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Do not retard your YZ250 ignition timing!

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I just bought my new 2013 YZ250 this past January. It was a bear to ride in the mud and snow so I started to read this forum about how to tame it.

 

I read that some riders retard the timing so I rotated the stator plate an eight of an inch counter clockwise.

 

I was ready to sell the bike. Absolutley no low end and when it hit it hit like an f'in 50 HP 125!

 

I was messing around with some other mods and decided to move the timing back to stock. Wow! I now have a bike that will lug and drag me up any hill I point it at. Now I'm looking for knarly terrain to tackle!

 

Here's how I tamed the beast but still keep the timing stock:

 

11oz flywheel

G2 throttle tamer (I highly recomend this)

Rekluse EXP 2.0 auto clutch (love or hate them it works awesome on the YZ)

13 tooth countershaft sprocket (13x50 gearing) (this is for knarly technical terrain)

 

She still has a hit but now has great low end power.

 

Side note: I unhooked the neutral switch and now cold startup in neutral has been greatly improved. No more loading up, poping, or knocks from the engine.

 

 

 

 

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Good to experiment. You found the limit to retarding the spark timing. Your assumed stock setting probably is retarded. What happened when you went the other way? Takes 5 minutes to change it.

Edited by numroe

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Numroe,

 

Now you've got me thinking about how far I could advance the timing! But honestly I'm so happy with the current setup that I'm done experimenting with the motor/powerband.

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Your first mistake was not reading enough about setting the timing. You should havr used a dial guage in the spark plug hole and the timing specs listed in several threads on this site.

1/8 of an inch is a pretty drastic change, the dial indicator settings for +/- 1 degree are extremely small changes, and unless you have set a ton before, would be impossible to do by sight alone.

More accuracy would have had much smaller overall results.

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The bike power wise responds extremely well to additional timing.  typically 2-3 degrees advanced over stock runs the best.  That said it doesn't often hold up that way on pump gas.

Not only due to the additional timing - but also the additional power output puts current pump gasses to their limit.

If yuo run a race fueled bike or avgas - 2-3 degrees advanced is the way to go.

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If you actually use the YZ250 as a Motocross bike, the retarded timing is not a bad thing.

 

I like stock timing on tight tracks, and 1-2 degrees retarded for wide open MX tracks.

 

1/8th on the startor was probablly 5 degrees retarded.

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If you actually use the YZ250 as a Motocross bike, the retarded timing is not a bad thing.

 

I like stock timing on tight tracks, and 1-2 degrees retarded for wide open MX tracks.

 

1/8th on the startor was probablly 5 degrees retarded.

he went full retard

Edited by gabe_k
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Agree. Use the right tool for it.

And I would get rid of that hunk of crap FWW, even in tight terrain. No need if you have the Rekluse.

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nedd the right tool, odds are you werent even set to stock timing when you moved it your super accurate 1/8th inch lol.

 

it works, ive done it on a few yz250s

 

1/8th of an inch is not even close to correct.

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I don't care about peak power. I prefer to do laps as quickly as I can. On my mo-betta ported 295 I find that when I advance the spark timing a little there is an obvious boost in mid rpm power but it is narrow and short lived. When I retard the spark I can get a beautiful spread of power allowing me to ride with much less shifting. But if I retard too far the power drops off suddenly at all RPMs. So I adjust it in a small range, for trails where I need tamed down response, to a little more advanced for MX tracks where I love the power spread, because it's easier with the power spread, like riding a 400F, but handling feels lighter than a 250F. Awesome motor. Sounds unreal too.

 

I think that for 95% of riders and 95% of riding conditions, no one needs more peak power from a generally stock YZ250 either.  Broader power is a faster bike.

Edited by numroe
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Runing a FWW and the EXP 2.0, I wondered about the need for the FWW if I had the EXP but found with the FWW helped it hook up a little more in the tight stuff.

I'm a woods guy and steer with the back end and before the FWW and EXP it was too explosive.

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gabe_k,

The only place you could tell a 1 degree retard is in your imagination!

15FDA1A4-5495-4AB2-822C-1F9BFE0EE0EF_zps

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sooo, i have the GYTR fww in the mail...

what is the consensus of retarding timing and using the fww as well.

bike is for SUPER technical single, xtreme enduro type stuff.

i have 14/51 gearing currently, which I am really liking.

 

i plan to just do fww and check to see where the timing is, reset to 0 and see how that goes.

just wondering for any opinions...

 

cheers.

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sooo, i have the GYTR fww in the mail...

what is the consensus of retarding timing and using the fww as well.

bike is for SUPER technical single, xtreme enduro type stuff.

i have 14/51 gearing currently, which I am really liking.

 

i plan to just do fww and check to see where the timing is, reset to 0 and see how that goes.

just wondering for any opinions...

 

cheers.

The GYTR flywheels are great!  And I think 14/51 is the way to go.  I would just do exactly as you plan and go from there - if by "0" you mean the stock setting? 

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sooo, i have the GYTR fww in the mail...

what is the consensus of retarding timing and using the fww as well.

bike is for SUPER technical single, xtreme enduro type stuff.

i have 14/51 gearing currently, which I am really liking.

 

i plan to just do fww and check to see where the timing is, reset to 0 and see how that goes.

just wondering for any opinions...

 

cheers.

I have an 11oz FWW and 1 deg ret timing.

The timing change was to help with problems I was having due to decked cylinder and increased compression but I found that I do enjoy the smooth power delivery that both FWW and timing help with.

Gearing changes with terrain 14/47, 14/49, 14/51

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I have an 11oz FWW and 1 deg ret timing.

The timing change was to help with problems I was having due to decked cylinder and increased compression but I found that I do enjoy the smooth power delivery that both FWW and timing help with.

Gearing changes with terrain 14/47, 14/49, 14/51

So...were you having detonation probs? running race gas? I ask because I'm sorting out a new to me 295 that detos unless it's 50/50 race gas. Gonna check a few things, and was wondering what my timing options might be. Currently rehabbing a dislocated shoulder, slowing me down!

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So...were you having detonation probs? running race gas? I ask because I'm sorting out a new to me 295 that detos unless it's 50/50 race gas. Gonna check a few things, and was wondering what my timing options might be. Currently rehabbing a dislocated shoulder, slowing me down!

I was getting detonation/ dieseling where it wouldn't shut off with kill switch. I was running 91 octane at the time, i retarded the timing which helped but i also started running 50/50 100LL/91 octane and problem solved.

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So...were you having detonation probs? running race gas? I ask because I'm sorting out a new to me 295 that detos unless it's 50/50 race gas. Gonna check a few things, and was wondering what my timing options might be. Currently rehabbing a dislocated shoulder, slowing me down!

I don't know how bad your fuel is, but I'd be thinking of getting correct squish (I have 1.60mm on my 295), then increase the head vol until deto stops using some reasonable spark retard figure (dont ask me the value).

 

I don't know my spark timing figures, but I've adjusted it enough to know the difference by feel. The difference is insane. I have the mo-betta 295. Using Aus 98 fuel (about 95 real octane).   If I'm feeling kind of hero like, and put the timing where it was when stock (about middle on the stator adjustment) then the mid range hit is so brutal I cannot ride the bike properly for more than about 5 minutes. On trails it'd kill me, literally.   If I retard it too much the power drops off quite suddenly, so it feels even weaker than a KTM300EXC. Actually a lot weaker. I'm just stirring the KTM owners. My point is that the timing change makes a massive difference with my mo-betta 295. No need to measure anything in my situation.

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I do concur that the power delivery can change drastically even by a half degree. .004 will make an EG295 feel weak off the bottom and mid but scream at the top even with proper squish. I have it set at .0055 which is a half degree retarded and it feels perfect whereas stock or slightly advanced timing makes it pull too strong off the bottom and sign off sooner on the top end. We have decent fuel up in Canada and I like to use shell 91 octane but sometimes will put 94 in for a race.         

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