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New to 4 strokes, I have questions!

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I hate to blow up the forum with questions, I typically try to find out the questions myself or answers those I know the answer to. But I recently let go of my 2 smoke love and went to a 2004 YZ250F. The owner before me rode it twice, and the owner before that said to have taken great care of it (And it shows).

Anyways, I'm not a complete noob. I know 4 strokes run non-mixed gas and are more complicated. I know to an extent what the difference is, and so on. But here are my questions.

1.There is an oil retained in the frame, how do I change it? How often should I change it? What is it's purpose?

2.Crankcase oil: Nothing different, right? (Just want to make positive before I mess with it).

3. I bought this bike about 3 hours away, believe it or not the whether there is MUCH different from here, and the elevation changes quiet a bit too. The bike is a little slow at start and backfire before it warms up. Is the air-gas mix off? Does it need to be adjusted? If so, HOW do I adjust it?

Thanks for your time! (For the record, this is also my first Yamaha. If there is anything they do specific, please clarify. Thanks!)

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J, Welcome to the Blue side of the isle. I currently own 3 of these bikes, and really like how they run and ride. 02 YZ250F for my son, 03 YZ250F with mods, and 04 WR250F for winter (has lights).

I’ll answer in order:

  1. Oil in the frame. Yes, the frame is both a reservoir and a cooler. The engine circulates cooling and lubricating fluids, oil and antifreeze, thru the engine. Yamaha uses the same oil to lube the transmission as well…. Not like the Honda system which is separated.
  2. Crankcase oil. Yes/no, but see above. The sump is a dry sump design that keeps the oil away from the crankshaft while the engine is running, and this in turn reduces drag on the crankshaft which increases power.

The plug (12mm) on the front of the frame down tube from the steering stem lets the oil out of the frame only. There is another 12mm plug down by the gearshift on the left side for the sump. There is an oil filter behind a cover on the right side case held by 3 bolts, 2 8mm and one 8mm hex cap screw. There are rubber o-rings that seal the joints that transfer the oil.

The oil capacity is 1.25 qts and should be changed every 5-10 engine operating hours religiously. This is a small amount of oil and the engine is highly stressed, so the polymers in the oil get shredded quickly ( the oil breaks down) and doesn’t protect as well. So we change the oil rather than stretch out the time. Oil is cheaper than parts and labor.

It will generally take about 1.3 to 1.4 qts to bring the oil level up to the top of the stick with a filter change. When you change the oil, you run the motor for about 2-3 min to distribute the oil and pump it up into the frame oil tank. You check the tank level by the dipstick on the left side of the steering stem, you put oil in by the rubber plug on the left side case.

You will also need to service the air filter often, as getting dirt past the filter will ruin the valves, seats, cylinder and piston. The best protection I use is a triple protection, TwinAir filter with a single Flo filter on top of that. I’ve never has dirt get into my engines with that setup, and it didn’t affect jetting. Be sure to use a good air filter oil like Bel-Ray or other, and a filter sealing grease. I do not use single element filters because of bad luck and dust getting thru. While I’m on it, you need to check the valve clearance (or have someone else do it).

Fuel mixture can be adjusted by the fuel screw located under the carb at the front of the bowl. You can use a straight screwdriver bit to adjust it. You need to screw it all the way in lightly, counting the turns. Should be between 1.5 and 3 turns out, probably about 2 turns for you. You can go out to but not more than 3 turns out since it can vibrate out and get lost. Turn out the fuel screw will bring in more fuel and richen up a lean run or popping on deceleration symptom. William1 has the detail setup instruction so search on his ID.

Good luck.

Edited by ronbuell

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J, Welcome to the Blue side of the isle. I currently own 3 of these bikes, and really like how they run and ride. 02 YZ250F for my son, 03 YZ250F with mods, and 04 WR250F for winter (has lights).

I’ll answer in order:

  1. Oil in the frame. Yes, the frame is both a reservoir and a cooler. The engine circulates cooling and lubricating fluids, oil and antifreeze, thru the engine. Yamaha uses the same oil to lube the transmission as well…. Not like the Honda system which is separated.
  2. Crankcase oil. Yes/no, but see above. The sump is a dry sump design that keeps the oil away from the crankshaft while the engine is running, and this in turn reduces drag on the crankshaft which increases power.

The plug (12mm) on the front of the frame down tube from the steering stem lets the oil out of the frame only. There is another 12mm plug down by the gearshift on the left side for the sump. There is an oil filter behind a cover on the right side case held by 3 bolts, 2 8mm and one 8mm hex cap screw. There are rubber o-rings that seal the joints that transfer the oil.

The oil capacity is 1.25 qts and should be changed every 5-10 engine operating hours religiously. This is a small amount of oil and the engine is highly stressed, so the polymers in the oil get shredded quickly ( the oil breaks down) and doesn’t protect as well. So we change the oil rather than stretch out the time. Oil is cheaper than parts and labor.

It will generally take about 1.3 to 1.4 qts to bring the oil level up to the top of the stick with a filter change. When you change the oil, you run the motor for about 2-3 min to distribute the oil and pump it up into the frame oil tank. You check the tank level by the dipstick on the left side of the steering stem, you put oil in by the rubber plug on the left side case.

You will also need to service the air filter often, as getting dirt past the filter will ruin the valves, seats, cylinder and piston. The best protection I use is a triple protection, TwinAir filter with a single Flo filter on top of that. I’ve never has dirt get into my engines with that setup, and it didn’t affect jetting. Be sure to use a good air filter oil like Bel-Ray or other, and a filter sealing grease. I do not use single element filters because of bad luck and dust getting thru. While I’m on it, you need to check the valve clearance (or have someone else do it).

Fuel mixture can be adjusted by the fuel screw located under the carb at the front of the bowl. You can use a straight screwdriver bit to adjust it. You need to screw it all the way in lightly, counting the turns. Should be between 1.5 and 3 turns out, probably about 2 turns for you. You can go out to but not more than 3 turns out since it can vibrate out and get lost. Turn out the fuel screw will bring in more fuel and richen up a lean run or popping on deceleration symptom. William1 has the detail setup instruction so search on his ID.

Good luck.

Thank you so much! Where is the love button?!

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Do you have a manual? it will really help! I can email it to you if you don't have one, just PM me your Email. I have the same year bike.

When I change the oil, I warm up the bike to get the oil into the frame tank, and make it more runny, then I open the bolt on the front of the frame tank (down low). You'll want to have your wheel turned, and a catch pan right there because as soon as you uncork it, warm oil will come squirting out and you don't want it on your wheel. There won't be much in the engine after running it for a few minutes, but you should drain that, too. When I add oil, I usually just go by the manual and measure out the required amount it's easier for me.

I got a SS re-usable filter from Scotts Performance. It has better filtering performance, and I'll never have to buy a new one again. With how often you change the filter, it pays off rather quickly. I clean it off each time I change the oil.

Check valve clearance as described in the manual.

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Do you have a manual? it will really help! I can email it to you if you don't have one, just PM me your Email. I have the same year bike.

When I change the oil, I warm up the bike to get the oil into the frame tank, and make it more runny, then I open the bolt on the front of the frame tank (down low). You'll want to have your wheel turned, and a catch pan right there because as soon as you uncork it, warm oil will come squirting out and you don't want it on your wheel. There won't be much in the engine after running it for a few minutes, but you should drain that, too. When I add oil, I usually just go by the manual and measure out the required amount it's easier for me.

I got a SS re-usable filter from Scotts Performance. It has better filtering performance, and I'll never have to buy a new one again. With how often you change the filter, it pays off rather quickly. I clean it off each time I change the oil.

Check valve clearance as described in the manual.

The whole bike was rebuilt with literally only a couple of hours on it, so I'll check the clearence but I'm gonna wait until next week before I tear it down. Please do send me that manual, it's Jkcollins6695@gmail.com (I don't care if people spam me, spam filter is pretty good about catching it.)

As for the airfilter, it already has a twin air secondary filter (I believe that's what it's called). I cleaned it up and sprayed it with filter treatment, so it's good to go.

I adjusted the carb, it fires right up, idles strong and doesn't backfire or bog a bit!

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Sounds like you got a really good deal then! In that case, checking the clearance would be good, then in another 10 or so hours I would say just so you know when they start walking. I think I've heard a rule of thumb is after shimming them twice, it's time to get new ones because the hard coat on the titanium valve has worn off and they'll keep moving on you.

I just noticed the manual is like 30mb, so I'll see if I can ZIP it down to a reasonable size... If not, I'll just break down and chop out all of the other languages like I did with the YZ250 manual I got. It's about time I got around to it.

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Sounds like you got a really good deal then! In that case, checking the clearance would be good, then in another 10 or so hours I would say just so you know when they start walking. I think I've heard a rule of thumb is after shimming them twice, it's time to get new ones because the hard coat on the titanium valve has worn off and they'll keep moving on you.

I just noticed the manual is like 30mb, so I'll see if I can ZIP it down to a reasonable size... If not, I'll just break down and chop out all of the other languages like I did with the YZ250 manual I got. It's about time I got around to it.

Just got it a couple of mintues ago, thanks!

Did I tell you what I paid for it? x)

..1300!

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No problem! With the small file size and lass pages I have it on my phone now for quick reference... I'm thinking a semi-ruggedized tablet is in order for the shop. I'll be able to pull up any manual I need and if I get a little oil or grease on it I can just wipe it off! Plus google, youtube, and thumpertalk for the stuff that isn't in the manual.

1300??? that's great for the condition it's in! You need to post up some pictures!

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This is just a quick one off of my phone. I have a 14.1in Laptop, I had a netbook but my hands are simply too big and the resolution on them is MUCH too low to comfortably navigate a PDF. An android tabelt would do great, seeing as it has quick touch to scroll features, and the "pinch" zoom.

vEhqk.jpg

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She looks familiar!

I'm thinking about picking up a Xoom tablet, I was doing some research last night and I think Panasonic is coming out with a new "Toughpad" that looks really nice, but it costs as much as that bike you just bought!

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Yea, I took a scotch brite pad and some wd 40 and wiped the surface rust right off, I'm thinking about fabricating some aluminum guards for it.

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