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chevy power

I have a few questions.

15 posts in this topic

Background: Bought an 03 wr450 for 1000$. I have about 450$ into it on top of that. It doesnt run very well right now. I replaced all o-rings, and diaphragms in the carb. Did the o-ring mod. Both dealers near me didnt have a 48 pilot so I went with a 45, and a 165 main. It had a 150 main, and a 50 pilot stock. I bought a works connection adjustable fuel needle. This thing is ready to ride besides it not running right.

Questions: I live in Ohio. I figure my elevation is around 1000ft here. The dealer should have a 48 pilot in on Friday. But I rode the bike up and down the street got it warmed up and started ripping on it. It will idle and die out I have played around with the fuel screw with no luck. Should I try to adjust the AP squirt? I have not touched it and wanted to leave it where I knew it would proably run. I have a quickshot on the way, got it on ebay for 35 shipped.

I can hear some valve noise at high RPM. I wanted to get it running and then do a valve adjustment, one less thing to have rule out. I am going to adjust them tonight after it cools down.

I need some help. I know that the carb is clean, and I have a feeling a valve adjustment will help but I feel like something else is up. Should I put the 50 pilot back in? Is there some other off the wall thing that would cause this? Gas is good, flushed the tank out 3 times, no sediment in the bowl of the carb.

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Besides the valves (if you can hear them, I can't imagine the bike running well at all...),

Check your float level.

Make sure that your carb slide isn't in backwards

check for air leaks.

Also, not all fuel needles are created equal. I had to use a GYTR needle on my WR250F because the other aftermarket brands have the wrong taper (the GYTR needle is much thinner and pointier at the tip).

If the bike won't idle on a 45 pilot, something else is wrong than the pilot size.

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I bought the stock needle, clip in the middle where it was on the old one. Float height could be an issue, I never messed with it but I know when Im kicking the hell out the bike some times a few drips will come out of the overflow, so I will check that.

And can someone describe the carb slide, I searched and didnt find out too much good info on how it is supposed to be in there.

And air leaks, Ive always heard to use solvent and spray around the carb boot and any where else where it could suck air.

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I am going to check my woodruf key, the starter has not been fixed yet. Still has the 03 parts and it doesnt work. I dont have the 200$ to fix it right now and would like to make it safe to ride, I think my key might be messed up causing my timing to be off. I cant really say until I get a chance to look.

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I'd be surprised if woodruff key is aproblem unless the bolt in the crank is loose.

If the slide in the carb is in backwards, the bike can be hard to start and won't idle worth a crap. The carb slide goes in so the hole in the vacuum plate on the slide is towards the intake boot.

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Hole is towards the intake boot. I pulled the gas tank and seat and drained the water I had in the system instead of coolant to flush it out and check for any leaks. Took the left side cover off, flywheel was tight, the starter works, all the gears except the one behind the flywheel were good. The gear behind could spin freely but got hung up in a few spots. Is this the idler gear that is the main culprit on the 03? (just trying to understand exactly what part fails).

I took the spark plug out while going about adjusting the valves and timing. It was wet and it wasnt gas. It was water, decided after measuring valve clearance. That I would pull the head, discovered water on the piston. I hope for some strange reason the head gasket blew. Oil was dirty after riding for a little while, but it wasnt abnormally milky or watered down. I figure this was just leaking coolant into the cylinder and not the case.

I think the water wasnt residual, it was raining all day but that much water over 4hrs doesnt seem plausible. The valves werent terribly out of spec, a few .1 of a millimeter at max. I will order some shims and a head gasket and cross my fingers the head gasket was causing me all of this grief.

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Looking forward to hear how that goes. :p

Dunno about the idler. I'd probably ask a real mechanic about it unless there were obvious burrs I could see. That would be telling.

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Background: Bought an 03 wr450 for 1000$. I have about 450$ into it on top of that. It doesnt run very well right now. I replaced all o-rings, and diaphragms in the carb. Did the o-ring mod. Both dealers near me didnt have a 48 pilot so I went with a 45, and a 165 main. It had a 150 main, and a 50 pilot stock. I bought a works connection adjustable fuel needle. This thing is ready to ride besides it not running right.

Questions: I live in Ohio. I figure my elevation is around 1000ft here. The dealer should have a 48 pilot in on Friday. But I rode the bike up and down the street got it warmed up and started ripping on it. It will idle and die out I have played around with the fuel screw with no luck. Should I try to adjust the AP squirt? I have not touched it and wanted to leave it where I knew it would proably run. I have a quickshot on the way, got it on ebay for 35 shipped.

I can hear some valve noise at high RPM. I wanted to get it running and then do a valve adjustment, one less thing to have rule out. I am going to adjust them tonight after it cools down.

I need some help. I know that the carb is clean, and I have a feeling a valve adjustment will help but I feel like something else is up. Should I put the 50 pilot back in? Is there some other off the wall thing that would cause this? Gas is good, flushed the tank out 3 times, no sediment in the bowl of the carb.

I live in Winnipeg Manitoba 780ft above sea level.

i used a 168 main jet and the RED needle from JD jetting kit.

my bike runs like a top... perfect. 08 WR450F

in the JD jetting instructions they say to use a 165 for 3000-6000ft

so sounds like you are still lean my friend :p by no means am i an expert!

good luck

cheers

Warts

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My friend actually had is YFZ re jetted, and I decided to run a 165 because it was free, his bike had a 42 pilot so I had to buy it but I am. I plan on getting the right things but I didnt have to go out of my way or pay 5$ for one. I found a head gasket in stock at a Yamaha dealer. Its 45mins away but hopefully I can get it together and ride this weekend. I will keep you all informed and Thanks for all the help.

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I started the bike after putting the head gasket and did the valve adjustment. It seemed to run good, it was 10 and I had rumors that my neighbors were irritated from my 10:45 start a few weeks ago (the 12 year old neighbor kid who thinks he is a bad ass said he heard from the kids parents were going to call the cops again if they heard anything) I started it up at 10ish, ran it around the yard a second seemed much better it idled fine shut it off and put all the plastics on. I will check for leaks, open it up and hopefully in the morning head for my usual place to rid.e

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Had a few issues, I flipped the ACV diaphram and it runs much better. I also am going to get the 48 pilot. I had a minor oil leak from a faulty o-ring, and found out that I should have replaced the water pump shaft. Heading to wayne national this weekend on it. I expect to have a great time. I will be riding with much more experienced riders which should be fun.

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Good call on flipping the ACV diaphragm. That bugger makes it hard as hell to adjust the mixture. But that brings up a point: Have you done all the "free mods" to your WR yet? They really wake up the bike.

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Did the o-ring mod for the AP pump, exhaust baffle is out, TPS is unplugged and gray wire is next to come unplugged, and putting some silicone under the chain slide on the swing arm. Carb also has a quickshot. Im finally getting the point where I think I can trust that I know all of the stuff I could check, I did, If another problem arrives I have this site and the repair manual to help me fix it.

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I'd put the TPS back unless you're having issues with it - well, that's my personal take on it. You'll like the gray wire mod! There's a skyblue wire mod too - (neutral switch). The skyblue mod helps with tuning the bike idle without having to hold the clutch in to get max spark in neutral.

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