I have an 05 YZ250. It has a Vforce 3 and a Pro Circuit pipe. I have the jetting at a 182 main, Needle clip on the 3rd position, and 52 pilot. Air screw at 1.5 out. Its 59 degrees outside. The bike seems like it's stuttering when going up in the powerband and the plug doesnt have a drop of anything on it except gas. No soot. Funny thing is that there is a little black goo around the end cap on the silencer. What am I doing wrong? Do I need to go bigger on the main?
Help please. Does this sound like too much?
- Thread starter gonzo843
- Start date
I hate to say this, but welcome to the world of the VForce. Funny how these things do wonders on all bikes, except our own.
I had to go leaner in all directions with mine and never did get a great jetting set-up.
I had some success with mine when I dropped to a half-step leaner needle. Dont expect your shop to know the part number on the needle. My first attempt in ordering a leaner needle from PLAZA CYCLE resulted in my being 20.00 poorer and a needle two steps richer.
I had to go leaner in all directions with mine and never did get a great jetting set-up.
I had some success with mine when I dropped to a half-step leaner needle. Dont expect your shop to know the part number on the needle. My first attempt in ordering a leaner needle from PLAZA CYCLE resulted in my being 20.00 poorer and a needle two steps richer.
steve125
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- Oct 19, 2000
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Ok then, turn your idle screw out so you have no idle. Start with a 45 pilot jet with the air screw set a 2.0 out. And while your in there, put in a 175 main and get back to me. The clip position is fine in the 3rd slot. When you richened the needle clip from 2nd to 3rd, this also effects the pilot setting, since it all overlaps. You sound way to rich on the bottom to me. The V-3 reed is fine just work the jetting.
From all accounts I've heard that the V-Force 3 is all gains, no losses.
As far as the jetting issues go, I've never had them. I just leaned it out a bit and went riding. Some bikes are affected more than others. The late model YZ250 is easy to jet clean so you shouldn't have a problem.
As far as the jetting issues go, I've never had them. I just leaned it out a bit and went riding. Some bikes are affected more than others. The late model YZ250 is easy to jet clean so you shouldn't have a problem.
- Thread starter
- #9
I've heard all those good things too about the Vforce thats why I am surprised. So you really think I am running lean? The plug is like wet but not a soot black wet more like a "I dropped my plug in gas wet". Also the bike was fine before I put the pro circuit pipe on. Before I put it on though the plug looked almost fried it was so lean and I had no power on the bottom.
Also when you say idle screw your talking about the black one with a spring right? I havent been using that to set the idle. I have been using the throttle cable play. I tried turning the black screw because I thought it was the idle screw but that wasnt doing anything. I will try all this tommorow after work and let you know. I appreciate the advice guys. I have been riding for a while but this honestly my first 2 stroke so I am still learning.
Also when you say idle screw your talking about the black one with a spring right? I havent been using that to set the idle. I have been using the throttle cable play. I tried turning the black screw because I thought it was the idle screw but that wasnt doing anything. I will try all this tommorow after work and let you know. I appreciate the advice guys. I have been riding for a while but this honestly my first 2 stroke so I am still learning.
steve125
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gonzo843 said:
Gonzo, read again, I feel your running RICH not lean. The settings ive given you are to lean out the bottom mainly and a bit on top. Never set the idle with the throttle cable. Yes that black screw with the spring is the idle speed screw. Just back it out a few turns so the throttle slide is fully closing, but not so loose that it will vibrate out.
As far as plug readings go, it is only effective reading a plug for the "main jet" in a full throttle chop. The rest of the carby circuits, needle, pilot settings are all done by feel not plug readings!!!! At this stage of your learning on how to jet, don't worry so much about plug readings. For now lets make it simple. A lean setting feels like hesitation or bogging and sometimes pinging. Rich feels like blubber(rough running), excessive smoking, oily and dripping tailpipe. The speed range here is around 1/4 to 1/2 throttle that you need to work with at this time. You'll never hurt your bike if you go too lean or rich in the needle or pilot range that you are trying to jet at. Also always run some play in your throttle cable so the slide can fully close when snapped back. Good luck
Also when you say idle screw your talking about the black one with a spring right? I havent been using that to set the idle. I have been using the throttle cable play. I tried turning the black screw because I thought it was the idle screw but that wasnt doing anything.
I have yet to set up a modern bike that worked with the idle set high enough to idle. The throttle response goes to hell if the bike will idle for more than 10-15 seconds. It is much more annoying during warm up. Other than that it never presents a problem while riding.
I have ridden studboys 2002 with a v force and pipe. The bike is a rocket.
If you order jets and needles, look up the part numbers yourself. Dont expect your shop to know whick direction gives richer or leaner settings!
If you give up, the v-force ususally sells fr decent money on cbay....
I have yet to set up a modern bike that worked with the idle set high enough to idle. The throttle response goes to hell if the bike will idle for more than 10-15 seconds. It is much more annoying during warm up. Other than that it never presents a problem while riding.
I have ridden studboys 2002 with a v force and pipe. The bike is a rocket.
If you order jets and needles, look up the part numbers yourself. Dont expect your shop to know whick direction gives richer or leaner settings!
If you give up, the v-force ususally sells fr decent money on cbay....
I had the same issues mostly before adding the V-force 3 reeds... here is my post hopefuly it will give you a hand in jetting your YZ ...Keep youre new reeds! you will be glad you did!!! Jeff.
http://dirtrider.net/forums3/showthread.php?t=104368
http://dirtrider.net/forums3/showthread.php?t=104368
About the idle, When I get to the track I kick it over, one kick and it fires right up...then I get dressed ( full gear) and it will idle all day long if I let it...real smooth too :) so you can get yours in the same boat, just follow what I did to mine. I do however need to drop down on size on the pilot but it's nothing like it used to be to where I had "gas wet" plugs like you do now... Jeff.
- Thread starter
- #16
Well here's what I did. I reinstalled the Vforce this time really cranking down on the bolts. Then I put a 48 pilot and a 178 main. I also backed out the idle screw so it just sort of putters a second and stalls. So far it seems to be running alot better. I am not really able to test because the concrete roads in front of my house are soaked. What I did do though is got rolling and put it in third and let the motor go up from there. Yesterday it was sort of popping and stalling now its very smooth. I think I have it fixed. I will try tommorow and let you know. Thanks again for everyone's advice.
I wonder if your bike was running rich enough to clog up your silencer and soak the packing????
I also look back to when I was trying to jet a Derbi 50cc engine for a friend. I went through an unreal amount of jets trying to get it right. After several hours I remembered the lady sayign "I serviced the airfilter" I pulled it out and discovered she had used an entire bottle of bel Ray to oil the airfilter. After cleaning the filter and repacking the silecner the bike was easy to jet.
I also look back to when I was trying to jet a Derbi 50cc engine for a friend. I went through an unreal amount of jets trying to get it right. After several hours I remembered the lady sayign "I serviced the airfilter" I pulled it out and discovered she had used an entire bottle of bel Ray to oil the airfilter. After cleaning the filter and repacking the silecner the bike was easy to jet.
- Thread starter
- #20
Well the air filter is fine. Also I have only ridden the bike twice with the Vforce. I also just put a new pipe and silencer on the bike and still had the problem. Well see today. The crappy thing is that its going to be 71 today and 50 tommorow.
- Thread starter
- #22
I'm at sea level.
I went riding today. The bike was just amazing!!! It's perfect to just a tad rich. Today it was 70 tommorow it will be 50 so I am thinking to just turn the air screw in a half or so and I should be spot on for tommorow. The bike just rips now. Its so much smoother power too. It doesnt hit real hard the top end is incredible. As the mid range builds the bike really starts to get that arm ripping pull going into the top. I wasnt able to really wind out 3rd at the private place I was at today but tommorow I will be.
I went riding today. The bike was just amazing!!! It's perfect to just a tad rich. Today it was 70 tommorow it will be 50 so I am thinking to just turn the air screw in a half or so and I should be spot on for tommorow. The bike just rips now. Its so much smoother power too. It doesnt hit real hard the top end is incredible. As the mid range builds the bike really starts to get that arm ripping pull going into the top. I wasnt able to really wind out 3rd at the private place I was at today but tommorow I will be.
steve125
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- Oct 19, 2000
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Jetting is an amazing thing huh Gonzo? Sounds like the 45 pilot would have spot on like I said. But the 48 is fine just go out 1/2 turn, it amounts to the same thing really, unless you go past 3 turns out from all the way in. A properly set pilot jet will have an air screw setting from 1.5 to 2.0 out. Glad it all worked out :cool:
Gonzo, air screw out=leaner...........in=richer ;)
Gonzo, air screw out=leaner...........in=richer ;)
- Thread starter
- #25
Well and thats what I did originally. I was just trying to save myself some time and not take the shock off when I installed it. I didnt get to tighten it down well enough. After spending all this time though now it's great. I put a link to a pic from today. I guess you can post pics on this site huh?
Oh yea oops on the air screw. I knew what it was. Just after 2000 posts on thumpertalk my auto pilot had it backwards.
http://alexandjen.com/alexberm.jpg
Oh yea oops on the air screw. I knew what it was. Just after 2000 posts on thumpertalk my auto pilot had it backwards.
http://alexandjen.com/alexberm.jpg
