Why at high RPM's does my bike seem to bogg down, until I shift to the next higher gear...Could the GREY wire disconnect help?

Thanks,

Alan

Its called the Rev Limiter.

alan,

with the gray wire and throttlestop still in, you have not yet experienced the 250F. seriously, do a search, find the pics/instructions on the gray wire and throttlestop. that info is also documented in Rick's 250F FAQ. the gray wire takes 2 minutes, and the throttle stop takes about 20 minutes more.

here are some pics to get you started on the throttlestop:
http://losdos.dyndns...r-throttlestop/

these "mods" really are easy, trivial in fact, and you'll feel like, well, "hey there's a whole other bike hiding down there!"

jim aka the wrooster
'01 wr250f

Like wrooster says, you'll think you got a brand new bike with those simple, simple mods. I don't know about the '02s but my '01 would go flat in the middle all the way up to near the rev limiter before the power would come back on (and this was with the throttle stop cut). We didn't know about the grey wire yet and a lot of us were pretty stumped about the complete lack of power in the midrange.

Cut that grey wire man!

so what can I do about it? Will the throttle stop and grey wire removal help?

Alan

Definitly cut the grey wire.But not the red one.Kaboom.

Thanks,

Can I just order a 2002 YZF250 Throttle Stop? I dont have to calipers and other tools to accurately cut it... I will tape off the grey wire this w/e. Also, the high end bogging is related to what...the CDI Mapping b/c of the Grey wire???

Thanks again!

Thanks!!! I guess my term boging down is better discribed as lack of power at mid and high.

Alan

If you don't have the tools to grind the throttle stop down to the proper length, just take it out, it will be OK. I don't think the yzf even has a throttle stop screw.

The YZF does have a throttle stop screw, its just shorter. I think you can get away without it for the short term however. THe other thing you can do is go to you local dealer and order the YZF throttle screw. No tools required.

I think you can get away without it for the short term however.

I took my throttle stop out from day 1 - you don't need it, never had any problems! Your throttle stop is already built into the throttle handle on your handle bar! You also have the rev limiter, so you don't need it - don't grind your stock bolt or buy the YZF bolt - did I say you don't need it?! Just remove it and you're done!

teamcox,

> I dont have calipers and other tools to accurately cut it.

you are eventually going to have to get a caliper if you expect
to work on your bike yourself. so check out this link on calipers.

jim aka the wrooster
'01 wr250f

Buy the YZ bolt; Yamaha wouldn't put them on the YZ's if they weren't needed. It does run $14.03 though (part no. 5NL-14591-00-00). I believe there was a thread at one time about not removing the bolt completely, doing so screws up something, the TPS perhaps. My bike was delivered w/o the screw so after finding the thread about not having one I picked one up.

Edit:
This from the earlier post:
I've heard both sides of the story..."do not remove it" and "just take it out you don't need it" But the thing that makes me keep it in is that the dealer claims they got a bulletin stating that having no screw will will mess up the ign. mapping for the TPS.

Wroost,
Why do they (Yamaha) do dum-s *** stuff like that?
Clogging up the WR's.
Is that some stupid Calif requirement?

(This from a Calif native, now free at last in the Deep South)
Thanks,
YZ250F49

Re: Clogging up the WR's

The Federal government has a spec referred to as the "pass-by" noise standard for all "trail" bikes with the TTR's, WR's, and the Honda XR's being the most prolific. This standard is different from the rules used for sound checks at riding areas around the country looking to control noisy four strokes. The "sound check" standard is SAE J-1287, which we here in MI are very familiar with.
In order to meet the federal standard Yamaha takes a race motor and "clogs" it up, and thank goodness they did. The path of least resistance would be to give us a XR400 clone. An old air cooled, low performance powerplant. The reason the difference is so noticable on the WR compared to the other four stroke trail bikes is the WR starts with so much more. Remember, this is the same motor (with a few tweaks) that Chad Reed won the 125 East SX last year with. If Yamaha has to do a few easily reversible things to the WR to make it trail legal, then go for it. The governments happy, and we're happy after switching it back.

Anyway, the stuffed WR requirement is a Federal requirement not aimed at any one state.

dmp437,
Thanks for the info.
YZ250F49

For future reference...The bone heads at my local Yamaha shop give me the wrong spark plug (a colder one). I replaced it with the hotter/correct one and the bike runs fine. To think I payed these guys ;(

Alan

You do need your throttle stop no matter what. If you take it out it can confuse the TPS when the throttle opens too wide, it can also cause the throttle cables or linkage to bind.