has anyone proved that removing choke does anything?

[cals400ex]

i honestly think that i lost top end pull with the choke removed. i read articles all the time where bikes get cheap port jobs and lose speed. i know a cheap port job is not recommended. i am wondering if this is somewhat the case when removeing the choke. when i read, "bigger ports = loss of power," it makes me wonder if i should put this thing back in. i changed jetting numerous times and still don't have the pull up top that it should have. i know everyone claims that removing the choke give throttle response and a little power but i did it and think it is a line of crap. i basically just want to know if anyone raced a friend before and after removing the choke to see if any gains or loss of power were there. sorry if you disagree, i am thinking really hard about putting it back in. it would probally be back in if i did not have to take the carb off again. what does everyone think?

[ewalker302]

I was wondering the same thing, I started this thread earlier, but I'm still debating if it's worth trying??

http://www.exriders.com/vbb/showthread.php?s=&threadid=69164&highlight=choke


:bandit:

[honda416exman]

Well I don't have a 400 but I did have a 300 and when I did it, it gave me better throtle response and it pulled more to top out the gears.

just my .02

[BigThumper33]

my fcr39 mm I got has a much larger opening....and gave a huge performance increase... I don't see how making the inlet bigger would reduce power. That is just more air going into the motor.

I pulled my choke on my stock carb when I did other mods. I can't say what it did alone because I did several other things at the same time, but I don't think I lost power in any way.

[cals400ex]

yeah, i am not sure but i think it is a waste of time. i don't have any data to back that up with, just a seat of the pants drive. maybe someone can enlighten us?

[RED121572]

Ive been always a little leary about removing the choke. I dismantled my carb for a clean up last month. I went ahead and removed the choke. With that, I started running my it without the airbox lid. With those two little mods, I was able to go up a size main jet and gain some pull that I can feel. Im happy with the results.

[cals400ex]

i may put mine back in. i know my friend is beating me right now and he has a big gun slip on and i have a sparks x-6. there is no way his pipe can match mine. he also has a timing advance key and i am not. he is running a K&N with the lid in place and i am running a uni with no lid. my bike has been jetted numerous times and he still beats me up top and i even put on a 16 tooth front sprocket without any success. valves are adjusted on both bikes correctly. the only thing i can think of is the removed choke. unless that key makes a difference on top end too? i don't know what to think but different things always run through my mind.

[stock400ex]

there is a write up about it in the tech forum. :)

[tprender]

If you have a stock engine you should not have enought engine to pull the 16T sprocket. That is why you have no topend if you have a stock engine. Put the 15T back on and see what it runs like. The choke removed will only affect the pilot jetting at start up from what I have been told. If the 400 was jetted correct before. Then all that is needed when taking off the choke is to go up one size on the pilot. This gives it more air when starting without the choke in the carb.

[4TraxRider]

I took mine out and didn't notice anything really.:ermm:

[cals400ex]

some may not belive me here but i did gain from the 16 tooth in a drag race. it gave a little top end. through the gears it made no difference which sprocket i had on. i was just as fast through the gears with the 16 as i was with the 15. i hear many people on here say put on a 14 tooth sprocket for a drag. i totally disagree with that. my friend put on a 14 tooth sprocket when i had my 16 tooth on. at this time i did not have my pipe and he did. i was already passed him by the end of 3rd gear. if it is a really really short drag, then the 14 might come to an advantage. if you can get into 4th gear in the drag, there is no way i would put one on. the only way i suggest a smaller front sprocket is if your only on a track, tight trails, or just interested in low end power. on a track or out of a turn, the bigger front sprocket does suffer a bit.

i already had a 42 pilot in when the choke was still installed. now after i got my sparks pipe, i put in a 45 pilot.

[tprender]

What is the main jet at? It should be 155 or 157 and 160 max with a stock engine and exhaust. 45 on the pilot is good.
When I had a stock engine I used the 15T and now that I have a 440 I run a 16T being that it is still pulling on the top end. If the ground is a little bit soft the stock engine will not pull topend with a 16T up front. Put the 15 back on and see if it will pull better on the top with out the choke.