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SNIPA
07-27-2001, 10:42 AM
There was some talk about choke removal. Does this make a noticable power increase on a stock motor. I have a stock 300ex.
Will this help me? If i do this will i need to rejet?

canadian400ex
07-27-2001, 08:37 PM
I was wondering the same thing! One of my riding buddy's is thinking 'bout doing it to his 300ex.

07-27-2001, 09:05 PM
umm quadfamily said it made a noticeable power increase on his 300

07-28-2001, 11:43 AM
This was a topic on the Connection not too long ago. They all said that there was a power gain. May be worth a try! Although, they were talking about the 400's. But it should work with the 300, as long as they share the same basic design.

kabd69667
07-28-2001, 07:35 PM
i took mine off but i did that while i was putting my pipe on so i'm not really sure if it helped or not
:confused:

quadfamily
07-30-2001, 03:46 PM
It made a big difference on my 300EX which already had some mild mods.

SNIPA
07-31-2001, 11:13 AM
Thanks for the replys. I guess I will go ahead and do this mod. But what about cold starts in the winter....how will this effect?
Will more airflow from this mod require me to rejet?

SNIPA
07-31-2001, 04:58 PM
I have just done the choke removal. I removed the choke plate and while i was at it i left my air box lid off so i could breath more.
Jumped on and there was no gain in power at all. Absolutely no power increase. So i said oh well and put choke plate back on and put the airbox lid back on. Jumped on it again noticed the plate removal and airbox removal actualy made me loose power.

As it sits now stock i can pull the front wheel in first and second. After the mod. i lost torq for some reason. the front wheels stay on the ground. So now i am a little confused as to why? Maybe my stock pipe is holding back the power. The increased airflow made it loose power because i can not get it out? Or maybe it is mandatory for a bigger jet when doing this mod. But one thing is for sure if your 300ex is bone stock this mod will not work. Maybe someone with some more understanding can comment on this.
Thanks,

quadfamily
07-31-2001, 06:24 PM
It was leaving the airbox lid off that made you lose power! This introduces way too much air and causes your engine to run lean. If you're going to take the airbox lid off you NEED to re-jet. It is also my opinion that I need to re-jet after taking my choke plate out. Starting in cold weather will be cured AFTER you increase the pilot jet size probably one size. You should have tried riding your quad with the choke plate out and the lid on. Whenever you increase airflow into OR out of the engine you need to re-jet. You broke the cardinal rule of tuning by making two mods at the same time. You should only change one thing at a time, like for example the choke plate first. I'll bet if you took the choke plate out again and left the airbox lid on you would FEEL the difference. If you're going to remove the airbox lid you will probably need at LEAST 1sizebigger in the main jet, lower the clip on the needle jet and one size bigger on the pilot jet. Again, change one thing at a time and then test it and re-jet for it if needed. Once you've got it straightened out then you can make your next change.

SNIPA
07-31-2001, 07:04 PM
Thanks QUADFAMILY you hit the nail right on the head. Now i realize how sensitive jetting can be. If it is running this good with the stock airbox and factory pipe. I think i'm in for a good suprise when I go bigger on the jets and let this thing breath a little. Thanks for your help...and oh yea...is it easy to change jets? Is there a screw removal or do i have to take the carb completely off to change jets. Jetting is definatley my next step i have to do.

kc 300EX
07-31-2001, 07:37 PM
Dumb question? does doing this leave you without a choke?

DISHO1
07-31-2001, 08:43 PM
Originally posted by kc 300EX
[B]Dumb question? does doing this leave you without a choke? [/
B]



yes, you will need to go up a few sizes on the pilot jet to correct cold weather starting problems

quadfamily
07-31-2001, 10:09 PM
yes, this will leave you without a choke but as was already answered by someone else there will be no problem after you go up a couple of sizes on the pilot jet.

As far as changing jets goes, you need to take the carb off and turn it upside down and remove the fuel bowl to change the pilot jet. You need to remove the top cover and side cover to change the clip setting on the needle jet, BUT you can change the main jet just by removing the big nut on the bottom of the fuel bowl with the carb still on the quad.

Did you try removing the choke plate again with the airbox lid still on?

rydes400ex
08-01-2001, 02:25 PM
whats the stockpilot jet size?

SNIPA
08-09-2001, 07:15 AM
Stock 300ex i have read fron another post.
122 main and 38 pilot.