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best performance upgrade bang for buck

25K views 28 replies 14 participants last post by  fugitive47 
#1 ·
What I'm looking for is a little advice on performance improvements, but I'm not interested in having to tweak every change of season. My 2009 TW resides at about 2500 - 4000 ft altitude... in the Appalachian mountains. Purchased in South Carolina. I have the stock jetting, which I think is #125... is this correct #? What I find is that the bike takes long to warm up, maybe indicating lean mixture. I've read about the "popping" during decel indicating a lean mixture, but higher altitude provides richer mixture. I'm just a little confused. Anyone have any advice based on my altitude? Should I try going richer with #128? Is an exhaust change worth doing? I've read qwerty's post on carb tuning, just needing some clarification and personal guidance if anyone has two cents to offer. I'm not looking to make the bike into something beyond its intended purposes, just get the most out of the 196cc, but also don't want to compromise fuel economy.
 
#2 ·
2 cents worth...



Go with a 128 or 130 main jet and 3 to 5 .01" shims under the main needle. Best bang for the buck.



I ride in western NC from 1,500 to 5,000 feet altitude. I have tried both the 128 and the 130 and cannot notice any measurable difference. (using a 128 currently).



Be sure to open the slow speed pilot jet screw 2.5 turns, then tune from there.



jb



EDIT: I changed back to a 130 main jet... yes, I can tell the difference.
 
#4 ·
#6 ·
Sean, the information posted here is a pretty good general guideline, but you're going to have to do the work and physically put eyeballs on your jets.



I've seen numerous Cali bikes with the 49-state jetting and vice-versa, for example. No point ordering a 128 if you already have one, or jumping from a 125 to a 130 if you don't. Assume nuttin'.



So few TW's actually run as they should when stock, then their owners further magnify the problem by piling on "upgrades". My .02 is to get yours dialed in 100% stock so you'll have a basis by which to judge future changes.
 
#7 ·
I have thought about swapping carbs on my bike. I have a 98 and an 07. The older carb on the 98 has alot more low end power or "throttle response" the power is still there on the newer carbed bike but it doesnt come on till higher in the rpm range. I can tell a big difference in gravel or while climbing a hill at low rpm then getting on the throttle. In gravel if i nail the throttle in first or second the older bike will actually spin the tire a bit or even get the rear out a little but the other doesnt. I dont know if others have noticed this or just me but it might be hard to tell unless you ride them back to back.
 
#8 ·
I found an iridium plug (about US$15) to be a surprisingly positive investment. I knew they were the ducks nuts for 2 strokes (less fouling) but I didn't realize how much they can help a four stroke become more stable, slightly more responsive and less prone to cut outs in traffic.
 
#10 ·
I vote for jetting and carb adjustments. Once I got the bikes re jetted and tuned right, I didn't feel like I needed to do much else. It changed the way they ride on the road by a large measure. Huge really; tamed and cooled down the 'wild beast'. Since then, keeping everything running nice and smooth has been cheap and easy - Staying on top of the maintenance, basic adjustments, especially the chain adjustment, since I'm still running my stock chain. I'm down near sea level, but I like to go up hills, so I've played with the stock #126, a 128 & a130... #130 works best all around for me. I was up round 8000' last summer and probably would have done better with a lower number, but I stayed with the 130 and was fine. General assessment: Lean is not good on these bikes.
 
#13 ·
I rejetted mine and didn't notice much of a difference until I pulled the snorkel out of the air box. got it out pretty easy by latching on to it with some vice grips and twisting it in one direction till it popped out. just put a new dg o series slip on pipe and it's running (and sounding) even better
 
#16 ·
Always check cost including shipping when ordering from anywhere. I've had local dealers order parts, then add shipping and sales tax on the shipping. Such crooks can easily turn a $5 main jet into a $35 part.



I order from stadiumyamaha.com, then have a friend pick up the parts and drop them in a Priority Mail pack.



Tekei carbs in TW200s have come stock with 125, 126, 128, and 132 main jets, depending on market and year. I've not run a 126, but have all the others.



132 = low altitude and high temps.

130 = best all-around jet for a stock TW200 under 5000 feet altitude.

128 = best all-around jet 4000-9000 feet altitude.

125 = best all around jet 7000+ altitude, still runs slightly rich at 14,000 feet.



Set the pilot and needle height at 75*F ambient temperature and it will be close enough in winter and summer.
 
#18 ·
Thanks all for the feedback. I took the carb off and apart to access the required parts. The TK carb has a 126 main jet. Going to order the shims and 130 main jet, do the pilot adjustment and slap it all back together when I get back that way (I live in Cary NC and keep the bike in Hendersonville NC). Can't wait to feel the results. I will report back.
 
#26 ·
I haven't gotten the new new #130 jet yet (yes, the double "new" is intentional). I'm awaiting the second jet I ordered based on a part number in one of Qwerty's posts. I'll have it in a couple of days. I did get everything else done though, including raising the needle jet spacing with washers and resetting the jet screw just under 2.5 turns. Wow, what a difference! I started it up and there is no bogging down when the throttle is rolled a little and the bike is not yet warmed up. The power and throttle response is noticeably enhanced. Its a different bike. It makes me wonder why it was built the way it was in the first place. It seems like such a waste of good performance. I think I know why the guy wanted to sell the thing... but if he had the bike I have now I doubt he would have.
 
#27 ·
Amazing, right? I guess just tuned lean for emission control stuff as has been noted.



Sorry for the late reply on this, but as for the Jet's R Us jets I put on our 05 & 10, they speced out perfectly and fit properly in every respect. The one difference was instead of a nut on top to secure them, there was a slot for a screwdriver.
 
#28 ·
You know, the jet I received from Jets R Us may have worked, it just didn't look right and I couldn't make myself use it. The new new #130 jet I just got from PartsPak.com is yamaha part number 288-14343-65-00 and is designed just like my stock #126. Gonna slap it in tomorrow and ride like the wind. This is definitely the best mod for the money. Time for a new thread now... "what's the NEXT best performance mod for the money?" ... jk, I'm done for a while, I think.
 
#29 ·
Re: rejeting.... I replaced my OEM TK main jet with a #130 from an old Mikuni. Yeah they look different but they screwed together just fine and all the matters is the size.... of the opening. Interestingly enough after the jet change and adding the .030 spacer on the needle the engine did "sound stronger" when started and there was no more hesitation. However at wide open throttle in 5th it didn't seem as strong. Before the swap the engine would pull strongly until 60mph, then just sort of wind out. Now the "winding out" started at 55mph. I'm at sea level and weigh 200#. After riding about 200 miles with the mod I removed the spacer. The top end performance has returned and the hesitation is still gone. Only 700 miles on the clock and it is a '06 model with no other intake/exhaust mods. Haven't noticed any measurable change in gas mileage so far. Just my experience.....love this forum
 
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