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FCR-MX installed, need some help

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Well everything went well, I have been riding my 2000S with the new FCR and open Yosh RS3. I am jetted to burned specs at sea level. 160mj, 45 pilot, fuel screw 2 turns out, 3rd clip on EMN needle, 3x3, etc. Overall great improvment but a few problems.

Bike wants to die at idle when warm, unless I crack the throttle slightly. Also it pops and gurgles alot on decel (i know some is normal) I was thinking of opening the fuel screw 1/4 turn but Im a newb, so whaddya think? Also I had a few drops of oil on the ground under the airbox vent after riding, could that be related somehow? ie filter issue?

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...... Overall great improvment but a few problems.

Bike wants to die at idle when warm, unless I crack the throttle slightly. Also it pops and gurgles alot on decel (i know some is normal) I was thinking of opening the fuel screw 1/4 turn but Im a newb, so whaddya think? Also I had a few drops of oil on the ground under the airbox vent after riding, could that be related somehow? ie filter issue?

Checkthis post out. The oil probably ran off your filter. It may have been over oiled.Search for oiling techniques and filter recommendations. Personally i would use No-Toil.

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Well I was unable to get to the fuel screw while it was runnning but I turned the fs out about 1/4 turn, helped a little but still lots of garble at decel. Guess I'll try another 1/4.

I forgot to mention that it is smoking alot, especially when revving at a standstill, (can't tell while riding) Is that anything to worry about? Bike is 2000 DRZ-S with only 2k miles.

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What colour is the smoke ???

I have also just fitted an FCRMX on a 2000 DRZ, I have my fuel screw at 1 turn.

Which is incidentally how it came out the box, I started at 2 turns, but that is far to rich, and produces lots of black smoke.

I also feel it is too rich on the needle range on the 3rd clip.

I have already dropped the main jet to 155 and may try a 152.

I am wondering if the recent FCR's have had the jetting changed.

I should have stripped the carb and checked it before fitting :applause::applause:

Guess I will do that tomorrow.

Neil. :thumbsup::ride::applause:

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Black smoke. I did not strip my fcr-mx and see what was installed, I just went off of what the paper said that came with it. Guess I should have confirmed it. The bike has more power but it garbles a lot and even bucks slightly when cruising at very slight throttle opening. That and wanting to die at idle...maybe I just need to turn the idle speed up...does turning the idle screw in raise or lower the idle? (I would try it now but Im at work)

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Black smoke. I did not strip my fcr-mx and see what was installed, I just went off of what the paper said that came with it. Guess I should have confirmed it. The bike has more power but it garbles a lot and even bucks slightly when cruising at very slight throttle opening. That and wanting to die at idle...maybe I just need to turn the idle speed up...does turning the idle screw in raise or lower the idle? (I would try it now but Im at work)

Sounds the same as mine was.

Have you tried this yet ?

Try going in on the fuel screw, to make it leaner, that should cure the slow cruising problem, and the lack of tick-over.

Screw the idle screw in for a faster idle.

Neil.

:thumbsup::ride::applause:

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stock fuel screw?

Good question, I forgot that one, even though I have already ditched my ZipTy one.

What is it with these extended screws, it's not as if they give them away.

Eddie, have you fitted any of these recent batch of FCRMX's, have they changed the stock jetting ??

It seems as if mine is rich all over, just a little, I have already fitted a 155 main, but it seems that I may need to drop the needle a clip as well.

Or is this because of my big bore ??

I know people have said that the big bore needs a smaller main jet, but no mentions about the needle as well :ride:

Neil. :thumbsup::applause::applause:

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not within the last month or so.i just put a 41 fcr-mx on a SM the other day and still had the jetting the other i did had.

i have a feeling your fuels are enough different on that side of the water to richen the jetting.seemed to be the same deal with your stock carb too??

what tells you its rich?

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what tells you its rich?

Initially the pilot circuit was coughing and spluttering at a steady throttle.

Then holding back, coughing and then clearing/pulling ok when opening the throttle.

The middle ranges of throttle is not particularly crisp, and the tail pipe has gone black, also smells of fuel.

The top end rips with the 155, but a mate following this evening said he can smell fuel, even when it has been wide open for over a mile.

Also the first tank of fuel hit reserve at 60 miles.

The fuel screw (stock) is at 3/4 turn out, and it has just started to pop slightly, on a shut throttle.

I think I'm going to try a 152 main, the needle on the 2nd clip (down), what do you think ?/

Neil.

:thumbsup::ride::applause:

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I'll let you know how it turns out.

If the fuel screw ends up at 3/4 turn out, is that a problem ??

I forgot to check what size pilot jet (fuel) was in it, but it should be the right one, YES (I hope).

It's just that the jets are very expensive over here, like $45.00 for 3 main jets.

I hate to think what the pilot jets cost, or how long it will take to get them.

Neil. :thumbsup::ride::applause:

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should be a 45,but i cant be sure as i dont know what supplier your carb came from.at least you can get the pilto jet out with out removing the bowl.

if its really 3/4,you should go to a smaller pilot.

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I'll check tomorrow, I assume it is the one beside the main jet then, if it comes out through the hex plug in the bottom ??

Labeled "Slow Jet" in the sudco diagram ??

Carb came from sudco, via TT Store.

Neil. :thumbsup::ride::applause:

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My problem is very similar to Neil's I think. My tailpipe is getting sooty and I get black smoke when revving. At very slight throttle opening, which I belive is using the pilot circuit, I get a lot of hiccups and sputtering. What I first thought was popping on decel was just the sputtering at slight throttle, when I decel with throttle closed is smooth w/no pop. (I am still getting used to this open yosh sound compared to the stocker)

So I think I'll take Neil's advise (thnks neil) and turn the fuel screw in a bit, maybe to 1.5 turns from closed and see. (currently at 2 1/4 turns out)

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I have a very similar issue to Neil and 1wheeldrive with my new FCR-MX kit from the TT store. I've gone back to the original fuel screw per Burned's suggestion, and that helped eliminate almost all of the bog, and the burbling/hunting, but the off idle throttle response still isn't crisp. Other than the off idle issue, the FCR-MX performs flawlessly.

AND, the bike runs best with the fuel screw turned all the way in? So, I believe the next step is a smaller pilot jet?

Burned, what size jet do you think I should try in place of the original 45 pilot jet?

Thanks!

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Update, I have confirmed the pilot jet to be a 45.

I now have a 152 main jet, needle on the 2nd clip.

The fuel screw is at 1/2 a turn out, and is still a little rich.

The needle range now feels spot on, the main jet is ok, but I feel that it may have lost just a tad off the top.

My mate now says he can't smell fuel when following, but I think I will probably end up back on the 155 main jet.

Eddie, so what size pilot jet do I need, and do you have a sudco part number ?

Neil.

:thumbsup::ride::applause:

PS: Before anybody copies my jetting, please remember this is for a 440cc engine with a cam and full system, running on UK fuel.

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