2011 GYTR AIS kit questions?

5 replies to this topic
  • ridgerider2006

Posted April 09, 2013 - 05:14 PM


I bought a leftover 2011 wr450 in january and decided to get the ais kit and larger exhaust end before I ever rode the bike. I finally rode last weekend and was satisfied with the power, but I already have the parts so I want to install them anyway. 1st question--Should I wait to finish break in before installing it? 2nd question--The directions show the exhaust restrictor removal but I bought the even larger opening end from GYTR, will the jetting directions still apply? 3rd question--another carb. question! Yes, my pipe would glow red quickly while idling for the 3 1/2 months waiting for warm weather to ride. But when I finally rode it, I noticed the exhaust output gasses were screaming hot! I've had many different machines, 2 stroke, 4 stroke, bikes, atv's, both dirt and street and never noticed something like this. I mean HOT!!!! I've read these run lean out o' the box. Should I stick with what yamaha recommends in this kit, or could I play with the jet needle clip position? yamaha says 4th from top.
Thanks for any help

  • Krannie McKranface

Posted April 09, 2013 - 07:19 PM


The motor needs to be 'un-corked' per the FAQ and Stickys at the top of the forum.
Just follow that info and you will be fine.
If you motor is not broken in, you should not be letting it sit and idle......you need to seat the rings, so you won't get blow-by gasses around the rings. You need to put some pressure behind those rings by putting heavy short-term load on the motor for 10-15 min, full cool down, repeat 2 more times, then change all the fluids. Break-n only lasts 45 min.

Edited by Krannie, April 09, 2013 - 07:20 PM.

  • upnorthbacon

Posted April 09, 2013 - 08:23 PM


I have mine jetted to the AIS specs, I can't remember the needle setting but I think it was a 175 main that came with it. I'm also at a 48 pilot but that's slightly rich feeling when it gets around 75-80 degrees. My GYTR larger muffler insert will be here today. I've done all the free performance mods already and my bike still runs slightly rich with the AIS jets, I'm around 1000ft above sea level. I think the larger endcap will lean out my jetting enough so it will be spot on. I'll repost after I get some seat time with it installed to see how it works. Unfortunately here in northern MI we're supposed to get 7-10" of snow today and it's my only day off this week!

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  • ridgerider2006

Posted April 10, 2013 - 04:14 PM


Thanks guys for the help. Krannie, I didn't just let it idle for hours on end. But I was jonesing to hear my new bike so I would start it here and there. Thats when I noticed the cherry pipe. I read the faqs in this site so I wasn't worried about that until I really rode it and noticed the output gas was stupid hot, and that scared me. I looked thru the pinned jetting forum but couldn't find a 2011 post so I was hoping for a "tip". I will start with the parts that came in the kit and go from there. I think I broke it in O.K. and I will change the oil and filter now.
Again thanks for the help

  • upnorthbacon

Posted April 12, 2013 - 07:56 AM


Haven't had a chance to go for an acutal ride, but put my gytr insert in last night. Rode up and down the road after the bike was warmed up. I had to rejet to a 50 pilot but it's also 35 degrees here right now. I'm running a 170 main and I can't remember what setting I had the needle at. I wasn't getting any popping on decel and it felt fine but I'll have to wait and see for sure once I can ride for a couple hours.

  • dirtbikekid32

Posted April 12, 2013 - 08:09 AM


I put the kit in my bike, also a 2011, and put an 09 YZ 450 pipe on it, seems a tad rich when the temp gets to be around 90 out. Otherwise im very happy with the set up. I live in Pa, elevation around 1300 ft. Its been 2 years for me and I havent had any need to make any changes..


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