Hey! Whats up with this?

csdwarf · May 10, 2011

Alright, i've been dirt biking for a long time, from a Xr70 to a ktm 250 exe and everything in between.

I always read people saying WOT, and i know that mean Wide Open Throttle, but i always see posts about people holding there bikes WOT and crap.

Can you guys actually hold your bikes for miles on logging roads? or is WOT an exaggeration some?

now please, don't get me wrong, i love to crack that bad boy open and rip, by no means and i a ferry in my opinion or anyone i had ridden with.

but when i get on a road, i just up shift and cruise, is listening to that crankshaft turn 8-10,000 rpm really fun? peak horsepower is around 7,500 common really! (250 exc)

can the engines really hold up to long runs at WOT, if your properly come down from the HIGH RPM run, and not engine break>lean>seize.

The trails i ride, i would be long gone if i every tried to go WOT for any decent amount of time, so i honestly dont have any experience with the engines and WOT lol.

just was on my mind and figured i might ask :)

thanks guys!

csdwarf · May 10, 2011

Also noticed this on the snowmobile forums, i was trying to get my snowmobiles jetting dialed in, and i was told to go WOT for a 1/4 or w/e.

seems like a good way to trash an engine if everything isn't perfect.

Actually i've seen it happen many times. a great running sled, and at the end of the day, its parts :(

whenever i see this i just want to cry 0_0

thanks :D

julien_d · May 11, 2011

Yes, I use WOT frequently. Remember, this has nothing to do with RPM, only throttle position. Just because you are pinning the throttle during a ride does not mean you are turning max rpm?

csdwarf · May 11, 2011

yeah, i guess i just assumed that WOT meaning down a road.

Now that i think about it I probably do use WOT more then i thought i did before you mentioned that.

just not for a very long period of time, and i might only hit 6500 rpm xD

2-Strokes 4-ever · May 11, 2011

If the trail opens up and there's room, sure.

But... when connecting trails w/ gravel or blacktop, no desire, the extended high RPMs make me cringe (poor motor), having a 2-Stroke sieze on the blacktop can get real ugly IMO. 4-Stroke?... so many more moving parts gives me the creeps too.

EncyclopediaRonnie · May 12, 2011

ill hold a 4 banga wide way longer on a trail than a 2 stroker just the way it feels to me. illl go wide in trails the bits where it sorta dips in the rear and just stick and winds i dunno just seems wrong not to open it up.

i disagree you can stay at wot the whole time up the main rd any motor will die doing this. if theres load on it though in sand or something its different its not at peak rpm with minimal load

rmc_olderthandirt · May 18, 2011

I had a '86 YZ-125 that I would hold WOT a fair amount. Up a hill for sure. Sand wash. Power line roads. I could be ducked down, minimizing wind resistance trying to get more speed.

Then I moved up to a '97 WR250 two stroke. I would definitely open it up all the way, but the only time I would hold it there was if it wasn't in the power band or if I was in a sand wash. I also melted a hole in the piston once doing that.

Now I have a 2007 WR450F. It is rare that I have it WOT and I certainly don't hold it there!

I belong to a club (TWMC) and we race, ride enduros and have a number of organized rides. I am slow, but some of the club members are fast. And their kids are even faster. It is not unusual to be at a race and find one of these kids at the end of a long sand wash with a blown motor. When you look for them in the results they will either be in the top 10 or DNF section.

If you got the skill and the bucks, sure, hold it WOT. If you are going to do that you had better be rebuilding your top end frequently, like every 20 hours of use. If you are like me and push your rebuilds to 100 hours or so then don't be surprised when the piston melts after a relatively short WOT burst.

Rod

csdwarf · May 18, 2011

lol i try to get closer to 100 hours out of a top end, so i shift up...

i do pin it once and a while. normally when under load.

i dont need to rebuild my bike every 20 hours, not worth it to me and far to expensive, I ride every day for hours. so 20 hours is a joke. i get that in a couple weeks if we have a good stretch of weather.

if the kids at the enduros you race blow there bikes up a lot, why don't they gear them up? do the trails really go from that tight to that open?

ecrum28 · May 26, 2011

I think the ability to hold WOT has more to do with jetting than anything else. I'm more familiar with sleds but here's my take. A drag sled you can jet pretty close to meltdown because it only has to last at WOT for 1000 ft. but an oval sled you have to jet a little richer if you want it to last 8 or 10 laps at WOT.

I guess if you plan on holding your bike wide open for long periods you need to jet a little safer (richer) on the top. It might hurt the peak power but at least you won't melt it down.

FNG · May 28, 2011

ecrum28 said:
I think the ability to hold WOT has more to do with jetting than anything else. I'm more familiar with sleds but here's my take. A drag sled you can jet pretty close to meltdown because it only has to last at WOT for 1000 ft. but an oval sled you have to jet a little richer if you want it to last 8 or 10 laps at WOT.

I guess if you plan on holding your bike wide open for long periods you need to jet a little safer (richer) on the top. It might hurt the peak power but at least you won't melt it down.

Stock sleds are jetted for Joe barfly to leave the bar, start it and go WFO across a lake for 2 miles and then do it on the way back to the bar for another beer.

I am 6 sizes down on my mains in my sled and it will survive WFO for 1/4 mile to zero degrees but not much more. Runs better than any 700 I have ever come across and I get 10+ MPG.

As for my dirtbike? I am down 1 on the main and dropped the needle 1 clip. Not much WFO as it has plenty of power before the throttle hits the stopper. In the open I will find my way to 6th gear and lope along. I am an over 40 rider on a 125 so I ride for fun and to keep father-time at bay.

whenfoxforks-ruled · May 29, 2011

On any given day, there is but 1 proper main jet. The one that runs clean, no surge, no blubber. It is THE only jet you can READ the plug. Running a 2 stroke MX engine at wfo is the goal, and more fun if you win. They have rev limiters to keep them from going ballistic. It is not designed to run at max rpm for long, it will over heat, cause pre-mature wear and fail. Jetted wrong, worn already, are but 2 of many reasons for failure. I run mine as fast as it will go, then what? I back off a tad and cruise, what is the big deal? That is on gravel roads. An MX track, that most was designed for, I very seldom hit peak rpm, much less wfo, except for the start. What is left at the end of the power band? Nothing, so why go there? Older and getting back into MX, I lug the motor a lot, but try to keep it in the meat of the power band. I like it right in the middle, just enough pull, yet not loading the engine up. A good motor should last 30 minutes plus 2 laps, at WFO. Then you need a rebuild. Vintage Bob

csdwarf · May 29, 2011

I never really though about it that way, but sleds are very rich from the factory, because of people + lakes.

still see a lot of them blow though, kind of to bad :'( i hate seeing engines go boom

__________________________________________________

You said a good motor should last 30min and 2 laps before a rebuild.

how long do the 4 strokes last? that's a lot of rebuilds, every 30 mins 0_0

how can a 4 stroke be more expensive?

whenfoxforks-ruled · May 29, 2011

More high wear items to replace? 2 stroke exhaust valves wear also. Why would there be any difference between a thumper or smoker? They are both engineered for the same purpose. A 250f against a 250r, would be more expensive? I do not believe by much. They for sure cost more to fix!

Hey! Whats up with this?

csdwarf

csdwarf

julien_d

csdwarf

2-Strokes 4-ever

EncyclopediaRonnie

rmc_olderthandirt

csdwarf

ecrum28

FNG

whenfoxforks-ruled

Old MX Racer

csdwarf

whenfoxforks-ruled

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