MikeT

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Jan 17, 2001
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Dave, if after doing all those downhills with the throttle barely open had the plug looking good that would be different, but man, the thig was soaked! I already have a 50 in there and don't think a 45 will be that far off where it probably needs to be. I hope to get this all sorted out before the 4th.
 

MikeT

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Jan 17, 2001
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I put the needle on order and a local Honda Suzuki Dealer has the main and pilot jet in stock. Those will be factory parts and not aftermarket stuff. The 340 main along with the 45 pilot and the 70 needle and some air screw tweaking should be a good starting point. I'll keep you guys up to date on the progress.
 

skhasky

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Apr 8, 2002
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Good luck dude! I agree... 50 to 45 may not be enough, however.... Our bikes do like about 2 to 2 1/4 turns - never less than 1 1/2 - something about the THX carb... Keep me posted!

96Whyzee125... Needle Taper amd clip position. The taper tends to affect more at at low rpm when whacking open to full. The clip has more of an effect at higher RPM when whacking it open. The needle diameter effects the whole range, while the position sets the point of origin. Let me know what your problem is and I will see if I can help.
 

whyzee

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Skip, thanks for the clarification...Not sure I have a jetting problem as throttle response is excellent, and very crisp. Occasionally I get a little damp on the plug but color is perfect. If anything, I'm maybe a little rich at about 1/4 to 1/2 position.
 

MikeT

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Jan 17, 2001
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Originally posted by skhasky
MikeT - just to clarify - - I still hold by that 45 pilot, as the rest of the jetting will lean things out down there too.
OK, I'll be picking up the pilot and main on Saturday, and the needle should be in on Tuesday.
 

MikeT

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Jan 17, 2001
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Main jet question

OK, heres a inexperienced question. I just took out my 350 main jet and installed a 340 main jet. I looked at them and they both look the same. Is the difference in a 340 and a 350 measured in thousanths of an inch or something? I couldn't see any difference at all. I guess the difference is so small you won't be able to see it right?? :think:
 

skhasky

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Hey Dude! How's the 'project' going?
The difference between jets is measured in hundredths of a millimeter. We're talking about the hole in the middle. 340 - 350, you can't really see the difference with the naked eye. 300 to 350 - you definitely see the difference!
 

MikeT

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Jan 17, 2001
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OK, so by changing from a 350 to a 340 I wouldn't be able to see it anyway. That's good because I thought you could see the difference. Well, I'll have to also put the pilot on order because the one pilot the dealrship had was the wrong one. I am hoping to put that on order and hopefully recieve it by next weekend, I hope. The needle should be here on Tuesday. You think I should start out with the clip in the 3rd position??
 

MikeT

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Jan 17, 2001
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Zero. The jets STILL arent here and it looks like I won't be riding this weekend. Sort of a trade off. I give up this weekend and then ride the next two in a row. The Yamaha shop still has them on order and of course they "don't know" when they will be in...... So I sit and wait :(
 

MikeT

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Jan 17, 2001
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Skip, I am currently waiting on Yamaha to get the Pilot jet... They should have it today I hope.

I can't respond to you because you need to clean out your PM SENT box and your IN box. I sent you an email.
 

MikeT

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Jan 17, 2001
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Make sure you empty the "sent" folder.
 

MikeT

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Jan 17, 2001
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I just called the Yamaha shop and my jets are in!!! I'm going to pick them up tomorrow.
 

skhasky

Member
Apr 8, 2002
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The pilot is easy - once tha carb is off, it just unscrews from the bottom. The main and nozzle unscrew from the bottom as one and are easy to separate. The needle... what a pain! Once you get the slide out, leave the throttle cable attached. Grasp the spring and compress it with one hand (including the white plastic shim) and use the uther hand to hold the slide and work the cable around. It will pup loose. Once done, use the same sized socket you used on the main to remove the retainer in the slide. From there, the needle just pops out. When re-assembling hte needle, make sure the clip spins in the groove. You don't want it binding too much. Also, when you screw the retainer over the needle and hook up the cable to it, make sure to align the notch on the white plastic spacer with the notch on the retaining nut holding the needle in. If you don't you will hear clicking and feel binding when the throttle is operated. Look at the parts and you will see exactly what I mean. Good Luck!
 

MikeT

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Jan 17, 2001
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Skip, I've got the jets. What plug heat range do you think I should start with?? Put a 9 in there and then maybe give an 8 a go later in the day? Or should I just start out with the 8?
 

whyzee

Never enough time !
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Originally posted by skhasky
Once done, use the same sized socket you used on the main to remove the retainer in the slide. From there, the needle just pops out. When re-assembling hte needle, make sure the clip spins in the groove. You don't want it binding too much. Also, when you screw the retainer over the needle and hook up the cable to it, make sure to align the notch on the white plastic spacer with the notch on the retaining nut holding the needle in. If you don't you will hear clicking and feel binding when the throttle is operated. Look at the parts and you will see exactly what I mean. Good Luck!
Don't overtighten the retaining nut into the slide, FYI it's a 6mm, it will stress the nut and you won't be able to get your cable back into the slot.. :silly: ..yea first hand...good luck, see ya next weekend! :confused:
just ordered a 68 and a 70 needle.
 

MikeT

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Jan 17, 2001
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OK, I got the jets, changed the main to a 340, changed the pilot to a 45, turned the air screw 2 turns out, changed the needle to a 70 with the clip in the middle, sprayed all the holes clean in the carb, cleaned/oiled the air filter, new spark plug, repacked the silencer, lubed the swingarm (every piviot point), revalved suspension, new springs, lubed the chain. I am ready to ride!!

I think I might have to take the carb back off because I just caught the line you (Skip) wrote about the plastic spacer alignment. I didn't check that :silly: Probably better safe than sorry. I'll pull it just to be sure.
 
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MikeT

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Jan 17, 2001
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UPDATE !

Here is the jetting update. I went out to the track with a 340M/70-3/45P@2.0 turns/S-9/5.0. While riding I noticed the bike burbling at about ½ throttle. Wanting to be on the safe side I guessed that it was lean, so I took the carb apart and lowered the clip one to the fourth position from the top. Took the bike back out and that made it noticeably worse, so I came right back in. I took it apart again and raised the clip to the second position from the top and that made it MUCH better. The bike ran perfect, this all with a BR9 spark plug. The bike ran perfect, I think, but the plug was a little wet on the outside when I came in. That might be because I didn’t to a full throttle for 30 seconds then shut down. The bike “feels” fine but I wonder, if I should just change the plug to a BR8 or go leaner on the pilot or just leave it alone because it is running well. Oh, ya, no spooge and starts easily.
 

Rich Rohrich

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There are very few riders who can keep a bike running hard enough to warrant a 9 series NGK on a standard 125. Run the 8 until you get the jetting sorted then you can evaluate the plug temp. It's nearly impossible to get a good plug reading if the plug temp is too low.
Chances are good you'll never need the 9.

I ran my 01 CR125 very sharp (i.e. lean) with insanely high compression and fairly squirelly fuel and it didn't overheat a BR8EVX even at Casey with Jeremy Wilkey riding it for about 30-40 laps. Jeremy is an outstanding 125 rider, so he pushed it well beyond the point I was able to.
 

MikeT

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Jan 17, 2001
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Thanks Rich, That's what I needed to hear. I feel I'm getting close on the jetting but I just wasn't sure how much hotter the BR8 is. From what you wrote, it sounds like the last piece will be the plug. I never get spooge and the thing is running well, but I just don't seem to be getting that brown color out of the plug. I'll give that a go and see how it turns out this weekend. Thanks!
 
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