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can you remove a powerband? need to detune a yz85 85. adjustable throttle?

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I got a yz 85 for a kid that doesn't have much experience but at 13 is way to big for the pw80 he had been riding. He wont ride the yz due to a fear of the snappy hit around 3/4 throttle. When i got it it had a warmer plug and a bad tune with no bottom or mid. It has good bottom and mid now. Its fast! is there a way to take out the top end with out ruining the good bottom?

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right wrist control, simple as that. nothing better. just dont crank on it as hard... it wont snap/flip on him more than once I promise that.  gotta learn the hard way what it takes to flip it. we all have!!!   hes 13.  not 5. he can take a spill and some instruction im sure!!  if he wont ride it... craigslist she goes IMO!!  I was already smoking dope and fist fighting by 13... a spill on a little motorbike in a grass field was the least of anyones concerns lmao!!!  I had my face already smashed by concrete and bikes when I was 5... thanks 8" deep manhole.

sounds like it would just be way easier and better to teach him throttle control, and not to be scared of it.

 

I went home at lunch with some friends in grade 8. I was 14 or 15 at the time.  we had a cr80.  I took it out and was showing off, wheelying down the road... I flipped it (ive only ever flipped 2 strokes), landed on my hands and knees, and slid down the pavement.... bye bye skin on the palms of my hands, was nice having ya while it lasted.  it sucked.  I survived, and learned from it!!!  it toughens you up, teaches you something, and gives one hell of a story/memory for all those around!!!  worth it.

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Edited by cdf450
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29 minutes ago, Michael Grappin said:

I got a yz 85 for a kid that doesn't have much experience but at 13 is way to big for the pw80 he had been riding. He wont ride the yz due to a fear of the snappy hit around 3/4 throttle. When i got it it had a warmer plug and a bad tune with no bottom or mid. It has good bottom and mid now. Its fast! is there a way to take out the top end with out ruining the good bottom?

I agree with cdf450 here, at 13 he should have the coordination, motor skills and wherewithal to learn pretty quick. I fairly certain YZ85s don't have adjustable power valves so no there isn't really a way to adjust where the power hit comes in. If hes scared, he can short shift and not pin it until he gets used to the power hit. This is part of learning to ride a dirt bike. If you put a throttle stop on it, hes never going to learn how to ride the bike, you'd only be delaying the learning process. Throttle stops and de tuning bikes is for small children, not teenagers. Not to mention who wants to ride a 2t with no power hit? that would suck. Once he gets used to it, he'll love it. If he doesn't want to learn either buy him a 4t or maybe hes not cut out for dirt bikes.  

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I have a KX100 that had a huge power hit. I've ridden yz 125s that did not have nearly as big a hit. I can see how it can make it difficult for a beginner. I've been riding over 40 years and did not like the hit while riding trails. It was unpredictable. I added a flywheel weight, reed spacer, Boyeson power wing and now the power is smooth.

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A power band is just a 2 strokes happy place. Its when the fuel and air mix just right. you can do a few things to calm the motor down. 1 get a heavier fly wheel. 2 teach your kid that there is nothing to be afraid of, you control the power. 3 throttle stop will help but you will have to set it so low that you will be dealing with fouled plugs a lot. 4 best way is to sell it and get a 4 stroke 110 or 125. 

 

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it can bog no problem without fouling i slow rode if for a while in below freezing temps. he is a stuburn kid who has only a few hours of riding exp. hes a step child. he dont listen to anything you tell em. I told him about throttle control and how the it wont hit in higher gears at lower speeds. just thought there would be a easy fix to get him used to the bike. I HAVE A THOUGHT, i could run a screw into the throttle housing to stop it dead at 1/2. I could charlie horse him and say if he dont ride he will get another but i dont think that will strengthen the bond.  ill post a picture if the throttle works out.

 

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And if i remember correctly, the YZ 85 doesn't have a powervalve like the other 85's, so I would think it doesn't hit as hard as the other options out there.

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and i have thought about selling it and getting a 4 stroke 125 but this bike is too nice and all sorted out and the ttrs i have seen and drz are just not as nice in my area. and others were involved in the purchase and that would be more work. 

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2 minutes ago, johnk408 said:

And if i remember correctly, the YZ 85 doesn't have a powervalve like the other 85's, so I would think it doesn't hit as hard as the other options out there.

the powervalves smooth the power out and give you better bottom. I know where his fear is coming from he rode it around in first gear and it will lift the front wheel on throttle alone. It cooks. He got real scared after he bobbled a corner and grabbed a bunch of throttle. wheelied recovered but brought it back in to the barn. if i can get it limited i bet he will take to it. Two strokes dont need to foul plugs and if they do you are out of tune. many years of water craft use two stroke and are running their oem plugs from the factory 30 years on. 

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I would stay away from a home-made / bro-engineered throttle stop.  Sounds like something that could result in a stuck throttle.

Maybe try a Dirt Tamer?  It eases the first half of the throttle, but does speed up the last half, so maybe that's not what you want ultimately if he's complaining about 3/4 throttle.  He's 13 on a YZ85 though...normally that means there's only two utilized throttle positions.  Closed and wide open.

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I would suggest you trade for a kx85 or kx100.   I just went though this with my 11yr old daughter..   ended up building a kx85 for her with a kx100 jug on it..  Procircuit makes a powervalve for the kx85/100 that tones the hit way down..   Along with flywheel weight, gearing, timing and jetting it's a totally different bike and she loves it on the trails even though she's a bit of timid child....don't get me wrong it does rip:devil: but is very controllable especially compared to a yz85....    We will be moving this engine into a kx100 frame in a year or two...   she was able to transfer from the baby klx110 no problem after she figured out the clutch.... Btw. rekluse makes a nice auto clutch for the kx85/100 as well..:naughty:

Edited by Nevada Al

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Couple other things to try, maybe retard the timing by a couple degrees, and/or drop a tooth or two on the rear sprocket to take some of the torque away from the rear wheel.

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Just tell him you turned it down . Or like said above gear it tall. What they did with 500s back in the day

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1 hour ago, Michael Grappin said:

i know that he will be ripping but needs an hour or to at low rpm to get the feel of how much better the larger tires handle.

 

thats totally fine.  he can start at 10% throttle, then 15, then 25, etc... till he gets comfortable with it. 

 

literally, 30 minutes in an open field or back gravel road (gravel road is nice because itll spin out vs hook up and wheelie/scare him) and hell have it down.  it would take you longer than 30 mins to make up that sketchy throttle stopper. no offense. 

 

my ex gf never was a "biker". never had bikes when they were young, she never drove or had her license till she was 20.  couldnt drive standard, didnt spend any time on 2 wheels growing up, etc...  basically, about the equivalent of a 13 year old. not much experience with vehicles and motors and clutches etc..  I taught her to ride a done up crf450 no problems on a back gravel road in 15 mins.  it can be done.   or like said above.. maybe he just doesnt have any interest. some dont, and you cant force it. 

Edited by cdf450
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 A lot of good - and not so good- suggestions here.  Put them all together - G2 Throttle tamer.  (More progressive throttle application.)  Flywheel weight. (Steahly makes one.)  Bump the timing back a little.  If this doesn't tame it down enough for the lad, he should go back to video games.

BTW - THERE IS NO POWER VALVE ON A YZ85

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8 minutes ago, motoxvet said:

 A lot of good - and not so good- suggestions here.  Put them all together - G2 Throttle tamer.  (More progressive throttle application.)  Flywheel weight. (Steahly makes one.)  Bump the timing back a little.  If this doesn't tame it down enough for the lad, he should go back to video games.

BTW - THERE IS NO POWER VALVE ON A YZ85

 Great advice.

 

1 hour ago, Michael Grappin said:

it can bog no problem without fouling i slow rode if for a while in below freezing temps. he is a stuburn kid who has only a few hours of riding exp. hes a step child. he dont listen to anything you tell em. I told him about throttle control and how the it wont hit in higher gears at lower speeds.

It will still hit in the higher gears, it's just more controllable.  Like others have said take him to a big grass field after trying to explain throttle control again.  If he doesn't want to listen let him find out on his own.  That will teach him about the bikes power and that he should have listened to you.  Sometimes kids have to learn the hard way.  Maybe it will teach him to respect what you say and the bikes power.

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I've read some have used a large flat washer in the headpipe (at the exhaust port joint) to create an exhaust restriction,

who knows it may even add a bit of low end in the process.

 

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