Hey guy's
I got a question or two for any one that has done this conversion. I did a Dynojet stage 1 conversion although I am using 4 uni independent filters rather then the stock air box with a hi flow filter as suggested in the instructions. The bike ran great for a while and then got left out in the rain one afternoon which turned into one of Florida's famous gully washers. After that the bike ran like crap. A buddy and I let it dry out and attended to some electrical problems that was causing coil 2/3 to fire intermittently. we pulled the carb's cleaned out the bowls, inspected the slide diaphragms to find one with a razor thin slit which I replaced with a good used one. I made the necessary modifications to the new slide reinstalled every thing and the bike seems to be running rich. I have set the pilot screws to 3.5 turns as recommended. The bike starts with the choke but sucks down the fuel from the aux tank we fabricated and you can see the fuel rich vapor coming out the stock pipes. I am running auto light plugs a Dyna 2000 digital ign. system and a pair of Dyna coils purchased and installed at the same time.
Any suggestions on how to lean out the excessive fuel mix. I am sure it has something to do with eather the pilot sscrews or the potion of the washer on the slide needles but just dont have the necessary experience to fix this. thanks in advance for any and all help
Stan the man Orlando. ???
Sounds like a float/fuel level problem to me.
i would turn those pilot screws in some.... i ran mine about 2.5 turns out.
easiest way to tell when the pilot circuit is correct is to do the blip test.... get engine warmed up
blip throttle and rev the engine..... if the engine speed hangs and slowly returns to idle then its too rich- turn misture screws IN
blip throttle.......if engine speed drops quickly to below idle set point then recovers you are too lean... turn mixture screws out.
make sure carbs are synched properly (on a warmed up engine) before adjusting mixture screws
KOokaloo!
Frank
Aren't the pilot screws on the stock carbs *air* screws rather than fuel? (I should know the answer to this by now, but I can't remember shit and I'm no David Rayforth.) At any rate, 3.5 turns seems excessive. I'm running a similar setup, pods and a Factory Pro Config One jet kit, stock ignition and the screws are 2.25 to 2.5 turns out.
Rossi
Quote from: rlucas on February 12, 2009, 08:32:53 PM
Aren't the pilot screws on the stock carbs *air* screws rather than fuel? (I should know the answer to this by now, but I can't remember shit and I'm no David Rayforth.) At any rate, 3.5 turns seems excessive. I'm running a similar setup, pods and a Factory Pro Config One jet kit, stock ignition and the screws are 2.25 to 2.5 turns out.
Rossi
Rock your running uni pods and a Factory pro stage one kit? Very cool.....I'm planning on doing the same, but was told by some that a stage 3 is what I should use. Did you use the settings from FP that came with the kit? or did you need anything else.. TIA
Eric M
Quote from: rlucas on February 12, 2009, 08:32:53 PM
Aren't the pilot screws on the stock carbs *air* screws rather than fuel? (I should know the answer to this by now, but I can't remember shit and I'm no David Rayforth.) At any rate, 3.5 turns seems excessive. I'm running a similar setup, pods and a Factory Pro Config One jet kit, stock ignition and the screws are 2.25 to 2.5 turns out.
Rossi
Nope, they're fuel screws..... msot 4t carbs use fuel screws, 2t carbs use air screws.
He's right, they adjust fuel, not air.
Here's some potentially helpful information for you.
http://www.dynojet.com/pdf/4127.pdf (http://www.dynojet.com/pdf/4127.pdf)
http://www.factorypro.com/tech/carbtune,CV,high_rpm_engines.html (http://www.factorypro.com/tech/carbtune,CV,high_rpm_engines.html)
If you get lost, here's (http://www.bfmoto.com/pages/parts/viewbybrand/2/Yamaha.aspx) a fiche to play with, though the OEM isn't great at showing what's where.
If it's only rich at idle/small throttle openings, you're on the right track, you'll probably need to go with smaller pilots. If you're rich in the midrange, the needles can come down some.
First thing I'd look at is just how much oil is on the airfilters, though. Just knock them off and see if it runs better, if they're oiled correctly they make almost no restriction at all.
Quote from: andyb on February 13, 2009, 04:58:01 AM
He's right, they adjust fuel, not air.
Actually that's not correct either. The mixture screws are both and neither. They adjust the amount of an idle circuit air/fuel mixture that results from the interaction of the idle air pilot jet and idle fuel jet. To change this idle circuit MIXTURE, you change either the air pilot jet or the fuel jet. The mixture screws just control the amount of this mixture that flows into the intake tract.
Quote from: Yamifj1200 on February 12, 2009, 08:56:00 PM
Quote from: rlucas on February 12, 2009, 08:32:53 PM
Aren't the pilot screws on the stock carbs *air* screws rather than fuel? (I should know the answer to this by now, but I can't remember shit and I'm no David Rayforth.) At any rate, 3.5 turns seems excessive. I'm running a similar setup, pods and a Factory Pro Config One jet kit, stock ignition and the screws are 2.25 to 2.5 turns out.
Rossi
Rock your running uni pods and a Factory pro stage one kit? Very cool.....I'm planning on doing the same, but was told by some that a stage 3 is what I should use. Did you use the settings from FP that came with the kit? or did you need anything else.. TIA
Eric M
Config 3 only if it's got pods and an aftermarket exhaust. However, if you get the Config 3 kit, it comes with all the jets in the Cinfig 1 & 2 kits, so you're set for upgrades.
It was perfect right out of the box.
BTW, I'm not actually running Unis - they're individual pods I got from the UK Owners club.
Rossi
Hey Guy's and Dolls.
Just wanted to say thank you for all the input that you have rendered forth. My buddy and I had thought of some of the mentioned ideas and wanted a second opinion. We were happy to see we were all thinking along the same lines. We are going to do the fuel level check and we are also going to look at needle settings. Adjusting back from 3.5 turns to say 2.5 and go from there with adjustments. Thanks again for all the input it was a great help.
I would like to throw this one out for any new-bees. I had a floating tack problem and intermittent power loss. I tracked it down to one of the primary leads on coil 2/3, (this is where the tack picks up its signal power) all but 4 strands of the primary power lead were connected. If I hit a bump the wiring harness would shift and give me enough contact to allow just enough current through to give me my power back and also make the tack run correctly. Hit another bump and the problem was back. Back in 2000 I placed a new connector on the primaries of both new coils. In 8 years time vibration caused the wire to break down at the terminal so lessoned learned and lesson shared. If you have not already check the primary leads and terminals to both coils as a mater of preventative maintenance please do so to keep your self out of a jam in the middle of no where.
Stan K 8)
Orlando
P.S. The Plug wires had not been changed ether. A new set yielded a resistance loss of over half. In other words the new wires have half the resistance of the old wires feeding power to the plug. i.e. more juice to the plug for a hotter bang at the spark.