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soccermike7

I'm confused about some of these WR Free Mods

14 posts in this topic

Hey guys, new to the board. I'm looking at getting a new bike and my first choice is a WR450f (or potentially a Honda crf450x). The more I read it seems as though the honda has more power "out-of-the-box", and everyone talks about how dogged down the WR is in stock form. I am fairly well read on the free mods topics, but I have never done any jetting or anything like that. The below questions, I have found, were never quite answered in the research I have done. So, kind souls out there please help me out.

I have read various review articles on this class of bikes, and also thumperfaq for the mods. Here are my questions.

1. First, I currently have a stock 2002 Suzuki DRZ250. How does a STOCK WR450 compare for speed/acceleration?

2. For an initial mod is there a significant power difference if I JUST have the dealer replace the WR throttle stop with the YZ?

Initially (I think) I just want to do the mods that don't involve changing jets/fuel mixture. So therefore that would require avoiding any airbox mods.

3. Can I remove/replace the factory exhaust baffle without doing the jets? The air/fuel going in would still be the same, but on the way out it would have less resistance. I'm not sure if this matters.

4. Grey wire: I know where it is, and how to do it. Somewhere I read to ride the bike for awhile first. Is this true? Can you do this mod and the throttle stop but NOT do jets/AIS kits?

--if i buy a new WR450f and exchange the throttle stop and unhook the grey wire ONLY, will I have a significant improvement in performance or will I have other issues (like popping on decel).

4. Somewhere it was mentioned to get some kit and have the dealer do the install before picking up the bike. If you were going to have the dealer do stuff to your bike before picking it up, what would it be? I read the carb was hard to get to.

Thanks again for your lasting patience with people new to this bike!:lol:

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Hey guys, new to the board. I'm looking at getting a new bike and my first choice is a WR450f (or potentially a Honda crf450x). The more I read it seems as though the honda has more power "out-of-the-box", and everyone talks about how dogged down the WR is in stock form. I am fairly well read on the free mods topics, but I have never done any jetting or anything like that. The below questions, I have found, were never quite answered in the research I have done. So, kind souls out there please help me out.

I have read various review articles on this class of bikes, and also thumperfaq for the mods. Here are my questions.

1. First, I currently have a stock 2002 Suzuki DRZ250. How does a STOCK WR450 compare for speed/acceleration?

The DRZ is not even in the same league. Even corked up I bet the WR will spit on the DRZ.

2. For an initial mod is there a significant power difference if I JUST have the dealer replace the WR throttle stop with the YZ?

The throttle mod allows the throttle full range. This will make a considerable difference compared to the approx 1/8 in twist with stop in.

Initially (I think) I just want to do the mods that don't involve changing jets/fuel mixture. So therefore that would require avoiding any airbox mods.

I removed the air screen and took the snorkel off the top of airbox, and removed the stock baffle. This required no jetting. The bike actually runs great with stock jetting.

3. Can I remove/replace the factory exhaust baffle without doing the jets? The air/fuel going in would still be the same, but on the way out it would have less resistance. I'm not sure if this matters.

It won't matter. As said above the bike breaths better and the jetting richens up a bit. Hecka lean from the factory.

4. Grey wire: I know where it is, and how to do it. Somewhere I read to ride the bike for awhile first. Is this true? Can you do this mod and the throttle stop but NOT do jets/AIS kits?

I didn't notice anything after doing my grey wire. Supposedly it is really noticeable on the WR250 not so much on the 450.

--if i buy a new WR450f and exchange the throttle stop and unhook the grey wire ONLY, will I have a significant improvement in performance or will I have other issues (like popping on decel).

I might have had some popping on decel but as I recall it subsided with airbox mod and the baffle removed.

4. Somewhere it was mentioned to get some kit and have the dealer do the install before picking up the bike. If you were going to have the dealer do stuff to your bike before picking it up, what would it be? I read the carb was hard to get to.

The throttle stop was kinda PIA to get too. Not impossible but it is hard. You can have them replace the throttle stop and do the grey wire. Everything else is easy.

Thanks again for your lasting patience with people new to this bike!:lol:

You won't regret your decision :worthy:

P.S. I have the WR426 but they are almost the same.

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Hey guys, new to the board. I'm looking at getting a new bike and my first choice is a WR450f (or potentially a Honda crf450x). The more I read it seems as though the honda has more power "out-of-the-box", and everyone talks about how dogged down the WR is in stock form. I am fairly well read on the free mods topics, but I have never done any jetting or anything like that. The below questions, I have found, were never quite answered in the research I have done. So, kind souls out there please help me out.

I have read various review articles on this class of bikes, and also thumperfaq for the mods. Here are my questions.

1. First, I currently have a stock 2002 Suzuki DRZ250. How does a STOCK WR450 compare for speed/acceleration?

2. For an initial mod is there a significant power difference if I JUST have the dealer replace the WR throttle stop with the YZ?

Initially (I think) I just want to do the mods that don't involve changing jets/fuel mixture. So therefore that would require avoiding any airbox mods.

3. Can I remove/replace the factory exhaust baffle without doing the jets? The air/fuel going in would still be the same, but on the way out it would have less resistance. I'm not sure if this matters.

4. Grey wire: I know where it is, and how to do it. Somewhere I read to ride the bike for awhile first. Is this true? Can you do this mod and the throttle stop but NOT do jets/AIS kits?

--if i buy a new WR450f and exchange the throttle stop and unhook the grey wire ONLY, will I have a significant improvement in performance or will I have other issues (like popping on decel).

4. Somewhere it was mentioned to get some kit and have the dealer do the install before picking up the bike. If you were going to have the dealer do stuff to your bike before picking it up, what would it be? I read the carb was hard to get to.

Thanks again for your lasting patience with people new to this bike!:lol:

I'll be totally honest with you. The bikes come jetted VERY lean from the factory, as in borderline lean. Any "mods" you do need to be done along with jetting, otherwise it's pointless to even do it, plus you don't want to run it so lean that it might cause some damage. Even if left stock, the bike could use a good re-jet. Don't hesitate to re-jet, it's not that big of a deal, but unpleasant enough to where you might only want to do it once. If I were you, I'd re-jet, remove the airbox snorkel, remove the exhaust baffle, change throttle stop, disconnect grey wire, JB Weld the AIS, and install a fuel screw. All those things are VERY easy to do, and don't take very long to do. Can easily be done by a beginner in under 2 hours. Don't worry, you wouldn't be the first to do the process, it's nothing too difficult.

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1. First, I currently have a stock 2002 Suzuki DRZ250. How does a STOCK WR450 compare for speed/acceleration?

A stock WR 450f will out acclerate a DR-Z and will have about a 30 mph higher top speed with the throttle stop cut to YZ length. It would not surprise me if the DR-Z had a higher top speed than a WR with the EPA length throttle stop. On the '07+ the throttle stop limits the throttle opening to exactly 1/2

2. For an initial mod is there a significant power difference if I JUST have the dealer replace the WR throttle stop with the YZ?

Initially (I think) I just want to do the mods that don't involve changing jets/fuel mixture. So therefore that would require avoiding any airbox mods.

Its not so much that you're gaining more power' date=' its just that you're able to access it all.

3. Can I remove/replace the factory exhaust baffle without doing the jets? The air/fuel going in would still be the same' date=' but on the way out it would have less resistance. I'm not sure if this matters.[/quote']

3. No. The stock jets are barely enough to work with the airbox and pipe choked up. It carburates cleanly, but even pulling the whole baffle w/o doing the airbox mods will throw the stock jetting out of whack. Assuming the snorkle pulled from the airbox, you generally need to go one step higher on the main(165 from 162 that is stock) with the GTYR or PMB inserts in the stock pipe and two steps higher from stock (168)with a good aftermarket slip on. Alot of people leave the stock pilot jet (45) in there but you have to turn the fuel screw out farther than with the 48. All of this is dependant on temps, atmospheric conditions, and elevation.

4. Grey wire: I know where it is' date=' and how to do it. Somewhere I read to ride the bike for awhile first. Is this true? Can you do this mod and the throttle stop but NOT do jets/AIS kits?[/quote']

It is behind the left side numberplate in the 6 pin connector. Yeah you can do this mod w/o doing the jets and AIS kit.

--if i buy a new WR450f and exchange the throttle stop and unhook the grey wire ONLY' date=' will I have a significant improvement in performance or will I have other issues (like popping on decel). [/quote']

Cut the throttle stop to YZ specs, drill out the black restrictor from the baffle, and cut the gray wire. Thats a good start.

4.... If you were going to have the dealer do stuff to your bike before picking it up' date=' what would it be? I read the carb was hard to get to.[/quote']

Nothing! The last thing I want is some dealer wrench putting their grubby paws on my scoot. I actually had no choice than to do everything in my garage because dealers in Kommiefornia will not touch anything emissions related on EPA regulated motorcycles. The carb is hard to get to but its entirely possible do the main jet, pilot jet, fuel screw install, and o-ring on the accelerator pump linkage without taking the carb out of the bike.

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ok guys thanks for the advice. you said:

"Cut the throttle stop to YZ specs, drill out the black restrictor from the baffle, and cut the gray wire. Thats a good start."

I'm assuming after modifying the baffle you that I will need to rejet, is that correct?

I've heard people comment on the GYTR kit vs a JD kit? I have never jetted before, what should I buy to make it the most seamless?

Most of my riding will be in ohio/wv so not too high of an altitude. I just tried to go to thumperfaq to see if there were any good articles on this, but the site is down (hopefully temporarily!)

I guess I know nothing about this fuel screw thing either. Man its hard to really learn stuff without seeing it in front of me. Maybe that means I need to buy the bike....

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until you get rid of the stock silencer you wont be able to enjoy the performance of the WR. You dont need an expensive aftermarket silencer and head pipe, just a silencer from a YZ will do.In fact I have noticed that there are not too many aftermarket companies that come close to the fit and finish of a OEM YZ pipe.

You will have to rejet, but it not hard to figure out with the pages and pages of info from this site

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Looks like you already got some great advise on this topic. I recently bought the WR450F....I did the AIS kit, air box and exhaust. No jets required! The sub-frame removal is a little intimidating if you are not experienced. Worth the 2 hour effort. No additional tuning was required. My trip to the desert following the mods was SICK! Do this bike, you won't regret it.

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I'm assuming after modifying the baffle you that I will need to rejet, is that correct?

The restrictor in the stock baffle has the inside diameter of a #2 pencil. When the restictor is drilled out the inside diameter is about the size of a regular sharpie...its not that big of a difference. The stock jetting will be fine.

I've heard people comment on the GYTR kit vs a JD kit? I have never jetted before' date=' what should I buy to make it the most seamless?[/quote']

The GTYR kit gives you the smog block off deal and YZ throttle stop as well as the jets. However, the jets are too rich for the bike for most areas. The JD kit is a drop in deal just install it as per the instructions. The price is steep but you're paying for the R&D on needles more than anything.

I have the JD kit and I'm happy w/ it but if I had to do it again I'd just get a 48 pilot jet, 165,168, and 170 main jet, and an '06 YZ needle and be done with it.

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Awesome guys, thanks for all your help and advice. 2 more questions stemming from the above 2 posts:

First: this "YZ silencer" -- is that just an insert into the stock WR that you can put in after drilling out the WR baffle? or do you mean replacing the WR exhaust with the YZ? If you could provide a link to what part you are talking about, I would greatly appreciate it.

Second: I have never replaced jets before: you mentioned just getting the few jets you need and be done with it. That is certainly cheaper than the JD kit: however, since i have never done this before, would it be a good idea to buy it so i have the instructions to go with?

My understanding is that the JD kit is just jets, no AIS removal, no throttle stop. (which both? come with the GYTR kit) -- does the JD kit have anything else?

If i go with the JD kit I'll have to purchase the other AIS removal kit for like $40, right?

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.

First: this "YZ silencer" -- is that just an insert into the stock WR that you can put in after drilling out the WR baffle? or do you mean replacing the WR exhaust with the YZ? If you could provide a link to what part you are talking about, I would greatly appreciate it.

Maxpower is talking about replacing the whole back end of the exhaust system: The aluminium muffler, along with the attached entrance pipe. The last 3' (900mm) or so of the exhaust if you like.

Replacing the tail-pipe (the last little bent bit, inside the muffler) with a bigger diameter one is worth considering.

Lots of discussion on it and other ideas here:

http://www.thumpertalk.com/forum/showthread.php?t=349760&highlight=Modified+Muffler+saves+big+%24%24%24%24

Greg

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All I have done to mine is re-jet with a JD kit (just get the JD kit as the GYTR kit is way too rich)

Cut the throttle stop to YZ legnth.

Opened up the airbox.

Pulled off the exhaust end cap and replaced the exhaust tip with a Pro Moto Billet Performance Insert then put the end cap back on.

Grey wire mod.

I did not even bother to remove the AIS kit as it does not have much effect on performance (you get an occasional popping under full deceleration but that is it)

The bike rips.

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Grey wire, did not notice any difference.

Throttle stop, big difference, more throttle throw.

I just went from stock pipe to a YZ pipe. I did 2 laps around the yard and pulled the plug.

Totally White. Big, Lean difference.

If you do the pipe make sure of jetting. You don't want to run that lean. $$$$$$$$$$$$$$$$$

buff

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Ill throw into the mix here with what I have recently learned off this

site, then trying out.

About a month ago I bought a 2009 WR450F. Said I wasnt going

to do any mods to begin with. I was wrong. The bike sucks in stock form.

So what mods did I do.....

GYTR AIS removal kit, including jets that come in the kit.

Slightly opened air box up, meaning I modified the intake area, but

did not completely removed the snorkel.

I also removed the "plug" at the end of the stock exhaust.

Installed adjustable fuel screw.

So my opinion, however little it may be worth, as a new WR450 owner

and a long time "do my own maint and work" rider.

The bike is awesome now. No need for a new exhaust in my opinion. Im

sure you can get more power out of another exhaust, but you will also

possibly deal with no spark arrestor, and probably be louder too. So the

stock exhaust is fine as long as you drill out the rediculous

reducer plug at the back. The bike has plenty of power now. PLENTY.

The jetting on the GYTR kit is in fact too rich, but the bike is running fine.

I installed an adjustable fuel screw, and have it turned in a bit more than

would be expected. But overall, the bike starts and runs really good.

I did NOT do the grey wire mod. My understanding is that this mod will

cause the bike to "hit" a bit harder. If thats true, then I dont want it.

I like riding tight single track trails, so I like the controlability of the power

as it is now.

Here is some of the different jetting info I put together off this site:

(you will notice several different "recommended" settings. Each of

those were recommended by different members here. So use what you

like)

Stock 2009 WR450F Jets

Air 65

Pilot 45

Main 162

Leak 60

GYTR Kit

Air 110

Pilot 50

Main 175

Leak 45

1. Recommended

Air 110

Pilot 45

Main 165

Leak 45

NFLR Needle (YZ450F)

2004 Specs

Air 65

Pilot 45

Main 165

Leak 60

OBDWR Needle

2. Recommended

Air 65

Pilot 48

Main 168

Leak 60

NFLR Needle (YZ450F)

3. Recommended

Air 65

Pilot 45

Main 162

Leak 60

NFNT Needle (Stock Non Adjustable)

Hope this helps. I spent a lot of time reading on here and trying to

figure out the best way to go about getting what I wanted out of this

bike. So far Im happy with just using the GYTR kit as it came. I have

seen no ill effects as of yet. In my opinion the bike is definitely too

lean in stock form. So any mods will only add to that. I do NOT agree

with the statements made here that you can open the air box and

exhaust, and still not have to do jetting. Jetting is a must in my opinion.

later.:p

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.

I did 2 laps around the yard and pulled the plug.

Totally White. Big, Lean difference.

buff,

No disrespect, but are you sure it wasn't that way before the exhaust?

Unless you have a 10 acre + back yard you would have been riding around on the pilot and maybe the middle needle/needle jet area. It's the main jet that mainly matters as far as seizure-risk goes. ......and twice around the yard isn't really going to change the plug colour anyway I would think.

I could be wrong, but from my experience with 2 stroke roadracers you need to run the bike at high revs (up on tip of the needle/ needle jet and into the main jet area) for a long run in order to get a correct plug reading.

If you want to do it totally right, you should really get it up to revs, run it for a while, then do a "plug chop" (cut the engine off and coast to a stop, no slowing down to an idle.)

Greg

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