I have installed a Yoshimura exhaust, K&N filter, 150 mains, 40 pilots, removed the petcock and ran a straight line from the fuel tank, adjusted the float levels properly and checked them with the tube. Everything looks Ok and lots of fuel flowing from the tank to the carbs.
I get to about 8000 rpm and the engine starts cutting out and back on like it's starving for fuel. The plugs show that it is running lean.
What am I supposed to do now????
Check for air leaks first, or float(s) may be too low.
Wot, DIY jetting don't work like commercial jet kits? :P
You forgot to shim the needle .025-to-.030.''
Oh ya, I did shim the needle to .030
I just removed the airbox with the K&N inside. Now we're talkin.
Lots of power all the way to redline.
Should I use the pods instead of the K&N in the stock airbox?
Quote from: gsdoodOh ya, I did shim the needle to .030
I just removed the airbox with the K&N inside. Now we're talkin.
Lots of power all the way to redline.
Should I use the pods instead of the K&N in the stock airbox?
Hell yes... 150's are for no air box and K&N pod or pods... too many things called pod... the stock airbox and K&N in it 127.5.
Cool.
Srinath.
Quote from: gsdoodI have installed a Yoshimura exhaust, K&N filter, 150 mains, 40 pilots, removed the petcock and ran a straight line from the fuel tank, adjusted the float levels properly and checked them with the tube. Everything looks Ok and lots of fuel flowing from the tank to the carbs.
I get to about 8000 rpm and the engine starts cutting out and back on like it's starving for fuel. The plugs show that it is running lean.
What am I supposed to do now????
Ok that cant be lean, cutting out and feeling like it wont run... is more thanlikely rich, lean just feels like running out of gas... Did you plug test at speed... run to the rpm you ave trouble in... in 6th gear... mening you must be on the road... and hit the kill switch, and clutch in at that rpm. Then pull over and plug check. Lean feels like you are out of gas when accelerating, and surges when holding steady throttle. Rich stumbles when opening throttle and feels soft and like it wants to skip a beat over and over and over at steady throttle.
Cool.
Srinath.
Went for a ride and ran into the same trouble again.
I pulled the float bowls off and raised the floats 1mm. Also found chunks of crud in the bowls, maybe bits of rubber or something rubber like.
Maybe the crud was getting sucked up to the jets and blocking fuel? What do you think?
It's getting dark now, will test more tomorrow.
Thanks for all of the input folks!
Also check the tank petcock if it's exactly in the open position. Have heard of fuel starvation problems with that chicken being slightly misaligned.
Quote from: gsdoodWent for a ride and ran into the same trouble again.
I pulled the float bowls off and raised the floats 1mm. Also found chunks of crud in the bowls, maybe bits of rubber or something rubber like.
Maybe the crud was getting sucked up to the jets and blocking fuel? What do you think?
It's getting dark now, will test more tomorrow.
Thanks for all of the input folks!
Ok That would be bad... :?
Remember this, the main jet sits just off the floor of the float bowl as the carbs are on the bike, so any sediment, is going in the main jet... now the main is the biggest of the jets, and any fine granular stuff will simply end up in the motor... but big chunks of it... will choke up the thing. So what is that rubber, silicone??? or some hose or O ring getting eaten up. Either way its got to get cleaned up and stopped...
Cool.
Srinath.
If you just went for a ride, you now want to reclean your carbs-
I was having the same difficulty after doing a rejet and full exhaust... Couple things- When you put new fuel line in, if it's not cut very clean, pieces of rubber will flake off and flow to the carbs and they can clog jets.
Second- if the new line is cut too long you can starve the bike at wide open throttle runs. Remember, the angles from the tank to the carb and the frame petcock to the carb are different. The tank to the carb is more vertical and when you really hammer the throttle you can suck out the fuel in the "bend" and then have to wait for gravity to feed the fuel back to the bend causing a moment of starvation. I ended up using a bigger fuel line and cut it as short and direct as possible. I also angled the 'T' fuel inlet horizontal ( before I had the inlet pointed down)- and bodaboom no more shuttering.
And if it is a fuel starvation issue- it makes sense that the plugs would be lean-
If you don't understand let me know and I'll try to post some pics.