The $40 FCR Spruce Up

buzzard · Jan 11, 2007

While snowed in, it's time to fiddle with things. I read about these two products on this site, and decided to buy them, and install them. I have had an issue with the accelerator pump ever since I removed the carb, looked into the engine side of the carb, worked the throttle and squirted myself in the eye. Seriously, I have felt that the pump delivered too much fuel. This diaphragm has a taller metal pellet, which limits the stroke of the diaphragm. The end result is a pump stream of about .75-1.0 second, instead of the three second stream it has had. This kit from Honda includes the new diaphragm, o-ring seals, actuator rod (identical to stock one), aluminum pump cover, and a new spring. All for about $20. Then there is the new needle jet from Factory Pro (Factorypro.com), which has holes in it that the stock one doesn't. At their website, they have an amazing video of two carbs (one with, one without) showing how the stock one delivers fuel out of the needle jet in blobs, while the one with holes aerates the incoming fuel, delivering it as a mist. Again, about a $20 part. I have them installed, but have not thoroughly tested them. A couple of big donuts in the snow felt great. I have a bit of wonderment about the new aerating needle jet. Factory Pro says it will not affect jetting, yet it introduces air into the incoming fuel stream. Hmmm

husabutt · Jan 11, 2007

Hi Buzzard:

I couldn't find the video for the Factory Pro needle jet. Could you possibly post the link?

Also did you consider their Husaberg jetting kit that they sell? Does the kit come with the modified needle jet? It doesn't appear to.

Thanks,

Eric

sandskipper · Jan 11, 2007

buzzard,

Nice write up and information. Keep the group updated on your experiments and findings on these products as they do help other members in their quest for carburetor bliss. Keep the rubber side down.

Regards,

buzzard · Jan 11, 2007

Go to factorypro.com, choose Carb jets emulsion tubes on the lefthand column. It will take you to a long list of produucts, drop down to HDJ High dispersal jet, on the right hand side of that row will be a "click here", click it, and the video comes up. It is impressive. I talked with the folks at Factory Pro about the jet kit, and thought it was a lot of money for what is mostly a custom needle. I'm not that far off with what I have to need a new one, though I would love to test one without buying it! The gentleman at Factory Pro said that, in his opinion, no one had the FCR figured out very well. They developed their kits with a dyno, he said. I will definitely report back with results when the Arctic conditions subside a bit.

sethro · Jan 11, 2007

i tryed the honda diafram that you have there on my 07 650 and it produced a bad bog(lean) when I wacked the throttle open, not enough fuel , I had to go back to stock, may or may not be the case for everyone.

Sethro

Johnf3 · Jan 12, 2007

sethro said:
i tryed the honda diafram that you have there on my 07 650 and it produced a bad bog(lean) when I wacked the throttle open, not enough fuel , I had to go back to stock, may or may not be the case for everyone.

Sethro

There are lots of variables involved in jetting. I'm the one that brought up the use of the Honda diaphram here on this forum. A short (or even disabled) AP pump doesn't work right with the stock needle. Husaberg has the long AP squirt duration to "fill in" for the very lean stock needle. Once you change to a richer needle, you can alter the AP duration.

buzzard · Jan 12, 2007

Johnf3, can you tell me what needle you used? I wonder if the stock needle the CRF450X uses is a good starting place. My jetting dilemma has centered around the accelerator pump. When in tight going, on and off the throttle, it gets artificially rich due to the pump. I have not had the chance to try the new mods in trail conditions yet. Blazing around the yard in a foot of snow, it feels good. Also, with this Honda diaphragm, the stroke(duration) of the pump is somewhat adjustable by turning the adj screw. With the screw backed all the way out, there is nearly zero pump action. As you turn the screw in, you increase the pumps action. With the stock diaphragm, you had adjustment- lots, or really lots of fuel. This FCR had more accelerator pump action than the Q-Jet on my old Chev 454! Well, maybe not quite. I am determined to fully understand this FCR, and to learn how to make it do what I want it to.

sethro · Jan 12, 2007

Johnf3 said:
sethro said:

i tryed the honda diafram that you have there on my 07 650 and it produced a bad bog(lean) when I wacked the throttle open, not enough fuel , I had to go back to stock, may or may not be the case for everyone.

Sethro

Click to expand...

There are lots of variables involved in jetting. I'm the one that brought up the use of the Honda diaphram here on this forum. A short (or even disabled) AP pump doesn't work right with the stock needle. Husaberg has the long AP squirt duration to "fill in" for the very lean stock needle. Once you change to a richer needle, you can alter the AP duration.

I did replace the needle,

I have been using honda diaframs for long time with all my bikes with 41 pumpers, a good little trick, but the hussy 650 needs the fuel so back with the stock part, not that that is bad, runs like a ***** ape!!!!!!!!

Seth

buzzard · Jan 12, 2007

I couldn't stand it any longer, I went for a snow ride today. Climbed some snow hills, roosted in rocks and ice. I do have a lean condition cracking the throttle at times. However, it runs better than ever excepting that! After some research on the internet, and at the local Honda dealer, I found that the CRF450X comes stock suited to meet EPA certification. It too has the same lean condition. Honda never quits amazing me. They make a needle that goes in the 450X if it doesn't need to meet EPA regs. Honda part # 16233-MEN671. I have one ordered. It will be here next week. I will install, and dutifully report the results. Of course, it is $20. This will be a $60 spruce up before it's done. We're getting close! As a postscript, Sorrels are not bad riding boots.

husabutt · Jan 12, 2007

Since your in the mood for testing................

http://www.slavensracing.com/p_nobog.htm

Taffy · Jan 13, 2007

buzzard

would be very interested in the results of the aerorated atomiser? however, if you do two tests at once the results are invalid mate.

on the basis that you ignored the advice offered here for jetting you must have wanted to search a new route. no problems from me but you have always had the ability to adjust the duration and strength of your APJ squirt for free (or the cost of fitting an adjustable spring-loaded screw).

the bogging can be a rich condition as well as lean. try lowering the MJ 10 and raing the needle once and then once again in tests. this will cure the bog.

regards

Taffy

buzzard · Feb 5, 2007

I've been anxious to be able to report back on my Frankencarb experiments, and today is the day! It got above freezing, and some dirt was poking through in the badlands near Delta, CO. A riding we went. To bring those new to this story up to speed, I have swapped out my accelerator pump diaphragm (on my FCR carb on a 2006 FE450e) for one from a 2006 Honda CRF450r, replaced my needle jet with the HDJ needle jet from Factory Pro, and have added a needle from Honda, an NCVS, in pos 3. I have a 165 main, 42 pilot, and my fuel air screw is 2 1/8 turn out. Do note that I am running at 5000' altitude, and it was about 35'F today. My 450 ran better than I thought possible. It hit smooth and hard right off idle, never a stumble or cough. Power built nearly linearly, with a top end I never did fully explore. It now runs like I feel a modern 450 should, a little mellower than a CRF450r down low, and building to an exciting rip at midrange on up. I have in the past regretted not buying the 550 at times, on certain rides. No more. My 450 runs like it is an open class four stroke now. This turned out to be a $60 carb build up, and worth every cent! I do believe that if I were doing this for a 550, I would consider the NCVR needle, one step richer (less root diameter). For anyone brave enough to read this far, I will add a note about my forks. I replaced the .44 springs with the .46, lessened preload (it had almost 20mm stock, I'm at 10mm now), and changed the fork oil to 2.5W with a 110mm air chamber. 15 clicks rebound, 19 compression. They work superbly, gone is the tendency to deflect in rocks, no bottoming, supple and smooth, keeping the wheel in contact with the dirt much more often than before. I weigh 205lb, and ride like the out of shape retired guy that I am. I was intending to rid this carb of any EPA compliance gremlins, and did so. Also, for those who have FCR carbs robbed off a Yammie YZF, do realize that your carb was never set up like the carb on a newer Berg. And if interested, look at the latest Cycle World magazine, in it they mention the de-EPAing of an editors new Husqvarna TE510, an interesting bit.

fryguy · Feb 6, 2007

Have any of you guys replaced the bleed back jet in the bottom of the AP? A friend had bog on his big bore 250f after he installed a richer needle and traced it to the AP as it was overfueling. He spent $10 on the jet the controls the fuel bleed back into the float bowl. Just curious if it works or its just his story?

cool findings buzzard

buzzard · Feb 6, 2007

fryguy, much of the useful info I could dig up on the FCR came from my friends CRF450r owners manual. It has about 12 pages of excellent tuning and operational guides on the FCR. I copied them. The leak jet is used to adjust the flow of fuel discharged by the AP. It does this by bleeding off a portion of the fuel pushed out by the diaphragm. A larger leak jet will lessen the AP squirt to the intake, a smaller leak jet will increase the flow to the intake. If on rapid throttle openings, your engine is gasping for more fuel, you need a smaller leak jet. If it stumbles from over-rich condition on throttle openings, you need a larger leak jet. A 55 is standard on a CRF450. I have not looked to see what my FE450 came with.

Taffy · Feb 6, 2007

fryguy

your freinds story is likely to be true though i doubt he has invented the wheel here. the yams had a torrid time with the leak downs in 2003 or so.

regards

Taffy

LINEAWEAVER · Feb 7, 2007

Relevant Thread

What!, no accelerator pump? Are you insane?.

Read down to carburetor content:
http://www.husaberg.org/index.php?name= ... ineaweaver

Lineaweaver Jet Kit

Dynamometer Graphs available in my Gallery.

Dale

buzzard · Feb 7, 2007

After another day of riding, I have this to say: If you have a Husaberg that came with an FCR carb, rejet-recalibrate it! It will be the best money spent. Period. I don't care if you go with Dale Lineaweaver's kit, Taffy's recommendations, JD Jetting, or catch a hint of what I did. Get rid of the three second AP squirt diaphragm, get a richer needle, and jetting to work with your needle of choice. Wean your baby off the AP ***, and get it running on jets and needle. There is a beast lurking within your Berg, waiting for this attention. Also, my salute to Mr. Lineaweaver and Taffy, who have long sang this song, if maybe along a different path.

steve · Feb 8, 2007

Hear Hear,

Taffy's setup tips applied to my 501 works a treat and the Lineaweaver kit in my 650 along with the TPS disconnected is wonderful as well. AP is not needed.

Steve

chills · Apr 17, 2007

Hi Guys,

Dale Covington contacted me through ThumperTalk.com in search of a CRF450 Manual. I have provided him with a link to the manual through our Private Messaging which he is free to share the link for DL with any of you who are interested.

In reading through your posted, and troubleshooting the AP pump, BVB along with myself, Armourbl, and Jimbo45 went through some extensive testing with the AP squirt, linkage, diaphragm, Leak Jets, and tuning. I put together an extensive PDF manaul with all of the information related to fixing the bottom end bog that most 4-strokes have by nature.

As it relates to the post about getting rid of the AP pump. The AP pump was designed to overcome the lack of vacuum needed to pull fuel through the jets due to the 4-stroke running at a much lower RPM than a 2-stroke. Therefore, the AP Squirt is was gives it the fuel it needs. Honda realized in 07 what we put together in our testing and manual and changed the carb to accomidate the changes. We have been successful in modding 03, 04, 05, and 06 CRF450 along with the CRF250F carbs with this AP Mod. While this mod is free to do, changing the Leak Jet that is located at the bottom of the fuel bowl is required for spot on throttle response. While some throttle bog in noticed when wrapping it on the stand, there wasnt any bog noticed on the track.

With a Stock lets say 06 CRF450 Carb, if you remove the throttle drum cover, you can see the AP Link Lever, AP Linkage Rod, and the AP Set Screw. When you open the throttle to WOT, you notice a GAP between the AP Set Screw and the AP Link Lever, this gap is due to the rivet located on the AP Diaphragm, which is bottoming out on the AP Cover. By shaving down the rivet 2-3mm on the AP Diaphragm, and putting everything back together, you now can pull the throttle to WOT and the AP Link Lever and AP Set screw stay matted together, even at WOT now. The next step, because the AP Link lever is spring loaded, and the AP Linkage Rod is overcoming pressure when opening throttle, there can be some delay due to the spring tension. There is no spring replacement for a tight spring, therefore, wiring (Safety Wiring) the AP Link Lever to the AP Set screw bracket, allows a unison movement of the AP Link Lever with the exact throttle response location, therefore, the AP Squirt is exact. Now, to counteract that precise squirt of the AP, since its a little rich, changing out the Leak Jet, which is located at the bottom of the fuel bowl, to a #90, seems to be the best all around spot on performance. I currently have a #80 in mine, have 102hrs on it, with no degrade in the AP Diaphragm, so if there is any worries in reliability, 102hrs are the mark thus far.

Like I said, Honda has fixed this AP Mod with changes to their carb for 07...

I hope this was useful, you can DL the AP Mod here: (Right-Click and Save As)

http://www.squadpage.com/pandora/Profes ... %20Mod.pdf

Thanks,

Chris Hills - AKA- Chills

buzzard · May 6, 2007

I wanted to follow up on one item that was left hanging from my carb experiments. The Factory Pro atomizing needle jet was one component I used, and I neglected to see exactly what effect that item alone had upon carburetion. I will start by saying this: We have recently jetted both a 450 and a 550 as I have my own bike jetted, less the FP needle jet. Both bikes were a major improvement over stock jetting, but lacked that "it's just perfect!" off idle response. So for the 550, we ordered the FP jet. The mailman arrived and we installed it. Presto! It's perfect! As the owner of the 550 stated, "It's a thousand percent improvement". This $20 part has an amazing effect upon response right off idle. Also, to my suprise, the 550 ended up liking the same jetting and needle that my 450 likes. Somehow, I assumed that the larger displacement motor would like a richer needle or something. I have read, and somewhat believed, several articles about the reasons a larger(or smaller) motor needs different jetting. It may be true, but right here at 6000', that 550 likes the same jetting as my 450. That jetting is: Using the Honda AP diaphragm, Factory Pro atomizing needle jet, NCVR needle pos 3, 165 Main, 42 pilot, fuel/air screw 1 1/4 turns out. I would be curious to know how the needle jet affects a stock jetted bike. For $20, I hope someone gives it a try and lets us know.

Search

Search

The $40 FCR Spruce Up

buzzard

Attachments

husabutt

sandskipper

buzzard

sethro

Johnf3

buzzard

sethro

buzzard

husabutt

Taffy

buzzard

fryguy

buzzard

Taffy

LINEAWEAVER

buzzard

steve

chills

buzzard

Attachments

Similar threads

Register CTA

Recent Discussions

Recent Discussions