Thumper FAQ Upgrades

[2001yz250f]

Can anyone tell me how accurate and true the free upgrades are on this website? If they work, how hard are each to do, could I do them myself? I am pretty mechanically inclined but drilling on my bike makes me nervous.

The link I was given is: [Only registered and activated users can see links. ]


Let me know what you think.

[sndmn2]

Which one do you want to do? Most are explained in pretty good detail.

[2001yz250f]

Well I wouldnt mind trying any of them, just not sure I want to start "hacking" at my bike unless the mods are fairly well proven and trusted by people who have more experience than myself. Anyone out there done any of these mods? What were the results?

Thanks for the help.

[Ranger_450F]

Well not knowing what the 2001 250's had problem s in. Hard to say

I can vough for the BK mod

The 450 Cam mod will work for you as well I believe yours will be a 03 250 cam

Blue wire mod I never did

TPS disconnected works well for the big thumpers and should do the same for you. Just unhook if you don't like the results hook it back up

Fact is Nobody on here is going to intentionally steer you wrong n mods. If they are here and in the archives they work. As to how big a difference it will make for you thats were the debate comes in sometimes. Just make sure you know what you are doing before you start and if you hit a blocking point ask some questions and you will get squared away.

[InvolvedPatriot]

I've done the GB/BK mod and the "JamesNow" mod. Both made a difference in my yz 426's performance.

I've had a problem getting the GB/BK mod adjusted to the perfect spot, however I got it pretty good and have way less bog than stock now.

JamesNow was a simple mod with almost no materials, just a little time and a ruler. Not sure of the actual benifits. I may have more power, but it is hard for me to tell 'cause I did the mod when I first got the bike and was not used to it yet. I've thought about pulling it out just to compare. That is one nice thing about this mod if you don't like it or don't think it does anything, no harm done just pull it out of the throat of your carb.

Both these mods will effect your jetting(lean).

I intend to do the '03 450 cam mod just as soon as I get the money together. There should be some recent write ups on these mods from Ketoman and Cowboy if I'm not mistaken(however I have been away for awhile).

goodluck

[cowboyona426]

Those mods are all tested and true. Try them, you probably won't be disappointed.

[Dirtbikindad393]

Originally posted by 2001yz250f
Can anyone tell me how accurate and true the free upgrades are on this website? If they work, how hard are each to do, could I do them myself? I am pretty mechanically inclined but drilling on my bike makes me nervous.
Let me know what you think.

I can say this if its a mod that is proven and worthy of performing then you will most likely find it here in the Knowledge Base Archive If you don't find it in here and you want to know about make a post about that particular mod you want to know about. There are many saavy veterans of working on motorcycles here and they will not give you bad info or have you drilling or chopping your bike up for no good reason.

Good Luck with what you choose to try on your bike. Don't forget ask questions here before you do anything if your unsure nobody will make you feel stupid for asking here.

[2001yz250f]

Awesome. Thanks for all the comments, makes me more comfortable with trying some of them. I tried the blue wire mod and I might be making it up but it seems a little snappier on the bottom and easier to start.

I would like to try the Jamesnow mod. Is it difficult? Any tips of what to watch out for?

Thanks for all the help, this place is great!