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What I'd Like to know: What exactly do I have to get checked on my 04' CRF250R? What are some things I can do on my own.

Info on bike: Let me tell you the story, I bought a 2004 CRF250R from a guy for 3500 and he told me he was selling it because he wanted an X not an R. I believed his sad sob story and bought the bike after basic inspection. He said he hadn't changed anything in the engine (piston/shims/valves/camshaft) and that everything was stock on the bike. My bike has always been a little rough to start, like 4-5 hefty kicks but you always knew there was the compression and it would run like a 250 should run. It never felt like it had much high rpm power but I thought that might have been the bike. Just this last week I had had my mechanic put in a new piston, (I put in all new gaskets all the way to where I ripped it down to) and also put in new valves. He said its never been reshimmed... but I think otherwise. I put about 20 hours on the bike with normal routine maintenence and have raced it 3 times decently hard up at the track but not wide open the whole time. (I had him put in OEM valves for now)

The Questions:

1) Do the torque settings really matter inside the engine or can you just do the feel approach? (I'v snapped 4 bolts because my torque wrench didn't read the torque right)

2) It overheats a lot and I have almost full radiator fluid after every ride (no leaks). But yet it still overheats.. does this mean I need to get something else checked?

3) It backfires every now and then when I try to kick it. Is that a sign of anything bad?

4) It doesn't bog at all, but could I still get more performance if I rejetted it? I have stock 158 main jet in I beleive.

5) What are the things that really make a bike handle well? ( My buddy has a 2stroke 125 and its beautiful. I don't know what makes it feel so good when your on it)

6) And what are the cheapest mods I can do to my bike that will give me the highest performance gain? (Do those powernow valve's work?)

Thanks to anyone who can help me and I know i'm asking a lot but I'm a little confused and in need of help on what I need to look at on my four stroke and what I can customize to make it the best of the best.

Ryan

#08

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What I'd Like to know: What exactly do I have to get checked on my 04' CRF250R? What are some things I can do on my own.

Info on bike: Let me tell you the story, I bought a 2004 CRF250R from a guy for 3500 and he told me he was selling it because he wanted an X not an R. I believed his sad sob story and bought the bike after basic inspection. He said he hadn't changed anything in the engine (piston/shims/valves/camshaft) and that everything was stock on the bike. My bike has always been a little rough to start, like 4-5 hefty kicks but you always knew there was the compression and it would run like a 250 should run. It never felt like it had much high rpm power but I thought that might have been the bike. Just this last week I had had my mechanic put in a new piston, (I put in all new gaskets all the way to where I ripped it down to) and also put in new valves. He said its never been reshimmed... but I think otherwise. I put about 20 hours on the bike with normal routine maintenence and have raced it 3 times decently hard up at the track but not wide open the whole time. (I had him put in OEM valves for now)

The Questions:

1) Do the torque settings really matter inside the engine or can you just do the feel approach? (I'v snapped 4 bolts because my torque wrench didn't read the torque right)

2) It overheats a lot and I have almost full radiator fluid after every ride (no leaks). But yet it still overheats.. does this mean I need to get something else checked?

3) It backfires every now and then when I try to kick it. Is that a sign of anything bad?

4) It doesn't bog at all, but could I still get more performance if I rejetted it? I have stock 158 main jet in I beleive.

5) What are the things that really make a bike handle well? ( My buddy has a 2stroke 125 and its beautiful. I don't know what makes it feel so good when your on it)

6) And what are the cheapest mods I can do to my bike that will give me the highest performance gain? (Do those powernow valve's work?)

Thanks to anyone who can help me and I know i'm asking a lot but I'm a little confused and in need of help on what I need to look at on my four stroke and what I can customize to make it the best of the best.

Ryan

#08

sounds like some average rider that did not maintain the bike, and wanted to sell it because he wanted to throw the crap on someone else. i was in the same boat as you. barely any mainteniace. had to do new top end, was bad oil inside and HORRIABLE air filter :ride::applause:

i bought a craftsmen for like 80 bucks that works good i would recemend getting one because for some reason i always want to tighten a bolt more... :thumbsup:

check that hole at the bottom of the water pump for leaking , im not sure about it but it could be a bad water pump, needs rebuilding or even and plug up? i would also recemend engine ice. worked way better then the honda stuff.

also does it over heat when your riding or just idleing?

first thing i think of with the backfire is jetting. also ansewering the other question getting the JD jetting kit works GREAT for the 04's for performance. and its good pricing

i would rejet it with JD kit. 04 jetting isnt that good*from what i hear*. i got it and it makes my bike run noticably better

as far as handling not sure. im still learning the ins and outs to the bike myself. the service manual does wonders. im going to start learning about suspension next.

not sure on cheap mods im sure someone with more knowledge can help ya out. its all expensive to me. upgraded cam? JE or JD piston? stainless steel valves. d.i.d. chain? i got a ironman sprocket i heard they are good ima put that baby on tomorrow,.....nothing else i can think of off top of my head.

overall i would get that jetting done first.

definitly buy tools to do the reshimming and jetting done yourself.

good luck

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Thanks so much donny, I need a good torque wrench, I spent like 50 for an ace one and it kills my bolts. I'm sure that Im using it right too because i even read the instructions after being unsure. (snapping 2-3 bolts) I'm pretty sure he knew the bike was a timebomb about ready to blow because his original price was 3,800 firm but somehow he haggled down.

JD Jetting kit - I'v heard that it does wonders for 250F's. Definately will look into.

Backfires - I'll look into changing the jetting then, too lean or too rich or could it be either??

Overheats - The bike overheats when riding, never when idling, but my friends 250F that races never gets as hot as mine and he's an intermediate rider who rides it pretty hard. You'd imagine my riding (beginner class) wouldn't be anything abusive compared to his. He's got an 05' if that makes a difference. I'll look into the waterpump.

Thanks again, I love thumpertalk now. First time I ever posted something and it was replied to ASAP.

*EDIT* - Also, is the FMF better or worse than the JD. Definately not looking to put FMF exhaust on my bike. I'm saving for a Carbon pro series 2 Ti by WB.

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i believe backfiring is to lean. like if you turn off the fuel and run the bike dry in the carb you will notice backfiring.

as far as 1st hand experience in camparing the fmf and JD jetting, im not sure. i posted i was getting the fmf and someone recemended me getting the JD instead. i love it. james dean also posts here on TT you can ask him a question yourself if you have any problems jetting with his kit.

thats definitly not good with your overheating while running. hopefully someone with alot more knowledge might have something else on that as im not elite yet with bike repairing.

also just a thought your carb could be dirty/clogged somewhere inside if it is jetted properly. if you get the service manual that thing does wonders*if you want to do the work yourself*. i cant remember if i stated that in last reply :ride:

yea im fairly new to TT also. i've learned so much from everyone here.

goodluck!:thumbsup:

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if your scrounging for money, go to the local shop with your main jet, and tell them you want the next size bigger (in your case i think its a 164)

also the radiator problem, drain out all of your collent threw the little plug on the bottom right of your water pump, and then take yout pump cover off, inspect to make sure there isnt any of that radiator sealent (it should be brown, or have little brown what looks like pieces of dirt), if that is in there your going to have to flush out your system.

powernow and power plus doesnt work, dont waist your time, invest into a good twin air air filter and you will be all set

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I need to get a copy of the service manual - thanks donny.

and i'll just get the JD kit over the next size jet up. I have the money for it so might as well do it before I run out again. When you are too lean you go up in jets? How do you know when its just perfect? Is it a feel how the bike runs?

I took the whole carb apart and cleaned it because it was all dirty which was really not a good sign so I sent it to the shop to have them flush it and clean everything in the bike so that it was like a new bike, but dirt keeps getting in (I clean my air filter after every ride or sometimes I didn't ride that long and its not dirty so i'll leave it until the next ride).

What should I have inspected that might be letting dirt in the carb?

I'm all for saving money and doing the work myself, am I just looking up a Honda 2004 CRF250R Service Manual?

And should I just buy the JD jetting kit off TT? I noticed its decently priced, does that contribute to keeping the forums alive and all? If so I wouldn't mind spending a little extra.

As for the twin air filter, is it just the Dual stage air filter or is it some kinda kit that I need to look for? I also saw the : PowerFlow Kit...

http://shop.twinairusa.com/catalog/default.php?cPath=2_9

Is that the thing? Will it give me more performance?

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08- I cut out the backfire screen almost immediately. No problems. Make sure you get a Pro Seal as soon as you can for your airbox.

I have craftsman torque wrenches also and they are good.

Get that service manual as soon as you can. You will have it jetted in no time with the jd but just make sure you run some searches on TT and learn how to route the tubing better and get everything adjusted properly.

There are lot's of little things to check from the screw on your gas tank to the spokes and sag. Good luck man! :thumbsup:

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Can I just cut out the backfire screen on my old stock air filter instead of buying the new powerflow kit?

yeah just do that the powerflow isnt all that exciting.. its just bling :thumbsup:

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I need to get a copy of the service manual - thanks donny.

GO to eBay and find one from CycleManuals. I got one for my 2005 CRF250r for $25 with shipping. Saved me a ton of money already and I have soooo much more to learn.

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I took the whole carb apart and cleaned it because it was all dirty which was really not a good sign so I sent it to the shop to have them flush it and clean everything in the bike so that it was like a new bike, but dirt keeps getting in (I clean my air filter after every ride or sometimes I didn't ride that long and its not dirty so i'll leave it until the next ride).

What should I have inspected that might be letting dirt in the carb?

Check your gas tank. drain the gas, take the tank off the bike and clean it. even though you might think you keep dirt from getting in there you may be suprised. also check any fuel filter you have to see if it is broken and letting dirt in.

if you dont have a fuel filter, you might want to get one.

also some people grease the mating surface where the air filter meets the airbox, this catches dirt that tries to leak through if you dont get it fully sealed.

as far as backfiring when starting it, it really depends. i think generally a backfire is when unburned gas gets into the exhaust system then ignites, meaning a rich condition. the reason i say it really depends is that it could be any number of things. you could have grabbed the throttle a little bit while moving the bike, letting gas into the engine when it shouldnt be. your pilot screw could be slightly out of adjustment. if you have kicked it a few times and then it backfires you probably pumped some gas in there and it just finally burned. if it isnt constant i dont think it is anything to worry about.

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