Jump to content
Sign in to follow this  

wr250f aftermarket exhaust, jetting?

Recommended Posts

Hello guys,

I just bought the 2013 Yamaha wr250f, it's a brand-new bike even though it's a 2013 model. Anyway, I am looking at aftermarket exhaust for this and I'm not sure what jets to use with a full system. I'll be buying the FMF anodized titanium power core silencer with a FMF titanuim MegaBomb Header Pipe and 1. Will these two work together? 2. What jetting set-up will I need for this combo?

Hopefully I can get my dealer to do the re-jetting, I won't do it simply because I'd avoid the warrenty..but I can do the exhaust myself. I need your guys suggestions ASAP since I'm picking the bike up this saturday. Thank you in advance

- Andrew

Share this post


Link to post
Share on other sites

Why?

Stock pipe makes nearly the same powwer and is quiet.

 

A WR new needs more than jetting. Grey wire, snorkel, throttle stop. I strongly suggest saving your money you would of spent on a loud pipe.

Well I want it to have a smooth sound and I can remove the baffel from a FMF pipe so that's why. I'd like it to be loud! :)

How do I make it louder without breaking the bank? I'm not to worried about money right now, so through out your suggestion on making it louder. Doesn' a aftermarket pipe produce a bit more power? The stock exhaust makes it bottled up and not able to breathe better..what should I do?

You mention a grey wire, snorkel, and a throttle stop..what are those things? haha.

I also saw that the wr250f has a throttle lock on it, how do I remove that?

Share this post


Link to post
Share on other sites

I don't really like the sound of the stock exhaust, it sounds terrible. Sooo a FMF will fix that. Please tell me what a grey wire is, a snorkel (are you talking about a snorkel from the air box, that's not needed unless It's a different thing for the wr250f) , and a throttle stop is...if those things are easy to do then i'll do it myself. One other thing, what jets do I use with a full system kit?

Edited by TrailRunner250

Share this post


Link to post
Share on other sites

Stock muffler has what is often called 'a pea shooter'. Removing it (or opening it) is part of the standard mods done to a WR. Making a bike loud because it sounds better is not something I can condone. No one on TT will suppoort you in a quest for loud. Loud simply is not cool.

 

I suggest you do a search in the WR/YZ 250F forum regarding 'Free Mods'. There are extensive write ups with photos.

 

Jetting is only done to fix a actual problem, not an anticipated one. Getting a divoce because you will be getting married does not make sense either. Learn your bike, find out what you do not like about it and then address those issues,. Do not fix what is not broken.

  • Like 1

Share this post


Link to post
Share on other sites

Stock muffler has what is often called 'a pea shooter'. Removing it (or opening it) is part of the standard mods done to a WR. Making a bike loud because it sounds better is not something I can condone. No one on TT will suppoort you in a quest for loud. Loud simply is not cool.

 

I suggest you do a search in the WR/YZ 250F forum regarding 'Free Mods'. There are extensive write ups with photos.

 

Jetting is only done to fix a actual problem, not an anticipated one. Getting a divoce because you will be getting married does not make sense either. Learn your bike, find out what you do not like about it and then address those issues,. Do not fix what is not broken.

I see what you're saying. I'll look that up and see what it says. Now, will I have to rejet it if I remove the "pea shooter"? An FMF may not be loud but it does have that mean growl to it, and that's what I'm really after. If modding the stock exhaust to do that makes a mean growl then I'll go for that and not buy an FMF exhaust yet.

Share this post


Link to post
Share on other sites

I see what you're saying. I'll look that up and see what it says. Now, will I have to rejet it if I remove the "pea shooter"? An FMF may not be loud but it does have that mean growl to it, and that's what I'm really after. If modding the stock exhaust to do that makes a mean growl then I'll go for that and not buy an FMF exhaust yet.

Will you have to rejet? Maybe. If you are not a jetting pro, the best plan of attack is often a James Dean jet kit.

 

If you want loud, remove the stock muffler baffle. Not smart but, it is your party. Just pulling the baffle will not require a rejet.

 

You must do the throttle stop and if you are capable, the grey wire.

http://www.thumpertalk.com/forum/15-wryz-250f/

Share this post


Link to post
Share on other sites

Will you have to rejet? Maybe. If you are not a jetting pro, the best plan of attack is often a James Dean jet kit.

If you want loud, remove the stock muffler baffle. Not smart but, it is your party. Just pulling the baffle will not require a rejet.

You must do the throttle stop and if you are capable, the grey wire.

http://www.thumpertalk.com/forum/15-wryz-250f/

Yeah I found a thread about the exhaust and jetting:

http://www.thumpertalk.com/topic/1097261-stock-exhaust-modification-on-2013-wr250f/?hl=%2Bfree+%2Bmods#entry11816844

I don't really want loud, besides I orginally planned on buy a yz250f so money is not tight at all and getting a FMF system is really a good option (besides the free mods). I followed your link but it takes me to the forum and not a thread lol I guess I'll have to find it myself. So what is a AIS eleminator mod? I read about it but I didn't know what that meant. After reading over many threads, getting a aftermarket exhaust is a good idea because the stock system makes the bike seem choked up. So is a throttle stop and a grey wire mod the same thing?

I'm sorry I keep asking questions, I'm new to this.

Edited by TrailRunner250

Share this post


Link to post
Share on other sites

Okay so I found out a lot about the free mods I can do and they seem simple enough. I live in Missouri so what should my jetting be, with the FMF and MegaBomb Header?

Main: ?

Pilot: ?

Leak: ?

I read that a AIS mod is really not needed as much, since all it does it bring air into the exhaust, as the thread said. I now know what the grey wire mod is, all I do is pull the grey wire out and secure it with a zip tie..seems simple. The snorkel mod is simply were I drill holes in the air box sort of speak and it allows more air flow. Now I have all of the basic free mods down. Will the JD jetting kit work with a FMF pipe and a MegaBomb header? Isn't the JD kt only for stock exhaust and the AIS gone?

I really need the questions answered becuase I'm getting my bike soon and I want to start working on it right away. I can do the exhaust, grey wire, and snorkel myself..the jetting on the other hand may be harder. Is it that hard to open up a carb and replace the jets? Hopefully the JD kit has instructions and hopefully it works with the FMF set-up I'll have. I don't want to void the warrenty so maybe I should have the dealer rejet the bike so then it's already ready for the exhaust and other mods...what do you think? Am I on the right track?

Also, a waterproof toggle switch isn't needed after unplugging the grey wire right?

How exactly do I remove the throttle stop screw?!?

Mods to be done (so far):

- Grey wire removal

- Snorkel

- Throttle stop (still don't know how to do that)

- JD jetting kit

- (?) AIS removal kit, where do I find these

- FMF exhaust (full system)

If I'm missing anything then please let me know, I have to do these but I have to be very careful do them.

Edited by TrailRunner250

Share this post


Link to post
Share on other sites

178 main

Stock pilot

NYCS needle, clip three

AIS does not afect performance, it unclutters things and take 5 ounces of weight off.

Your warranty is 30 days and any modification may void it, no matter who does it.

 

Trust when I tell you that you are putting the cart before the horse. You are planning to hop up a bike that stock is way faster than you can be for quite a number of years. You'd be much smarter to spend your money on the suspension and maintenance.

  • Like 1

Share this post


Link to post
Share on other sites

Firstly, I believe there is a 30 day warranty so don't get hung up on that. Wait 30 days or not, up to you.

 

Here is a link summarizing the free mods this bike NEEDS to get real punch from he motor.  It is based on pre-'07 but still applies >>

 

http://www.thumperfaq.com/index.htm

 

Here is a link to some details about the '07+ model years. Just some stuff about different locations of things but the "what you need to do and why" have not changed much >>

 

http://www.thumpertalk.com/topic/818819-unofficial-07-wr250f-mods-thread/page-4#entry11329727

 

Lastly, I was in your shoes not long ago ('13 WR250F). To the noob, the "free mods" that virtually everyone does with this bike sound complicated but are in fact rather easy. 

  • Like 1

Share this post


Link to post
Share on other sites

178 main

Stock pilot

NYCS needle, clip three

AIS does not afect performance, it unclutters things and take 5 ounces of weight off.

Your warranty is 30 days and any modification may void it, no matter who does it.

 

Trust when I tell you that you are putting the cart before the horse. You are planning to hop up a bike that stock is way faster than you can be for quite a number of years. You'd be much smarter to spend your money on the suspension and maintenance.

Thank you for the jetting info, does that NYCS needle clip three come with the JD kit?

I'll be buying that kit and need to know, also does a 178 main come with that JD kit?

I don't care if I'm getting to ahead of myself, the bike barely runs stock! It's so clogged up and it barely will breathe...like i said making this perform like a YZF is so cool and do all of these mods can make it almost like a YZF..so you know I'm going for it. I can handle all of the suspension and maintenance....that's just an excuse to not do a new exhaust and other things.

Share this post


Link to post
Share on other sites

Firstly, I believe there is a 30 day warranty so don't get hung up on that. Wait 30 days or not, up to you.

 

Here is a link summarizing the free mods this bike NEEDS to get real punch from he motor.  It is based on pre-'07 but still applies >>

 

http://www.thumperfaq.com/index.htm

 

Here is a link to some details about the '07+ model years. Just some stuff about different locations of things but the "what you need to do and why" have not changed much >>

 

http://www.thumpertalk.com/topic/818819-unofficial-07-wr250f-mods-thread/page-4#entry11329727

 

Lastly, I was in your shoes not long ago ('13 WR250F). To the noob, the "free mods" that virtually everyone does with this bike sound complicated but are in fact rather easy.

Thank you so much for that link, it'll defientlty help me out with mods..even though some of them ae for older models..it'll still pratically work with the 013 model. The only thing I won't attempt to do in a while is the YZF timing, I don't want to screw with that yet..doing these will open her up for sure!

- Grey wire mod

- Snorkel removal mod

- Throttle stop mod (I'll replace this screw with a YZF screw)

- Jetting change

- Full exhaust system change

This will for sure help it out, what is the air cut valve mod? I saw this..but I still don't really understand what to do there..especially because I don't want to mess the carb up by trying to do that. What ever mod I can do I'll do..unless I'm to worried..you know. But I will ride my new bike once and then I'll immediately start working on it. I have money, time, and patience.

Share this post


Link to post
Share on other sites

Thank you for the jetting info, does that NYCS needle clip three come with the JD kit?

I'll be buying that kit and need to know, also does a 178 main come with that JD kit?

I don't care if I'm getting to ahead of myself, the bike barely runs stock! It's so clogged up and it barely will breathe...like i said making this perform like a YZF is so cool and do all of these mods can make it almost like a YZF..so you know I'm going for it. I can handle all of the suspension and maintenance....that's just an excuse to not do a new exhaust and other things.

JD has propietary needles, really the best thing to do if oyu do not know what you are doing. I gave you what jetting I'd do if I were beginning the process. Jetting is not like installing a tire on a car. You hve to know what you are doing and whaen it is right or wrong. Most dealers simply bolt stuff on and unless you pay for it, will not fine tune it.

Get th4 JD kit. Read the intructions 20 times. Get your bike. Read the manual 20 times BEFORE you touch a single screw.

 

Leave the Air cut valve alone. Trust me whn I tell you if you mod without understanding what you are doing, you will trash your bike. odifying 'just because some other guy...' is a fools folly. Only change something to resolve a real problem and not one you heard on the internetz.

  • Like 2

Share this post


Link to post
Share on other sites

JD has propietary needles, really the best thing to do if oyu do not know what you are doing. I gave you what jetting I'd do if I were beginning the process. Jetting is not like installing a tire on a car. You hve to know what you are doing and whaen it is right or wrong. Most dealers simply bolt stuff on and unless you pay for it, will not fine tune it.

Get th4 JD kit. Read the intructions 20 times. Get your bike. Read the manual 20 times BEFORE you touch a single screw.

 

Leave the Air cut valve alone. Trust me whn I tell you if you mod without understanding what you are doing, you will trash your bike. odifying 'just because some other guy...' is a fools folly. Only change something to resolve a real problem and not one you heard on the internetz.

- Well I'll still buy the JD kit and get me a 178 main. Then I'll try to get that NYCA needle. I understand what you're saying about the jetting, if it's to lean (spark plug would be white) then go with a bigger main, if it's to rich (spark plug would be blackish) then go with a smaller main..so I do understand a few things about jetting. So is it worth getting the JD kit for what I'm going to do with my bike (exhaust, snorkel, grey wire, and throttle stop)?

I won't mess with the air cut valve, I'll just do the basic mods that everyone does (mostly everyone):

- Grey wire

- Snorkel removal

- Change the over-sized throttle stop to a YZF throttle screw..then I'll get FULL throttle

- Rejetting (If the JD kit is good then I'll buy that)

Does the JD kit come with everything needed? I found the kit online although it's not very specific of what is ALL included...

Trust me I want this bike running top notch and to not mess it up, I'll follow what you say (besided the exhaust though lol not to be rude).

Share this post


Link to post
Share on other sites

Or....

Do you think I should have my dealer through in a 178 jet and a new needle right off the bat? I wouldn't really know if it'll be to lean or rich so I can't really do that. I'm so damn confused about all of this jetting. I already mentioned the upgrades and mods I'm doing to the bike, I'll rejet it with the JD kit and go from there..I'll check the spark plu to see how she's running and if she's running bad then I'll have to redo my jetting (ugh..rather not do that). Getting to the Jets is actually easier but on a wr250f I'll have to remove the gas tank and the seat to get access to the carb..I know this from reading about it. I just can NOT find anything on what the JD kit includes..unless I'm missing something. I looked up a NYCA needel but I have a feeling that it will come with the JD kit, for 80 bucks that JD kit better be worth the money! I know this will depend on trial and error but I still need to get ALL of the basics down before I even take the seat off of my bike. Like you said, I don't want to mess up my bike for doing cheesy mods..honestly the timing and the air cut vavle is dumb mod, simply becuase if you're gonna do that then why not save your troubles and buy a yz250f..but since I'm new to this that why I didn't get the yz250f as explained in a different thread on the forums.

One last thing, How do I get to the throttle stop?

I looked at it on the FAQ but it's not clear to me, is the throttle stop inside the carb? Ahh great..looks like I'll have to disassemble the carb just to replace that screw but it's needed cuz the throttle is only limited to 3/4 and that's just pitiful! I already have the part number for the YZF screw, I'll replace it with that. As long as I can find the screw then I can do the work to it.

These mods don't seem hard at all, but I have to do all of my research and thinking needed BEFORE I jump into this. Everything should go smoothly after I rejet it and replace the throttle stop..after that everything else is relatively easy (IMO grey wire..easy, snorkel removal...easy, throttle stop...medium, jetting..hard). Once I know what to do I'll stop asking questions and start doing the actual work. All said and done...this bike will be perfect for me!

Share this post


Link to post
Share on other sites

Throttle Stop

5NL-14591-00-00

 

NEEDLE (#NCYS)

5TA-14916-YS-00

 

No need to buy the Yamaha needle if you buy the James Dean kit.

 

 

You need to read more and stop jumping the gun.

Okay, thank you for those part numbers..I had the throttle stop part number written down before but it was the wrong one, lol my mistake. I am starting to understand more and more, the only reason why I've been confused is becuase I've been stressed out with family issues and can't concentrate, I'm sorry about that sir. BTW, yes I am getting the JD kit so I don't have to worry about the OEM needle from Yamaha.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×