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Discussion Starter #1
Hey guys,

This post is all about any questions ppl may have regarding the infamous 130 main jet.
I personally am just now looking for a 130 main jet.

I am also wondering what a "large round" vs "small round" is or if it even applies. I read a post where someone talked about his 130 main jet and specified that it was a large round. What does that mean?

Any info on where to grab a 130 main jet for the TK mv28 carb would be great. :) (2013 TW)
 

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You can purchase the jet from any Yamaha dealer or online OEM parts vendor.

Prices will vary.




Whenever you change a jet, you will need to re-tune your carb by adjusting the pilot screw.

Jb
 

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what exactly do you change the main jet for ? is it to give it more pep? or to adjust for altitude? Thanks
The TW carbs are set lean from the factory.

A larger main jet, along with adjusting the pilot screw, will reduce surging, allow your engine to run a bit cooler, and perhaps give a slight boost in performance.

For high altitudes, the stock jet is fine.

jb
 

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The TW carbs are set lean from the factory.

A larger main jet, along with adjusting the pilot screw, will reduce surging, allow your engine to run a bit cooler, and perhaps give a slight boost in performance.

For high altitudes, the stock jet is fine.


jb

what is considered high altitudes? im in pgh pa? is stock good for me or no? how exactly do you figure if you need a different one? im carb stupid never worked on one before or had one apart, so this is all new to me thanks in advance
 

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3, 000 ft above sea level Qualifies as high elevation.I think. If not sure of elevation of your town. You can google it OR use it as a perfect reason to ride the dub to go check out the city limit sign in your town. Usually has elevation posted somewhere along with the population.any reason is a good reason for me to ride.
Johnny fell in a well? Lets ride!.
Hoss is stuck up on the ridge surrounded by rattlers..Lets ride!
Walmart bullet supply just replenished ? Lets ride!
Gotta drop a duece!! RIDE RIDE RIDE!!!!!
 

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what is considered high altitudes? im in pgh pa? is stock good for me or no? how exactly do you figure if you need a different one? im carb stupid never worked on one before or had one apart, so this is all new to me thanks in advance
My aeronautical chart says the elevation of the airport runways is 1,252 feet...close enough to sea level for me.

You can determine if your bike needs rejetting by how it runs.

If it accelerates smoothly from idle to wide open throttle, with no hesitations, and if it doesn't surge at a steady throttle opening, your carb is set right.

Spend some time reading the Technical Writeups on carb tuning, and look at the photos of the carb internals.

However, there are other conditions that may make your bike run poorly...valve clearances, compression, electrical problems, vacuum leaks....

jb
 

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it says our elevation is at the high end 1,370 and the low end 710. so im good and i dont notice no surging and its seems to accelerate fine for a small thumper :D thanks for all the replys
 

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I rode mine with a 130 main jet and one washer under the needle up to 6,000' on and around the blue ridge pkwy and it did fine. I put the stock 126 back in it for my Utah trip but left the needle shimmed and it did fine up 9,600'. It studdered a bit under higher rpm about 8,000' but ran fine. I left it with the 126 in it when i got back home and it starts easy and doesnt take 5min for it to warm up like it used to. The shim and idle/air mixture helped.
 

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The jet thread on our sister site TK carb Main jet, needle spacing change well written by goldenhtr



The jet is available everywhere, even amazon.com has one Just google the part number, jbfla gave it to you in post #2

Capture.JPG


If you want to find needle spacers then head over to this thread http://tw200forum.com/forum/technical-help/3745-please-show-shims-i-need.html#entry36979

If all else fails read Qwerty's carb tuning thread http://tw200forum.com/forum/technical-write-ups/591-carb-tuning.html it's got lots of Yamaha part numbers



 

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Discussion Starter #13
I was having a hard time finding the 130 main jet at a few different Yamaha dealership sites, but luckily Jbfla had posted that pic :)

I typed in the part number and bam there it was.

Guess I should have tried that right off.

Woot
 

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Discussion Starter #14
Sweet. My new main jet is on its way. I will let you guys know how my bikes runs after I install the jet.

The jet just turns in hard correct? Well not hard i suppose, but seats all the way down.

Anyways will post later:)
 

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Discussion Starter #16
My 130 main jet has arrived. I installed it and just ran its own the street. Definite power gains, starts much easier, quicker throttle response. Less pinging and much smoother power. A fantastic upgrade. This is my testimony to the larger 130 main jet.
 

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Okay So I want to start getting ready to Rejet my carb.

Right now The absolute highest elevation I would get to is about 1,200 feet. I'm spending a lot of time in Toronto (250 ft.) and Guelph (1000 ft.). I;m also going to get an FMF exhaust.

I think the 130 main jet would work well with my elevation. I was curious if anyone else had a similair set up, new exhaust and low elevation that could chime in with their carb settings? shims etc.

Thanks,

Braden
 

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First, be careful when taking the carb apart. Use the screwdriver out of the onboard toolkit as those screws are JIS and not phillips! Next, read: http://tw200forum.com/forum/technical-write-ups/591-carb-tuning.html

Go through the steps in that thread to get the results you want . Don't cheat...you didn't buy a bike with EFI. Buy a 128, 130, and 132 and experiment. At least you'll have them all for the future in your toolbox. Everyone wants to jump to the 130. Well, yeah that may be the most popular set up here, but there is no ONE set up that is going to work exactly the same for every single bike everywhere. A 130 might be to rich for you up north in the colder months, ya know? Good luck!
 

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I thought changing the exhaust would kind of balance that out. Wait do you have to go leaner or richer if you put a FMF or DG on?

Sent from my HTC One using Tapatalk 4
 
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