YZ 250 power valve leakage??


11 replies to this topic
  • cookiemonsterMoA

Posted April 11, 2005 - 06:01 AM

#1

I just bought a 2001 YZ 250 2 days ago. This thing is super clean. The guy i bought it from is the origanal owner and he said if he road it 20 times that's a lot (well that's what he claims,LOL). The bike looks like it was taken very good care of it. He also said the top end was never replaced and doesn't need it since he didn't use the bike much. He was asking $3000.00, but he took $2800.00. Well anyway here are my questions:

I took the bike out for a long ride yesterday to start getting use to it. When i came back the there was a really thick oil coming out of the tube coming from the power valve on the left side of the cylinder. It was pretty thick. It kinda looked like when you have a blown head gasket in a car and the oil and coolent mix. So i called a yamaha dealer and they said this is normal Power Valve runoff. So is this really normal or is there something wrong? The guy i bought it off of said the gas it at least 6 months old. It has not been started or ridden in a really long time. But this thing runs GREAT!!!!!!!!!!!!
The manual said to use a fuel mixture of 30:1 is that good? It sounds a little thick to me. I think the guy i got it from said he was using 40:1. What do you all think?
The guy i got it from was a pretty big guy. About 6'3" and about 220 + pounds. I am about 5'10" and around 160 to 165 bounds. When i sit on it i am on my tiptoes. How and what is the best way for me to adjust the suspension for my hight and weight? Can i lower it a little or will that effect the handling? Because it handles good where its at now.
Last thing, He also told me he was running 10psi in the front and 12psi in the rear. I live in AZ and the dirt is really hard but but loose on top. Is this a good PSI or should i just play with it and see?

Sorry for the VERY long post. I hope some of you can help me with this. I will post some pictures of it when i get home from work.
cookiemonster[MoA]

  • CBus660R

Posted April 11, 2005 - 07:06 AM

#2

The power valve probably just needs to be cleaned out. Get the shop manual (not owners manual) for the bike. Cleaning a power valve is routine maintenance. As for the mix ratio, follow the guidlines on the pre-mix bottle. It varies from brand to brand. The specs in the owners manual will match what it says on the bottle of YamaLube. 40:1 is an ok ratio as long as the oil lists it on the bottle (btw, most modern synthetic oils are good at 50:1 for a 250). I would also drain that tank and put some fresh pre-mix in there. On the suspension side, the only thing you probably need to do is adjust the sag and play with the clickers a little. As long as the springs are stock, they are correct for your weight and were soft for the previous owner. As for tire pressure, 12 front and 10 rear are about as soft as you want to go unless you are riding in pure soft terrain without and rocks or roots that would cause a pinch flat. It's easy enough to play with your tire pressures. Just set them a few pounds harder that normal when you start your ride and take a pressure gauge with you. Ride your normal trail section then let a pound or 2 out and re-ride the trail and see if you can tell a difference and whether you liked the change or not.

  • RMXC51

Posted April 11, 2005 - 07:53 AM

#3

Some leakage out the tube is totally normal. Read the manual and set your sag, it tells you how to tune the suspension. Run 32:1 premix ratio. I'd run 13-14psi in the tires.

Remember when this was thumpertalk?

  • RichBaker

Posted April 11, 2005 - 04:05 PM

#4

Spooge is normal..... I run 24:1 in my YZ250. According to Gordon Jennings, he ran dyno tests and got the best power with 24:1. It's all about sealing the rings, with less oil they don't seal as well and power suffers. If you don't know who Gordon is/was(he's dead now), you're probably fairly young and still believe that magazines tell the truth.....
You'll prob'ly need lighter rate springs, or at least back off the pre-load and check static sag as well as "rider" or "race" sag. Should be 10-25mm of static sag when your "race" sag is in spec(~100mm). Less than 10mm, you need a heavier rate, more than 25 and you'll need a lighter rate...
12-13psi should work well for you...

  • cookiemonsterMoA

Posted April 11, 2005 - 07:20 PM

#5

Well thx for the advice. I got some Golden Spectro Premix (because i us to use it many years ago and it seemed to work fine). I drained the trans fluid and it was a light tan color, not to dirty looking at all.When i opened the new trans oil and started to pour it in I noticed it was red like car trans fluid. So I stopped quickly(probably only got a drop in the case) and read the bottle and it was HP Honda Trans Oil 80w/85w. The yamaha book the guy gave me said to use Yamalube 4(10w-30) or SAE 10W-30 type SE motor oil. So my question is should i use the stuff the guy at the dealer gave me or should i chuck it(since its opened and i probably cant return it and it was only $4.62)and get the Yamalube 4(10w-30)?

BTW CBus660R,
I got the Owner's Service Manual. It shows a lot of stuff. So that make a different one then that?

P.S. I have been riding for over 20 years but have not ridden on dirt for about 14 years so sorry for the dome questions.,

cookiemonster[MoA]

  • NAFLASH

Posted April 11, 2005 - 07:46 PM

#6

i think 80w tranny oil is ok i ran it in my cr 125 and it worked just fine, id think 10-30w would be to thin for the tranny but maybe not. if the manual says to run 10-30 then run it, maybe even 20-50, that wouldnt hurt either. also i find that maxima premix is spretty dam good, i beleive the stuff is called maxima castor 927 and it burns really clean.

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  • crazyYammi

Posted April 11, 2005 - 07:55 PM

#7

tranny oil has a different viscocity rating so the numbers are diff for the same thing, 80w gear oil is close to 10-30w regular oil.

Dont worry about the spooge coming out of your power valve. I wouldnt recommend taking it apart unless you want to practice your curse words.

I would spend a month or two getting used to the bike before you start monkying around with the suspension, you will probably get used to it. Unless the guy resprung it for his weight (unlikey considering how much he rode it) it should be set up pretty good for your size. I would ask him if you get the chance.

I would run 12psi - 25psi on the front depending on if you ride in the rocks. Real rocky go to 18psi. Some people like to run it with really low pressure but unless you are at a pro level your just going to flat a tire and taco your rim.

  • cookiemonsterMoA

Posted April 12, 2005 - 05:35 AM

#8

Kewl thx again for some good replies. I just got nervous when i seen the RED colored oil. Just did not look like regular gear oil to me. I guess I'm getting nervous since this thing is in really great shape and i have not owned a dirt bike in a very long time. When i work on my Harley I know what is going in it all the time and whats good to use with it and whats not :naughty: With the dirt bike its all new to me again.

cookiemonster[MoA]

  • cookiemonsterMoA

Posted April 12, 2005 - 06:52 AM

#9

Well i just filled the tranny up and the oil was thicker then i first thought. When i first started to poor it last night it looked a little thin. Thats why i got nerves.LOL I measured the amount then i removed the check bolt and it started to flow out. The books said when it flows out its full and when nothing comes out its low. But should i let it flow out until it stops comming out? If i over filled it , it will still flow out just like if it was at the proper level. How do i relay know if its at the right level or over filled??Sorry for being a pain in the A** :naughty:

  • CBus660R

Posted April 12, 2005 - 07:00 AM

#10

It sounds like you may have the service manual. The service manual for my RM is a full size book with about 150 pages and it shows everything from rebuilding the motor to fully disassembling the foks down to the last nut and bolt. I bought the bike used so I was assuming that the previous owner had bought a seperate service manual since he was a serious racer who worked at a bike shop. An owners manual will be show basic maintenance stuff like how to change the oil, but not get into full blown service stuff that the manufacturer would like you to take to the shop and pay to get done.

  • NAFLASH

Posted April 12, 2005 - 04:24 PM

#11

what i used to do was poor in the oil until it barely came out then put the check bolt back in and poured in just a litle more and you should be good.

  • Yam297

Posted March 19, 2012 - 12:04 PM

#12

I just bought a 2001 YZ 250 2 days ago. This thing is super clean. The guy i bought it from is the origanal owner and he said if he road it 20 times that's a lot (well that's what he claims,LOL). The bike looks like it was taken very good care of it. He also said the top end was never replaced and doesn't need it since he didn't use the bike much. He was asking $3000.00, but he took $2800.00. Well anyway here are my questions:

I took the bike out for a long ride yesterday to start getting use to it. When i came back the there was a really thick oil coming out of the tube coming from the power valve on the left side of the cylinder. It was pretty thick. It kinda looked like when you have a blown head gasket in a car and the oil and coolent mix. So i called a yamaha dealer and they said this is normal Power Valve runoff. So is this really normal or is there something wrong? The guy i bought it off of said the gas it at least 6 months old. It has not been started or ridden in a really long time. But this thing runs GREAT!!!!!!!!!!!!
The manual said to use a fuel mixture of 30:1 is that good? It sounds a little thick to me. I think the guy i got it from said he was using 40:1. What do you all think?
The guy i got it from was a pretty big guy. About 6'3" and about 220 + pounds. I am about 5'10" and around 160 to 165 bounds. When i sit on it i am on my tiptoes. How and what is the best way for me to adjust the suspension for my hight and weight? Can i lower it a little or will that effect the handling? Because it handles good where its at now.
Last thing, He also told me he was running 10psi in the front and 12psi in the rear. I live in AZ and the dirt is really hard but but loose on top. Is this a good PSI or should i just play with it and see?

Sorry for the VERY long post. I hope some of you can help me with this. I will post some pictures of it when i get home from work.
cookiemonster[MoA]

yamalube just use 4 ounces to every gallon





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