471 stroker hitting rev limiter way fast - Yamaha YFZ450 Forum : YFZ450, YFZ450R, YFZ450X Forums

silverado2nv · 11-27-2011, 07:25 PM

Ok so I just got a +3mm stroker crank put in... The quad seems to hit the rev limiter super fast... Like at 3/4 throttle in every gear... Mods are venom 14:1 piston nmotion, fci, trail tech stator, stock wheels tires and gears... It's jetted rich for now 210 main needle on 5 clip... So do I need a bigger sprocket or cdi or is this a jetting issue. Thanks again!

dust n' u · 11-27-2011, 08:41 PM

Too rich will make it cut out. You might try leaning out the needle and see if that helps or go to a smaller main.

silverado2nv · 11-28-2011, 09:01 PM

Well I tried a 195... And no change I think it's the rev limiter and not a jet problem... Thinking of a sprocket or a cdi... Any suggestions

YFZ450~BENCE · 11-28-2011, 09:18 PM

it shouldn't hit the limiter very easy in 4th or 5th unless u got no traction. I don't think a sprocket will fix that.

silverado2nv · 11-28-2011, 09:20 PM

well it hits it faster than it used too..clutches feel fine..so Idk what else to do, I actually never hit it in 5th untill now

YFZ450~BENCE · 11-28-2011, 09:20 PM

what else you got done? try a 180 if your Carb isn't bored out

silverado2nv · 11-28-2011, 09:38 PM

mods are nmotion exhuast, fci, venom 14:1, mild port and polish, running vp 110, 195 main 5th clip on nvcq or whatever, @ 3100 ft elevation..I bet the jetting is rich im just trying to take is easy and not lean it out and burn something up ..ive had hell with the head gasket

**Terse** · 11-29-2011, 11:34 AM

If your spark plug is good..... install a new one..... and the coil is not loose on the plug...... then,

I bet the needle needs to be on clip #3 top down.

Dlettie9 · 11-29-2011, 01:12 PM

try turning the fuel screw in a little little bit. Mine used to do that then i leaned it out maybe at the most 1/16 turn and it was perfect again. Another thing, check your float height and make sure its in spec

silverado2nv · 11-29-2011, 03:03 PM

Well I moved the needle from 5th from the top to the 4th from the top... Made a huge difference... No I only have a lil braaap towards the top of the throttle... No deceleration pop or anything... Runs good... I'm just worried I'm to lean... I don't want to mess the engine up... So I might put the a bigger main until I can get it dyno tuned at waynoka

silverado2nv · 11-29-2011, 03:04 PM

I'll post pics of the plugs in a few so you guys can give me some opinions

silverado2nv · 11-29-2011, 05:00 PM

The dark one is with 210 main and needle on 5th notch from top, mid is 195 main needle 4th notch from top..ran alot better, and the other is a new unused plugg for reference....I dont want to be to lean so thats why im worrying.. any input would be nice thanks..

Leo 450yfz · 11-29-2011, 05:19 PM

That middle plug looks good... If you are saying, that there is no popping on decel. I wouldn't worry too much about being too lean. Also, you have to run your engine certain way, to get an acurate spark plug reading on a 450. But with the way your first plug looks, I'd say even Helen Keller would figure, it was rich... no offence meant

Also keep in mind, the bike always runs a little more rich, once it's warmed up all the way, so if you wanted to to, you could try running it with the half choke on, when it's warm. If it runs better then it does now, you can richen it up. I wouldn't worry about it though, if you are not burning up packing faster then usual, or backfiring constantly.

silverado2nv · 11-29-2011, 06:18 PM

I'll get better test once i got to the river... I really couldn't get a good plugg check... I've had bad luck with this quad since i got it... One thing after another some I'm trying to actually get some ride time and not break it this time around!

**Terse** · 11-29-2011, 10:25 PM

When can you dyno in Okie? I know Mike and guys from way back and see em a few times a year.

The high compression and increased stroke will draw more fuel through the jets so your old jets become to rich thus needing to lean them out.

I still think 3rd clip, but what ever works.

The yfz breaks up spits and skips when to rich.....

And plug checks are almost worthless on a yfz. The combustion chamber is very efficient so it doesn't leave much to discolor the plug when jetted right. It will turn a color but not one you are expecting to see. It will look leaner then you think, so people jet them richer and richer till the plug is the color they think it should be when in fact they are pig rich.

silverado2nv · 11-29-2011, 10:57 PM

I don't know when I'll make it up to waynoka... I tried to get a hold of the shop there to check rates ect... So I could plan a trip when I have a day off with some decent weather... All I want is a good tune... Were it will run reliably... I'm not looking to race or get big numbers... I'm tired of fixing this thing lol

**Terse** · 11-29-2011, 11:17 PM

Best bet is a sat on with decent weather this time of year.

silverado2nv · 11-30-2011, 04:26 AM

What's a dyno tune usually run?

silverado2nv · 11-30-2011, 07:20 AM

175 with the mods listed @ 3000 ft???

torcha · 11-30-2011, 07:21 AM

yeah i would have thought a 48 pilot-3rd/4th clip-182/185 main would have been sweet but know nothing of the bike. i had a 210m in my bike and it ripped hard till the mid and soften up and faded, dropped it to a 200 and went like a rocket corners where upon me as soon as i seen them.

11-27-2011, 07:25 PM	#1 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	471 stroker hitting rev limiter way fast Ok so I just got a +3mm stroker crank put in... The quad seems to hit the rev limiter super fast... Like at 3/4 throttle in every gear... Mods are venom 14:1 piston nmotion, fci, trail tech stator, stock wheels tires and gears... It's jetted rich for now 210 main needle on 5 clip... So do I need a bigger sprocket or cdi or is this a jetting issue. Thanks again! __________________

11-27-2011, 08:41 PM	#2 (permalink)
dust n' u Moderator Join Date: May 2006 Location: Portland, OR Posts: 1,304	Too rich will make it cut out. You might try leaning out the needle and see if that helps or go to a smaller main. __________________ 2006 SE-DASA Classic Full System,FCI, Cam mod, Houser +2 stem, Flexx Bars 12* ATV Bend, Fox Floats. Jetting Specs: 48p- 172m-3rd clip NCVQ 2.0 out, 0-500'. 2006 SE yfz450 -Son's-He Thinks "Sorry is for criminals and screw ups and I'm neither"

11-28-2011, 09:01 PM	#3 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	Well I tried a 195... And no change I think it's the rev limiter and not a jet problem... Thinking of a sprocket or a cdi... Any suggestions __________________

11-28-2011, 09:18 PM	#4 (permalink)
YFZ450~BENCE Senior Member Join Date: Nov 2008 Location: Oregon Posts: 936	it shouldn't hit the limiter very easy in 4th or 5th unless u got no traction. I don't think a sprocket will fix that. __________________ 06 yfz450 Barkers Exhaust, Fci intake w/o air box, Mixxer Head, 12:75:1 CP piston, Cam mod, 42mm (sredrum) taper bored carb, matched intake, Rat Stack, Sand tires = 21 12 8, 7 Paddle extremes, Lots of powdered parts.

11-28-2011, 09:20 PM	#5 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	well it hits it faster than it used too..clutches feel fine..so Idk what else to do, I actually never hit it in 5th untill now __________________

11-28-2011, 09:20 PM	#6 (permalink)
YFZ450~BENCE Senior Member Join Date: Nov 2008 Location: Oregon Posts: 936	what else you got done? try a 180 if your Carb isn't bored out __________________ 06 yfz450 Barkers Exhaust, Fci intake w/o air box, Mixxer Head, 12:75:1 CP piston, Cam mod, 42mm (sredrum) taper bored carb, matched intake, Rat Stack, Sand tires = 21 12 8, 7 Paddle extremes, Lots of powdered parts.

11-28-2011, 09:38 PM	#7 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	mods are nmotion exhuast, fci, venom 14:1, mild port and polish, running vp 110, 195 main 5th clip on nvcq or whatever, @ 3100 ft elevation..I bet the jetting is rich im just trying to take is easy and not lean it out and burn something up ..ive had hell with the head gasket __________________

11-29-2011, 11:34 AM	#8 (permalink)
Terse Bad Azz Admin Join Date: Aug 2005 Location: Colorado Springs, CO Posts: 10,127	If your spark plug is good..... install a new one..... and the coil is not loose on the plug...... then, I bet the needle needs to be on clip #3 top down.

11-29-2011, 01:12 PM	#9 (permalink)
Dlettie9 Senior Member Join Date: Nov 2010 Location: Punxsutawney, Pennsylvania Posts: 500	try turning the fuel screw in a little little bit. Mine used to do that then i leaned it out maybe at the most 1/16 turn and it was perfect again. Another thing, check your float height and make sure its in spec __________________ Dylan Lettie #999 2008 XC yfz450 Currently racing in QXC-3 in the AWRCS series and College B in the GNCC series Thanks to my 2012 Sponsors: Renthal, Twin Air, Poly Performance, Pro Armor, Outlaw Racing Products, Hinson Clutches, Leatt Brace, Derisi Racing Support Program, Hiper Technologies, FMF Racing

11-29-2011, 03:03 PM	#10 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	Well I moved the needle from 5th from the top to the 4th from the top... Made a huge difference... No I only have a lil braaap towards the top of the throttle... No deceleration pop or anything... Runs good... I'm just worried I'm to lean... I don't want to mess the engine up... So I might put the a bigger main until I can get it dyno tuned at waynoka __________________

11-29-2011, 03:04 PM	#11 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	I'll post pics of the plugs in a few so you guys can give me some opinions __________________

11-29-2011, 05:00 PM	#12 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	The dark one is with 210 main and needle on 5th notch from top, mid is 195 main needle 4th notch from top..ran alot better, and the other is a new unused plugg for reference....I dont want to be to lean so thats why im worrying.. any input would be nice thanks.. __________________ Last edited by silverado2nv; 11-29-2011 at 05:03 PM.

11-29-2011, 05:19 PM	#13 (permalink)
Leo 450yfz Senior Member Join Date: Jul 2010 Location: NW Indiana Posts: 844	That middle plug looks good... If you are saying, that there is no popping on decel. I wouldn't worry too much about being too lean. Also, you have to run your engine certain way, to get an acurate spark plug reading on a 450. But with the way your first plug looks, I'd say even Helen Keller would figure, it was rich... no offence meant Also keep in mind, the bike always runs a little more rich, once it's warmed up all the way, so if you wanted to to, you could try running it with the half choke on, when it's warm. If it runs better then it does now, you can richen it up. I wouldn't worry about it though, if you are not burning up packing faster then usual, or backfiring constantly. __________________ There is no bandaid for stupidity. Part of the Zbros Racing rider support program. Thank you!!! 2005 yfz450se. Zip tie mod, cam mod, oil mod, FCI, DASA 99db, Dynatech FS CDI, pro flow air box lid, R/D fuel screw. PEP ZPS LT rear, ARS/FX Exit LT MX front end with stem flag, roll design +1.5 stem, precision stabilizer and clamps, LSR +4 axle, CF1 hipers with razor2, hermann racing swinger, DG nerfs. Upcoming winter rebuild: HC piston, head work, MMAD warpspeed cam, carb bore, dyno.

11-29-2011, 06:18 PM	#14 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	I'll get better test once i got to the river... I really couldn't get a good plugg check... I've had bad luck with this quad since i got it... One thing after another some I'm trying to actually get some ride time and not break it this time around! __________________

11-29-2011, 10:25 PM	#15 (permalink)
Terse Bad Azz Admin Join Date: Aug 2005 Location: Colorado Springs, CO Posts: 10,127	When can you dyno in Okie? I know Mike and guys from way back and see em a few times a year. The high compression and increased stroke will draw more fuel through the jets so your old jets become to rich thus needing to lean them out. I still think 3rd clip, but what ever works. The yfz breaks up spits and skips when to rich..... And plug checks are almost worthless on a yfz. The combustion chamber is very efficient so it doesn't leave much to discolor the plug when jetted right. It will turn a color but not one you are expecting to see. It will look leaner then you think, so people jet them richer and richer till the plug is the color they think it should be when in fact they are pig rich.

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11-29-2011, 10:57 PM	#16 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	I don't know when I'll make it up to waynoka... I tried to get a hold of the shop there to check rates ect... So I could plan a trip when I have a day off with some decent weather... All I want is a good tune... Were it will run reliably... I'm not looking to race or get big numbers... I'm tired of fixing this thing lol __________________

11-29-2011, 11:17 PM	#17 (permalink)
Terse Bad Azz Admin Join Date: Aug 2005 Location: Colorado Springs, CO Posts: 10,127	Best bet is a sat on with decent weather this time of year.

11-30-2011, 04:26 AM	#18 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	What's a dyno tune usually run? __________________

11-30-2011, 07:20 AM	#19 (permalink)
silverado2nv Senior Member Join Date: Jan 2011 Posts: 125	175 with the mods listed @ 3000 ft??? __________________

11-30-2011, 07:21 AM	#20 (permalink)
torcha Member Join Date: Sep 2011 Location: Western Australia Posts: 62	yeah i would have thought a 48 pilot-3rd/4th clip-182/185 main would have been sweet but know nothing of the bike. i had a 210m in my bike and it ripped hard till the mid and soften up and faded, dropped it to a 200 and went like a rocket corners where upon me as soon as i seen them.