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I'm at the top clip position on my needle... Now what?

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I'm at the top clip position of the EW needle on an '07 YZ250 (stock pipe and head). The bike runs OK, but it's only 50- 60 degrees here... I'd like to be able to jet leaner when the weather gets warmer, but what choices are out there for this? Different needle or slide?

 

Thanks!

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There are definitely leaner needles that will put you in a clip position that will still give you adjustment up or down. For example you could order the n3cw needle and It will be a half a clip position leaner in the same spot. So if you were in clip position 2 on you n3ew needle and you put the the n3cw needle in on 2nd position it would be the same as having your new needle in position 1.5

However I'm sure you'll want to be able to go leaner than a half a clip more than you are now so you should probably research for a considerably leaner needle or wait for someone wiser to chime in ....as the usual n3ej or n3ew needle give me enough adjustment at 1200ft. Although I'm also considering ordering the n3cw myself just to be able to tune as fine as a half a clip

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what's your riding style with that needle position. I run the blue JD needle at the leanest position on my overbore YZ260 engine.

 

I'm getting back into MX track days after about a 20 year break... ;)  Trying to go fairly quick without killing myself at this point, and still learning the bike. I seem to spend a good bit of time at part throttle, some full on.

 

 I'm running a 175 main and a 45 pilot right now. About 700 ft elevation.

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I believe the n3ej needle is a leaner taper (wider needle), so you could try that.  I don't think it's very common for people to max out their needle adjustment... Personally I found that the 45 pilot is a bit lean for me, so I'm gonna try out a 48 for a bit. 

 

Since enriching the pilot circuit will slightly enrich the whole range, it might be worth a try.

 

ETA: MI elevation is similar to your 700ft you listed.

Edited by JFielder23

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I believe the n3ej needle is a leaner taper (wider needle), so you could try that.  I don't think it's very common for people to max out their needle adjustment... Personally I found that the 45 pilot is a bit lean for me, so I'm gonna try out a 48 for a bit. 

 

Since enriching the pilot circuit will slightly enrich the whole range, it might be worth a try.

 

ETA: MI elevation is similar to your 700ft you listed.

 

OK, Thanks!

 

I'm starting to suspect a leaky crank seal. I changed my oil and carefully measured and recorded the amount I added. I'll rideit a few times, and then drain it and see where I'm at... 

 

Putting new reeds and needle (for the float) in it this weekend, so I'll see if that makes any difference, first, and go from there.

 

Thanks for the help guys...

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I'll throw out 1 other possible cause - the needle jet in the carb is worn; unfortunately, this is not a replaceable part on a Keihin. Sometimes you can actually see that the needle jet hole is oval when looking down thru the top of the carb after removing the slide (of course). Happened to me on my '03 YZ265WR with an unknown but huge number of hours. I could actually see the oval in the needle jet. I expected to see wear on the front side of the needle jet but the wear was actually on the sides. When you have chased a gazillion jetting combinations and nothing works you need to take a close look at the needle jet. I finally narrowed it down to the carb body by borrowing a carb off an identical bike - my bike ran great all day.

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OK, Thanks!

 

I'm starting to suspect a leaky crank seal. I changed my oil and carefully measured and recorded the amount I added. I'll rideit a few times, and then drain it and see where I'm at... 

 

Putting new reeds and needle (for the float) in it this weekend, so I'll see if that makes any difference, first, and go from there.

 

Thanks for the help guys...

I agree 100% with what he said. I would try a leaner pilot first off.

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I believe the n3ej needle is a leaner taper (wider needle), so you could try that. I don't think it's very common for people to max out their needle adjustment... Personally I found that the 45 pilot is a bit lean for me, so I'm gonna try out a 48 for a bit.

Since enriching the pilot circuit will slightly enrich the whole range, it might be worth a try.

ETA: MI elevation is similar to your 700ft you listed.

Hmmmm, well I have to run a 42 pilot....

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Just have to ask but what's the condition of your top-end? A worn top-end can greatly affect jetting....

 

Brand new OEM piston and rings. Less than two hours on it.

 

Power valves were cleaned. New muffler packing. Carb was cleaned. The only thing I didn't do was to replace the float needle and reeds. My reeds looked OK, couldn't see any daylight through them, but I picked up some new ones anyway as I have no idea as to when the prior owner replaced them last. Have a new float needle now as well.

 

My power valve vent hose is dripping black and brown goo, which is also leading me to believe I'm sucking up tranny oil (because of the brownish color)...

 

How difficult is a crank seal replacement on the right side? I had no problems doing a top end, but haven't done a seal replacement before... Anything else I should replace while I'm in there? Water pump seals?

Edited by Clip67

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Hmmmm, well I have to run a 42 pilot....

 

My air screw setting is constantly changing with the weather getting cooler. I seem to be running between 1.75 and 2.25 or so with the 45 pilot, so I didn't want to go leaner on the pilot for now.  When I made the change in the needle clip to the highest position, I saw a big improvement.

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Brand new OEM piston and rings. Less than two hours on it.

 

Power valves were cleaned. New muffler packing. Carb was cleaned. The only thing I didn't do was to replace the float needle and reeds. My reeds looked OK, couldn't see any daylight through them, but I picked up some new ones anyway as I have no idea as to when the prior owner replaced them last. Have a new float needle now as well.

 

My power valve vent hose is dripping black and brown goo, which is also leading me to believe I'm sucking up tranny oil (because of the brownish color)...

 

How difficult is a crank seal replacement on the right side? I had no problems doing a top end, but haven't done a seal replacement before... Anything else I should replace while I'm in there? Water pump seals?

 

Right side crank seal isn't too hard.  I did both sides on mine in about an hour or so.  Check out the Rocky Mountain MC bottom end videos for reference (they are at the bottom of the home page there, it's under "intructional videos" then in the "how to split the cases and replace crank bearings" video.  Don't worry, you don't need to split the cases OR remove the engine from the bike to do this).  A lot of guys replace the water pump seals while they're in there.  I didn't, but I probably should have. If you do the dry side seal, make sure you check out the timing thread in the Faq's thread at the top, because resetting the timing is probably the trickiest part.  (you can make your own timing tool with a cheap harbor freight dial indicator and an old spark plug and some sticky tac :thumbsup:  cheap and it works).

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Right side crank seal isn't too hard.  I did both sides on mine in about an hour or so.  Check out the Rocky Mountain MC bottom end videos for reference (they are at the bottom of the home page there, it's under "intructional videos" then in the "how to split the cases and replace crank bearings" video.  Don't worry, you don't need to split the cases OR remove the engine from the bike to do this).  A lot of guys replace the water pump seals while they're in there.  I didn't, but I probably should have. If you do the dry side seal, make sure you check out the timing thread in the Faq's thread at the top, because resetting the timing is probably the trickiest part.  (you can make your own timing tool with a cheap harbor freight dial indicator and an old spark plug and some sticky tac :thumbsup:  cheap and it works).

Thanks, I'll check that out.

 

I replaced the reeds with Boyesen Power Reeds, and put in a new needle valve under the float. Checked the floats while I was at it and they are in spec. I did discover that one of the carb vent hoses (the one right beside the choke) was not attached and just hanging freely. I don't know if this had much impact or not on the jetting issue and have no idea how long it has been like this - I don't know how I missed it!!

 

First ride on the bike after these changes and I immediately saw less smoke and very little spooge at the pipe and also very little at the PV breather hose.  The bike ran really well after I set the air screw. I have not done any other jetting changes for now as it seems to run well where it is.  I looked at the plug after some wide open second and third gear runs and a power chop... Nice and tan now!

 

I'm still going to measure the oil level after a few more rides to make sure I'm not sucking oil, but it is running much better than it was.

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My 2007s, I've had three of them now. All liked #9 slides. A lot of guys here like #8 slides. Almost everyone who has tried a leaner slide, loved it immediately. That blubber that you are trying to eliminate with your needle is caused by the #7 slide that is in the bike. 

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My 2007s, I've had three of them now. All liked #9 slides. A lot of guys here like #8 slides. Almost everyone who has tried a leaner slide, loved it immediately. That blubber that you are trying to eliminate with your needle is caused by the #7 slide that is in the bike. 

 

Great - thanks!

 

I did some searching and reading on the #8 slides, and think I'll be getting one from JD Jetting. Sounds like it would help a lot... I'll see how the #8 goes - if I need to go further then I'll pick up the #9. Are there still issues with the cable holder? 

Edited by Clip67

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Great - thanks!

 

I did some searching and reading on the #8 slides, and think I'll be getting one from JD Jetting. Sounds like it would help a lot... I'll see how the #8 goes - if I need to go further then I'll pick up the #9. Are there still issues with the cable holder? 

Yup. JD sells the cable holder. Don't ask me how I know that you'll break your needle off if you don't buy the cable holder. I still carry a needle in my butt bag. :) RB Designs will cut your stock slide if you decide that you'll never need it again.

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