Raptor carburetor rejetting, and effects
#12
Bandit, you better qualify that statement or else the anti-raptor guys are going to take that as the Raptor is sluggish! Is it crisp? In 1st or second gear, will it bring the front wheels into the air with just a jab of the throttle and so forth? It's a shame that we have to be so precise, but if not, some of these guys that claim to dislike the Raptor so much, but are always here to read about it, will try to pick everything you say apart and twist it into something bad. wow-that was a long sentence!
#13
Don't get me wrong... It is by no means sluggish... I can sit on top of the gas tank, and it will pull the wheels in the air in second. No clutch...
But thoes who have a car with a 4 barrel QuadraJet carb know what I'm talking about... You're at cruising speed in a car, and when you stomp on it, there is a lag that almost feels like a downshift, them BAM Lottsa power...
It feels like the kinda thing. Say cruising 50% throttle in 3rd, punch it and it has like a tenth of a second lag, then lottsa power. Like a Vaccum Secondary. Except I don't know if these have any type of secondary.
Kinda of a rambling post, but it's hard to explain these things without some sort of comparison.
But thoes who have a car with a 4 barrel QuadraJet carb know what I'm talking about... You're at cruising speed in a car, and when you stomp on it, there is a lag that almost feels like a downshift, them BAM Lottsa power...
It feels like the kinda thing. Say cruising 50% throttle in 3rd, punch it and it has like a tenth of a second lag, then lottsa power. Like a Vaccum Secondary. Except I don't know if these have any type of secondary.
Kinda of a rambling post, but it's hard to explain these things without some sort of comparison.
#14
Now I've seen magazines be wrong MANY, MANY times before so let this be my disclaimer.
I'm quoting from the August issue of 4-Wheel ATV Action...
"Jetting is complicatied slightly on the Raptor, however, because the right carb feeds two of the three intake valves and needs to be jetted richer than the left carb. Yamaha says the clip positions, pilots and needle tapers can remain the same for both carbs, but the main jet in the right carb must always be two sizes larger than on the left."
I'm quoting from the August issue of 4-Wheel ATV Action...
"Jetting is complicatied slightly on the Raptor, however, because the right carb feeds two of the three intake valves and needs to be jetted richer than the left carb. Yamaha says the clip positions, pilots and needle tapers can remain the same for both carbs, but the main jet in the right carb must always be two sizes larger than on the left."
#15
I have that same feeling on my Raptor, but at first I thought it was some sort of super-charge affect that was caused by the air-flow or something. My previous quad, which was a Warrior didn't do such a thing. For me it's kind of like a Banshee when it hits the power-band with a trusting motion.
01 Raptor Blk/White Loving Every minute of it!!!
98 Warrior Blue/Grey
86 Honda TRX 250
01 Raptor Blk/White Loving Every minute of it!!!
98 Warrior Blue/Grey
86 Honda TRX 250
#17
I don't have a Raptor, nor do I know that much about them, but is there throttle linkage on top of both carbs or are they linked in the middle like a street bike, or does just one have the throttle linkage, or is one of them missing something that the other has....hoses etc...?
I don't know just trying to help!
I don't know just trying to help!
#18
I rejetted after removing the spark arrestor and the air box lid front extension. I am at 4100 ft above sea level (80-90 degrees F), and with the factory jetting (140 and 145 mains) I was running rich with the spark arrestor and air box entension on. After removing the parts, the quad was very very lean. I rejetted to a 147.5 and 152.5 but am still slightly lean, and will go to a 150 and 155. The stock pilots are 22.5’s and I went to 25’s but the low end seems rich, so I will go back to the 22.5’s when I go to the 150/155 mains. The needles were at their richest clip position, and I left them there.
To rejet all you have to do is remove the seat and the plastic over the tank and the front radiator cover (plastic with the Raptor decal). You don't need to remove the metal radiator grill that's attached to the front fender assembly. Then loosen the front fender assembly, remove the gas tank and remove the four bolts holding on the carbs. You don't need to take off the throttle or choke cables. The carbs will flip over and rest on the frame rails. It took me 30 minutes to get them to this point and maybe another 20 minutes to reassemble everything. I could do the entire rejet much faster now. Pay close attention to the main jets. I have a few older Mikuni jets that look the same and are the same length, but the Raptor's jets are threaded further down. There is a cylinder that the jet goes into and the jet holds this cylinder down. With my older jets, the jets bottomed out before this cylinder was tight. I don't know if it makes any difference but the cylinders are not tight.(once you see it you will know what I am talking about).
To rejet all you have to do is remove the seat and the plastic over the tank and the front radiator cover (plastic with the Raptor decal). You don't need to remove the metal radiator grill that's attached to the front fender assembly. Then loosen the front fender assembly, remove the gas tank and remove the four bolts holding on the carbs. You don't need to take off the throttle or choke cables. The carbs will flip over and rest on the frame rails. It took me 30 minutes to get them to this point and maybe another 20 minutes to reassemble everything. I could do the entire rejet much faster now. Pay close attention to the main jets. I have a few older Mikuni jets that look the same and are the same length, but the Raptor's jets are threaded further down. There is a cylinder that the jet goes into and the jet holds this cylinder down. With my older jets, the jets bottomed out before this cylinder was tight. I don't know if it makes any difference but the cylinders are not tight.(once you see it you will know what I am talking about).