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Just_a_trail_rider

I screwed up my carb settings

13 posts in this topic

OK, I need a little advice.

Usually, I am more of a rider than a wrench. Because of time constraints, I usually put my bike in the shop whenever there is a problem.

however, I thought I would spend this weekend getting familiar with my wr450. It has run great for me, but I want to get familiar with it.

So, I practiced removing and replacing the front and rear tires and tubes (good practice). Then I changed the oil and filter (so many bolts!).

Lastly, I changed the plug. Didn't need it really, but its good to know how to do things things BEFORE I get stranded out in the middle of the desert.

Then I checked the jets on the carb. the guy I bought the bike from last year had already installed the JD jet kit and a zip ty (I think???) fuel screw. I verified that the the 170 main jet was installed and that the blue needle was in the 4th position. (So now I know what you guys are talking about). I am assuming that the stock pilot jet in installed (45?).

The bike started and I let it idle for about 15-20 minutes with no problems.

Then I started messing with the fuel screw. Now it won't start. What is a good starting poing for the fuel screw.

Should I screw it all the way in and then back it out 1 1/2 turns?

A little advice would be appreciated.

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Should I screw it all the way in and then back it out 1 1/2 turns?

Yep, good place to start.

Then look here HERE

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OK, I got it running again. I screwed it all the way in and went out about 2 turn. After a while, it fired up. I also had the idle set very, very low. It is behaving much more predictably now.

This is once cold blooded animal. Even with the e-start, it doesn't fire up as easily as the ttr125. Of course, this is an issue because my battery was really low and I tired myself out trying to kick start it.

Will a different pilot jet help? Or do I need to tweak the fuel screw some more.

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If jetted properly it should fire up very easy with the e-start.

Before my 06 was jetted better than stock it was vert cold blooded. Now, just pull the cold start knob on the carb. Give it one twist of the throttle (if cold). hit the button it starts right up. Regardless of temperature.

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What pilot jet are you running? Is it a 45 or a 48?

The bike runs great when I am riding it.

but starting it isn't as smooth as it should be. I mean... it starts, but my daughters CRF100 starts on the first kick. The WR450 needs a little effort, even with the e-start.

In an ideal world, I would want it to kick start cold as easy as my little honda.

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I currently running:

Main : 168

Pilot : 45

Starter : 65

Leak : 35

This weekend I going to try a #0 leak and move the pilot to 42 and then 48 to test the effects.

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What pilot jet are you running? Is it a 45 or a 48?..... but starting it isn't as smooth as it should be.
I run a 45 in the summer (90+, humid, sea level) and a 48 in cooler temps. If you're talking about cold starts with the choke, try a bigger starter jet. I use a #70 year round. :thumbsup: Hot starts, try adjusting the fuel screw and/or raising the idle. With my bike jetted right all I do is push the hot start and the e start (no throttle) and it fires right up.

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The bike started and I let it idle for about 15-20 minutes with no problems.

:thumbsup::thumbsup::bonk:

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:thumbsup::bonk::confused:

I agree. That is a long ass time to be sitting there idling without overheating. Did they start putting cooling fans on these bikes that I'm unaware of? :thumbsup:

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Maurice, I would reckon that if you run a 170 main jet (and it runs well with that) at sea level to 1000ft, you would need a 48 pilot jet. I ride from sea level to 3000ft, 5 degrees C to 35 degrees C and the bike starts straight away every time. I only ever need to adjust the fuel screw 1/4 to 1/2 a turn. I use a 170 MJ and 48 pilot, never touched the starter but maybe the Ausie bikes have a different size starter jet? If you have trouble starting cold, try the choke. If that doesn't make it better, try the hot start. NO THROTTLE AT ALL. They definitely don't like any throttle when starting. If you don't need the choke or if you need the hot start to start from cold it is too rich in the pilot. If you have the choke out and it doesn't start easily try opening the throttle 3 times quickly before hitting the button and see if that helps. If it does, you probably need a bigger pilot jet. When everything is right you should need the choke to start, then the hot start when it is warmed up. If its very cold, I may give the throttle 3 quick blips before starting it to squirt a bit of fuel down the carby. I never idle my bike for longer than 2 or 3 minutes.

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I ride at the same elevation as you but maybe a bit cooler temps. I found a 48 pilot much better than the 45 year round. It's also really important not to have the idle set too low. 1900 sounds pretty fast when it's sitting there idling but if you set it too low it gets hard to start. I can't believe your bike will idle for more than 10 minutes without overheating. Good to hear that your practicing doing your own maintenance and repairs, its part of being of a dirtbiker!

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OK, I definitely won't let it idle for long anymore. I had to keep it running while I was screwing around with the carb. It didn't overheat and do any damage that I know of. I got nervous after reading the posts and took it for a quick spin around the neighborhood to make sure.

BTW... riding around the block is not something I normally do.

Today I found that the guide holder for the airfilter is broken. So I cannot secure my air filter into place. According to Yamaha parts list, its only 10 bucks. But I definitely can't go riding untilI fix that.

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Maurice, I would reckon that if you run a 170 main jet (and it runs well with that) at sea level to 1000ft, you would need a 48 pilot jet. I ride from sea level to 3000ft, 5 degrees C to 35 degrees C and the bike starts straight away every time. I only ever need to adjust the fuel screw 1/4 to 1/2 a turn. I use a 170 MJ and 48 pilot, never touched the starter but maybe the Ausie bikes have a different size starter jet? If you have trouble starting cold, try the choke. If that doesn't make it better, try the hot start. NO THROTTLE AT ALL. They definitely don't like any throttle when starting. If you don't need the choke or if you need the hot start to start from cold it is too rich in the pilot. If you have the choke out and it doesn't start easily try opening the throttle 3 times quickly before hitting the button and see if that helps. If it does, you probably need a bigger pilot jet. When everything is right you should need the choke to start, then the hot start when it is warmed up. If its very cold, I may give the throttle 3 quick blips before starting it to squirt a bit of fuel down the carby. I never idle my bike for longer than 2 or 3 minutes.

This is good advice. I will try this approach. Thanks

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