from the wiring harness that serviced the BST. I didn't have to re-route any wiring which runs top RHS of the new carb. All fuel lines and overflow tubes run neatly away from the exhaust.
The stock gearing of 16/42 is perfect for the road but I'd like maybe a 45 tooth rear for the scrub. Haven't looked at fuel consumption yet but I'm thinking it will be more than that of the BST.
Was it worth the money? That's debatable to some but like the saying says:
"It's a long time, dead!"
I can honestly say that the 640 feels like a fire breather now with a new lease on life!
__________________
'05 640 Adventure
humdinger is offline   Reply With Quote
Old 04-11-2007, 10:25 AM   #66
potatoho
Cheese and Rice!
 
potatoho's Avatar
 
Joined: Aug 2004
Location: Sea-level
Oddometer: 4,687
Quote:
Originally Posted by losiu
Properly re-jetted and set up it probably could be comparable to pumper carbs but it needs to be said: It'll never be/beat a PUMPER CARB.
Personally I feel you'd need to hack on a pumper to make it equal a CV carb

When I went back to the BST I hooked up an air-fuel meter because I wanted to get to the bottom of things. Sure enough, there was a mammoth dip right off-idle, going from about 12.5:1 pegging to beyond 15:1. The motor sound was hardly even noticeable, it only sounded slightly rough. However it was very weak. So at low rpm the motor tolerates a really wide range of mixtures without giving much of an indication to the rider.

My needle was worn and it caused the taper to be completely incompatible with the motor. If you adjusted it for mid range, it would be too lean off-idle, and if you adjusted for off-idle, it would be far too rich in the mids. When I put in a new needle, I was able to adjust to the normal clip positions and not have those anomolies. The off-idle was like SNAP!

So unfortunately, I think the CV carb tends to wear out the parts a bit more. My needle jet is also obviously ovalled, which is another thing probably throwing off my mixtures from the accepted settings. I haven't had any complaints with the performance once I got the breadth of the throttle mixtures worked out.

The real fun will be experimenting with airbox flow and exhaust flow and how it relates to realworld power. It is kinda cool watching the mixture change when you add the side cover, and then the seat etc.
potatoho is offline   Reply With Quote
Old 04-11-2007, 10:33 AM   #67
Some Dude
what attitude problem???
 
Some Dude's Avatar
 
Joined: Dec 2003
Location: Woodstock, GA
Oddometer: 4,704
I had a 98 620 SX that had the Delorto piece of crap on it, it was a pain to hardstart and impossible to keep running consistantly from clogged idle passages to you name it. I ditched it after being stranded on the side of a mountain in single track and not able to restart the bike after it bogged to a stall.

I then installed the FCR 41mm kit from sudco, in my discussions with them I had asked specifically about hot start operation on the kit. Well to my disappointment they do not offer an FCR kit for the LC4 with hotstart as a feature. So I then threw a fuss and they sold me an FCR 41 MX style carb at a hefty discount. This was like heaven. The bike was wheeling good in 2nd gear and a slight pull up was needed to loft it in third, with the FCR MX it was able to pull a wheelie all on its own in 4th gear on power alone. It turned it into a monster that was easy to hot start when the time came. After riding a few LC4's with both the BST and Delorto, I wouldn't own one without the FCR.
__________________
Just some dude on the internet,..
Some Dude is offline   Reply With Quote
Old 04-11-2007, 10:37 AM   #68
Lornce
Lost In Place
 
Lornce's Avatar
 
Joined: Aug 2003
Location: Way Out There.
Oddometer: 17,892
Quote:
Originally Posted by potatoho
Personally I feel you'd need to hack on a pumper to make it equal a CV carb

When I went back to the BST I hooked up an air-fuel meter because I wanted to get to the bottom of things. Sure enough, there was a mammoth dip right off-idle, going from about 12.5:1 pegging to beyond 15:1. The motor sound was hardly even noticeable, it only sounded slightly rough. However it was very weak. So at low rpm the motor tolerates a really wide range of mixtures without giving much of an indication to the rider.

My needle was worn and it caused the taper to be completely incompatible with the motor. If you adjusted it for mid range, it would be too lean off-idle, and if you adjusted for off-idle, it would be far too rich in the mids. When I put in a new needle, I was able to adjust to the normal clip positions and not have those anomolies. The off-idle was like SNAP!

So unfortunately, I think the CV carb tends to wear out the parts a bit more. My needle jet is also obviously ovalled, which is another thing probably throwing off my mixtures from the accepted settings. I haven't had any complaints with the performance once I got the breadth of the throttle mixtures worked out.

The real fun will be experimenting with airbox flow and exhaust flow and how it relates to realworld power. It is kinda cool watching the mixture change when you add the side cover, and then the seat etc.

Wow.

This is the most interesting post I've seen in ages. Would love to hear more about your mixture analyzer as you have time to post.

!!!

Lornce
Lornce is offline   Reply With Quote
Old 04-11-2007, 10:47 AM   #69
potatoho
Cheese and Rice!
 
potatoho's Avatar
 
Joined: Aug 2004
Location: Sea-level
Oddometer: 4,687
Quote:
Originally Posted by Lornce
Wow.

This is the most interesting post I've seen in ages. Would love to hear more about your mixture analyzer as you have time to post.

!!!

Lornce
I started this thread:
http://www.advrider.com/forums/showthread.php?t=209038

The dial-a-jet is a bust so far. The BST was running good on the last ride. I think the exhaust leakage I suspected had more to do with my motor's freak-out response to an anemic mixture in the mids. Seems if I get below a certain ratio it will freak out. The needle was eccentric and making it hit a weird mixture spot. With my new needle I was able to start bumping it up and it settled down and stopped with the weird anomolies.

I need to increase the rear suspension on the bike before riding it again. The motor ran fine however.

I should mention that trond tested a BST and an FCR with the same meter. He did settle on the FCR, so my statement about the BST being better than a pumper is not shared. I just think it has more potential if you were to adjust the damping and spring rate, or if we had some more needles to work with. Also the BST isn't the only CV carb available.
potatoho is offline   Reply With Quote
Old 04-11-2007, 11:26 AM   #70
Flyin Brian
Gnarly Adventurer
 
Flyin Brian's Avatar
 
Joined: Jan 2006
Location: Bend, Oregon
Oddometer: 227
Quote:
Originally Posted by humdinger
After a long wait, I've got the FCR 41 and full Akro system installed on my '05 640 Adv.
Totally different bike. The engine is super responsive and silky smooth. So much so that the bike 'feels' 20 kgs lighter even though I think I only dropped about 6 kgs. Stripped all the SAS crap off and 'bunged' the hole between the exhaust ports. No more backfires!
This is how she's jetted and set up:

170 main
45 pilot
Fuel mixture 1 and 3/4 turns out
Blue needle (JD Jetting) clip on 5th down from top
Didn't adjust pump duration; left stock at 3 secs.
Elevation: 0 to 4000ft
75% + humidity
22 degrees centigrade (Average; varies from 15 to 26)

The big girl really pulls hard from pilot all the way to WOT and I was surprised how much better it 'torques' along at low revs, especially when doubling. She's a tad rich down low but seems spot on every where else.
I can start her cold with a couple of short twists from the throttle and hot starts just require a short stab on that magic black button.
Overall, the installation was pretty easy, even for some sub-standard grease monkey like myself. The Akro system was a little close to the frame in a couple of areas but otherwise a lovely fit. I routed the new (slightly shorter) throttle cables down the RHS of the backbone and simply removed the existing connection plugs from the wiring harness that serviced the BST. I didn't have to re-route any wiring which runs top RHS of the new carb. All fuel lines and overflow tubes run neatly away from the exhaust.
The stock gearing of 16/42 is perfect for the road but I'd like maybe a 45 tooth rear for the scrub. Haven't looked at fuel consumption yet but I'm thinking it will be more than that of the BST.
Was it worth the money? That's debatable to some but like the saying says:
"It's a long time, dead!"
I can honestly say that the 640 feels like a fire breather now with a new lease on life!
Do you have a parts list for just the FCR install? Did you purchase a new carb, or find a used one from another bike? Thanks in advance.
Flyin Brian is offline   Reply With Quote
Old 04-17-2007, 11:33 AM   #71
rideaholic
Gnarly Adventurer
 
Joined: Nov 2006
Location: Pittsburgh, PA
Oddometer: 229
I have the quickslobber on my 97 RXC 620. I have torn it down 5 times thinking I could fix it's problems. I don't think there is a snowball's chance. The problem is anytime I hit a jump or bump the engine dies. Can be very dangerous at times. It has a K10 jet and a KTM MX exhaust. I have other jets, but have not done a plug check yet. Any suggestions on a fix or should I just spend the $$$?

Thanks
rideaholic is offline   Reply With Quote
Old 04-18-2007, 05:23 PM   #72
rideaholic
Gnarly Adventurer
 
Joined: Nov 2006
Location: Pittsburgh, PA
Oddometer: 229
I adjusted the float level and all seems fine now. I guess I will see. I am still buying a new carb though.
rideaholic is offline   Reply With Quote
Old 04-30-2007, 01:53 AM   #73
ridelikeistoleit
slappy the hamfisted one
 
Joined: Apr 2007
Location: Evansville Indiana
Oddometer: 100
lc4 carb

hey,can't say much but I changed my 96 rxc 620's edeljunk[stick to what you know,car guys]to a fcr39 [paid to have installed,tuned,bought new domino twist grip,and modded air boot and don't think it was close to 1100,but was'nt cheap]and it was a night and day difference!always been good at wheelies but now I'm ggrreeaatt![okay,a little goofy too] throttle modulation is great and control exact throughout rev range-bottom to top!I dont know bst's or dell'oto's but this thing aint broke now so I ain't fixin it!
ridelikeistoleit is offline   Reply With Quote
Old 12-17-2007, 08:33 PM   #74
rapiti
IOR Veteran
 
rapiti's Avatar
 
Joined: Mar 2003
Location: On the island
Oddometer: 1,897
I wish I had read this before my latest round of ebaying.

I just bought an FCR 39 off a YZF450. I was unaware that physical dimensions varied so much. I think I got the wide one

Any advice? Read the bleeping thread?!
__________________
...its the best paint scheme that has ever been or ever will be on an Adv...-AussieRob
rapiti is offline   Reply With Quote
Old 12-17-2007, 08:46 PM   #75
rideaholic
Gnarly Adventurer
 
Joined: Nov 2006
Location: Pittsburgh, PA
Oddometer: 229
I am not sure if that's the same style carb as I just bought, but the FCR I just bought and intalled was off a CRF 450. My gas inlet is different and I have a black plastic cover. I put it on a 97 RXC 620. It was a snug fit, but fit it did. I had to make an aluminum adapter to extend the length a little and also changed the screw that held on the cover for the cables. It started very easily. The jetting is close, but I plan on making it perfect as soon as the weather around here in Pittsburgh, PA starts to cooperate.

Maybe post some more pics of other angles of the carb. If you can't get the carb to fit, just sell it on ebay, forums, or craigslist. You shouldn't lose too much $. Good luCK.

rideaholic screwed with this post 12-17-2007 at 08:57 PM
rideaholic 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 02:12 PM.


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