Wheeler 2,530 Posted September 10, 2020 (edited) Well this was a surprise... While the tank is off to replace my boot, I figured I’d ha e a look at my plug.. haven’t pulled it since I put my motor back together months ago.. however it seems to run great. Fires right up, have to move choke while warming up, but then idles great, pulls great, top end feels great.. I did notice other nite while testing the new light bar that the header pipe was “barley” hot even at the engine. Most of my running is mid range with some hard WOT short burps... so I’m thinking the needle may need to be lowered.. after hard accel I get the popped on decel... Considering how it’s really been running this was a surprise.. haha my sig says leaner is meaner.. she ain’t lean! Edited September 10, 2020 by Wheeler Share this post Link to post Share on other sites
Wheeler 2,530 Posted September 10, 2020 So because it "feels" like it's running great, my thoughts are this... humour me... any input appreciated... The pilot is stock 300ex 38 Needle (from memory is 3rd clip) Main is stock 122 or 118 what ever is in a 300ex.. So, I run mainly mid range but hammer it wot for spurts but never hold it there... This leads me to believe I should lower the needle first & try that, see how it runs... Then I'm thinking that my TOP end RPM according to my tiny tack WOT are down.. I'm not at the crazy 8750 I've hit.. I'm more like 7400-7700rpm now.. so that may lead me to believe that's why i'm down.. main needs less fuel.. I've learned over the years, to make one change, run er & see... what you guys think based of that little info... Share this post Link to post Share on other sites
oh400ex 629 Posted September 10, 2020 3 minutes ago, Wheeler said: it "feels" like it's running great IMO all these 300s run better and last longer with a slight rich mixture. Carbon deposits can be removed but wear is forever. That plug is a healthy rich but not a "foul-it-out" rich. My $0.02? Don't touch it. 1 Share this post Link to post Share on other sites
Wheeler 2,530 Posted September 10, 2020 oh400ex... if you only knew me a bit better... !.. I can't have this.. black plugs or slightly carboned plugs are UNACCEPTABLE in my books.. I must make some tweaks & adjustments.. but this time well thought out ones.... 1 1 Share this post Link to post Share on other sites
oh400ex 629 Posted September 10, 2020 Haha I get the mentality but in practice you are likely just shortening the life of the bike. I don't put on performance parts for the same reason. If you want to wrench so bad you could have just got the Robin Blue... 🤣 1 1 Share this post Link to post Share on other sites
SlammedRanger 1,560 Posted September 10, 2020 Do exactly as you were thinking. Lean the needle out one clip and see how it runs after. If its better leave it. Worse go back. You most likely wont have to adjust your main as the needle change is going to make some of that adjustment for you. Since you dont drag race and run wide open throttle real long your main isnt even showing on that plug. And you dont hold it there long enough to come entirely off the needle metering. My .02 3 1 Share this post Link to post Share on other sites
Wheeler 2,530 Posted September 10, 2020 Thanks Slammed... that was my thinking... 1 Share this post Link to post Share on other sites
Wheeler 2,530 Posted September 10, 2020 (edited) The needle is actually on the second one down.. gonna try er on the the top one... see how it goes.. Edited September 10, 2020 by Wheeler 1 Share this post Link to post Share on other sites
Wheeler 2,530 Posted September 10, 2020 (edited) Well boyz... I think that they may have done the trick... I've raised the clip to the top.. I live in the burbs... & took chance with cops & anyone calling them... Just went for rip around the block all over... Pulls harder thats for sure!! & throttle response seemed oh how would I say it... crisper/more responsive...RPM pulled faster too! I definitely didn't make it worse thats for sure!!! I'll run it that way for a while, then pull the plug. I didn't install new one... kept the carboned up one.. Edited September 10, 2020 by Wheeler 7 Share this post Link to post Share on other sites
_Wilson_™ 6,603 Posted September 11, 2020 @Wheeler thanks for the update. sounds like she's running like a bat of h--l again. Share this post Link to post Share on other sites
Misterclean 420 Posted September 12, 2020 Thanks for the update. I'm installing a new carb for my YZ 250 tomorrow. JD Jetting supplied me with extra needles and jets. Guess I will be tuning tomorrow. 1 Share this post Link to post Share on other sites
Wheeler 2,530 Posted September 23, 2020 Well I’m still in bush putting the most amount of miles on the ole girl in a long time!! The needle change was amazing for power!! Here is how she looks after a few tanks of fuel.. same plug! I may play/tweak the pilot & main as well.. lots of backfire/pick/pack on deceleration.. so may need to richen the pilot up.. 3 Share this post Link to post Share on other sites
_Wilson_™ 6,603 Posted September 23, 2020 thanks for the update ... looks like it might need just bit more tweaking ... with popping going on with deceleration did you change out the oem exhaust ?? 1 Share this post Link to post Share on other sites
Wheeler 2,530 Posted January 19, 2021 Lol @_Wilson_™ sorry for the many month late reply.. haha yea the OEM exhaust was changed out to a 300ex full stainless. since this post, I changed the pilot to. 40. Made it a lot worse. Went back down to a 38 & just adjusts the fuel screw. All is good & healthy again!! 2 Share this post Link to post Share on other sites
_Wilson_™ 6,603 Posted January 20, 2021 no problem wheeler ..... thanks for the update. glad you got her back humming again. (thumbs up) 1 Share this post Link to post Share on other sites
Fishfiles 20,148 Posted January 20, 2021 17 hours ago, Wheeler said: yea the OEM exhaust was changed out to a 300ex full stainless. Will a 300 EX exhaust fit from the head back ? Or did you put a 300EX muffler on a 300 Fourtrax pipe ? Share this post Link to post Share on other sites
Wheeler 2,530 Posted January 20, 2021 1 hour ago, Fishfiles said: Will a 300 EX exhaust fit from the head back ? Or did you put a 300EX muffler on a 300 Fourtrax pipe ? full 300ex exhaust system fit. My have make a tweak here or there depending on what year your machine is.. 2 Share this post Link to post Share on other sites