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too much throttle response

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just wondering if there is a way to tame the throttle response on a 09 yz250.  :jawdrop:

i ride trials terrain on the yz, hardly ever get out of first gear. 40km in 7 hours yesterday for example.

 

currently i have:

retarded the ignition to -2 degrees (may try -3)

14/51 gearing (i need gearing this low for where i ride)

GYTR fww

re-jetted

 

at the moment it feels like the back wheel is directly connected to the throttle.

crack it a tiny bit and revs increase.

this means when riding this tech terrain, when you get slightly off balance or tired, it leads to too much wheel spin and revs.

 

throttle tamer?

richen the jetting to fatten it up a bit??

vortex type ignition???

any other ideas????

 

just seeking opinions on slowing down that low throttle snap.

thanks alot!!!

:thumbsup:

Edited by surfingboyo

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http://www.g2ergo.com/store/g2-dirt-tamer/

 

Another option I've heard works well.

 

Fattening it up or buying a 4 stroke works, but I don't recommend the 4 stroke.

 

I've also seen idles set so low that the bike almost dies then turns on like a light switch, might try tinkering with that.

Edited by jeffdanger

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cheers jeff.

 

4t is not an option.

g2 dirt tamers look the goods, i think it must just be a mx style throttle pull on the yz.

ie. a few mm of twist at the grip = more throttle opening versus enduro bike....?

 

doesnt look as though i can buy a g2 in aus... has to be bought from o/s.

:banghead:

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A progressive throttle cam sounds like a goer for you.

 

The Vortex X10 CDI definitely works!  A friend has one on a 2010 YZ250.

 

You could try retarding your timing a bit more on the stator. But don't get your hopes too high, because go too far and the motor suddenly gets real dull. Maybe that's what you need. But I guess you want more progressive "roll-on torque".

 

Define what you mean by "re-jetted". What did you change and at what elevation do you ride mostly?

 

I ask about your jetting because I found that going richer on the needle clip pos gave me much smoother response at around 1/3 to 2/3 throttle opening. To compensate I went one size leaner on the main, and I also have the leaner #8 slide.

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G2 throttle cam and a trials tire are the ticket. My friend runs the Vee rubber 19" trials tire with good results. If you can't get that, you'll need to find a used 18" wheel. The trials tire will not alter the throttle response of course, but the low pressure makes for a more comfortable ride and it will get better traction instead of jerking and slipping.

Another option is a more restrictive exhaust. I sometimes run a db snorkel, and that definitely softens the throttle response, but I don't think that product is still available. A spark arrestor might have a similar effect.

Richer jetting also helps, but it sounds like you have tried that.

P.S. Are you riding with a finger on the clutch to give a little slippage? A trials tire with a little clutch slippage is pretty much unstoppable!

Edited by rpt50

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There's a lot of good suggestions here and I'd definitely try the G2 throttle tamer and maybe bump the timing a tiny bit farther retarded.  For what you do, the 18 in. wheel would be a good fit too along with a larger tire selection for 18's.  If you're totally into this, a WR gear swap would be icing on the cake.  

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Yeah, I am on the lookout for an 18" second hand wheel. Haven't managed to snare one yet.

G2 throttle tamer, called around today to buy one but no retailers in Australia can get them.

I am still not super happy with the clutch pull. I am using advanced pro perch and the pull isn't consistent. Bit grabby for my liking too.

I went leaner on both the pilot and main. A couple of sizes down on both.

I will go to -3 first, than revert to richer jetting of I need to.

Vortex does sound sweet!

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I have a RM250,which stock is even more of a light switch and ride the same type of terrain. I have a Vortex ignition and have tried the whole retarding the ignition, taming the motor thing and in the end I have found you want to go in the opposite direction. Advance the timing, raise compression, add gnarly pipe, etc, anything you can do to get more low end. RM's have adjustable preload on the PV, so I increase that as well to have the PV open later. By giving lots of strong bottom end you will have the power you need without clutch abuse at low throttle openings and by having a strong bottom, it builds more power early, significantly calming the mid hit. Same idea as a 300, easier to ride because the strong bottom takes that big mid hit away. I never use the traction/ retarded ignition settings on my Vortex anymore, much easier to ride the nasty with full advance and max bottom end.

Add as much weight as you can to the flywheel and run as tall of gearing you possibly can, you'll be surprised how tall of gearing you can pull with a strong bottom and it really helps with traction and throttle control. Jetting a tad rich keeps the throttle response tamed as well.

 

If you get past my struggling before 3:30 the last half of the vid gives you an idea of how a strong bottom end can just tractor around the woods.

 

Edited by tribalbc
  • Like 1

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I didn't mention a gnarly pipe because a lot of guys say it took away TOO MUCH top end but boosted the bottom nicely.  I guess you could condider that too.  At least it's easy to change.  Not cheap but easy.

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I may not be an experienced enough rider but what about port work? I've got work done on my bike by the PO and I have a FMF fatty that chugs pretty well a gear high. I almost know where in the throttle range the pipes gonna come in about any gear. It's def got that snap but it's not crazy to where it's scary or uncontrollable, whiskey throttles or fatigue aside haha.

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My bikes a little different as I have a 295 ported for low to mid power, but I found that I had too much low end power when I was running the gnarly pipe. Traction was an issue with a knobby, and it had almost too much traction with a trials tire. It was a pain to ride in the slow speed stuff where I was on/off the throttle a lot. Finally I ditched the gnarly for a pc2 and put on a 13 oz fww.

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I may not be an experienced enough rider but what about port work? I've got work done on my bike by the PO and I have a FMF fatty that chugs pretty well a gear high. I almost know where in the throttle range the pipes gonna come in about any gear. It's def got that snap but it's not crazy to where it's scary or uncontrollable, whiskey throttles or fatigue aside haha.

i've heard good comments about the Fatty too and if I still need to calm it down, I think I'll try one instead of a gnarly

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i've heard good comments about the Fatty too and if I still need to calm it down, I think I'll try one instead of a gnarly

You've got an early 2000s YZ too don't you? Mines an 01. If we ever get a chance to ride together or hell even meeting up and swapping pipes for a weekend just to see what theyre like, I'd be game for. I've been considering a Gnarly due to the reviews but have enjoyed this Fatty. Haha that sounds funny to say out loud..... Edited by deener

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You've got an early 2000s YZ too don't you? Mines an 01. If we ever get a chance to ride together or hell even meeting up and swapping pipes for a weekend just to see what theyre like, I'd be game for. I've been considering a Gnarly due to the reviews but have enjoyed this Fatty. Haha that sounds funny to say out loud.....

Yup, mines an '01 too.  That's a good idea - to swap them some time for a scientific seat-of-the-pants test.  I have a PC platinum on now - it came with it.

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deener,

 

Fatty has broad and punchy power. Revs build quickly. Great MX pipe for when traction is good.

 

Gnarly has more torque when below the pipe. A more gentle mid hit. And it wont rev as far up top.  You can

 

The PC2 has torque as broad as the Fatty, but it's smoother and more docile power. 

 

My PC2 pipe needs some repairs. I'd like to test it again one day vs the Gnarly. Mainly to see which one puts down the power the best. I'm certain the Gnarly makes more torque down low.

  • Like 1

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As said above:

  1. Flywheel weight
  2. G2 throttle
  3. Drop to 13 tooth front sprocket
  4. Ride in second gear
  5. Low end pipe
  6. Low end porting (optional)
  7. You mentioned leaner jetting - If it's too lean it'll give more snap...

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deener,

Fatty has broad and punchy power. Revs build quickly. Great MX pipe for when traction is good.

Gnarly has more torque when below the pipe. A more gentle mid hit. And it wont rev as far up top. You can

The PC2 has torque as broad as the Fatty, but it's smoother and more docile power.

My PC2 pipe needs some repairs. I'd like to test it again one day vs the Gnarly. Mainly to see which one puts down the power the best. I'm certain the Gnarly makes more torque down low.

Thanks for the info. That's pretty much what I've read about the different pipes out there. I'm really itching to try out a Gnarly just to see what it's like. But at the same time, maybe mix of my port work and the JD kit I've got in, makes for a surprisingly chuggy setup with a pretty smooth transition. My bike does have a bit of snap when I want it but the hits not crazy. When the time comes and I get to try out a Gnarly I'll probably be singing a different tune haha. Haven't ridden much other than my bike and a few stock zingers, so I don't have a lot to really compare to.

Edit*

After rereading the OPs first post I misunderstood what he was looking for. If it's a throttle issue I don't wonder if like mention above, throwing a G2 on there may be worth a shot. Especially since first gear sucks on these bikes hahaha.

Edited by deener

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You need to adjust your gearing so you're not riding in first gear all of the time. That's easily you're best solution.

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