KX Riders
Maintenance & Technical => KX500 Original => Topic started by: dmg on February 01, 2009, 11:27:50 AM
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I need some thoughts and suggestions.
The past two weeks I tore the bike apart, cleaning and fixing small things. KX500 is all stock except for a FMF Gnarly pipe.
1) I took the carb off, and cleaned it well.
2) I replaced the stock reed(broken) with a Boyseen Dual Stage reed(four flaps instead of two)
3) Replaced spark plug from a B8ES to a B8EG
4) Cleaned and oiled the air filter.
5) Fuel is the same as I ran before this work.
Before all this work, the bike ran good at the bottom and mid, but had no power at the top end. Went out yesteday for the first time since the new parts and clean. Now, the bike runs loaded all the way up to the very top of the rpm range. It barely cleans out right at the top, and it pulls GOOD at the top. Much better than before.
I attributed the poor top end performance to the broken reed.
What could be causing the loaded running performance. Could it be the different plug? The new reeds? Over oiled filter? I didn't adjust anything in the carb when I had it apart for cleaning. My dad oiled the filter, so this is the first thing I will check. I will just clean it out, and run it dry down the street to check.
Any suggestions or thoughts?
Darin
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I need some thoughts and suggestions.
The past two weeks I tore the bike apart, cleaning and fixing small things. KX500 is all stock except for a FMF Gnarly pipe.
1) I took the carb off, and cleaned it well.
2) I replaced the stock reed(broken) with a Boyseen Dual Stage reed(four flaps instead of two)
3) Replaced spark plug from a B8ES to a B8EG
4) Cleaned and oiled the air filter.
5) Fuel is the same as I ran before this work.
Before all this work, the bike ran good at the bottom and mid, but had no power at the top end. Went out yesteday for the first time since the new parts and clean. Now, the bike runs loaded all the way up to the very top of the rpm range. It barely cleans out right at the top, and it pulls GOOD at the top. Much better than before.
I attributed the poor top end performance to the broken reed.
What could be causing the loaded running performance. Could it be the different plug? The new reeds? Over oiled filter? I didn't adjust anything in the carb when I had it apart for cleaning. My dad oiled the filter, so this is the first thing I will check. I will just clean it out, and run it dry down the street to check.
Any suggestions or thoughts?
Darin
http://www.kxriders.com/forums/index.php/topic,4816.0.html
This is the jetting chart I used and it worked out great!
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D,
The Do you know off hand what you have as far as jetting now?
This is off Boyeson: http://www.boyesen.com/cwo.php?id=14&id2=20&id3=&page_id=13
MODEL Main CLIP SLOW JET AIR SCREW
KX500 90-04 stock 168 3 58 1 1/2
Power Reeds (615) 162 3 58 1 1/2
PRO Series (PRO-45) 162 3 58 1 1/2
RAD Valve (RAD-13) 160 3 58 1 1/2
FMF http://www.fmfracing.com/techsupport/jettingcenter.aspx
FMF Gnarly '92 KX500
"Here is what we've come up for in our area and is a great starting point for you as well. There are way too many variables in jetting to give you a recommendation that works perfect. Use these specs for a reference to help aid you with your specific bike. We developed these specs with a 32:1 fuel to oil mixing ratio of a 50/50 mix of race fuel and super unleaded, 0 - 1500 ft altitude at 70 degrees outside temperature."
Jetting Information
Main Jet: 168
Pilot Jet: N/A
Needle: N82M
Needle Position: 3RD
Air Screw: 1.5
Tuck\o/
Darin Check this out : http://www.kxriders.com/forums/index.php/topic,5072.0.html
It would be cool if you guys could get together and compare notes.
Serafin and KXPegger are also in Vegas!
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DMG,
It sounds to me like the float needle may be leaking, possibly assembled wrong? As long as your jetting is about what the chart says that's one of the few thing that would cause a richness across the whole rpm range. I woud suggest checking it and verifying the float level is correct. There are also instances where the needle is not seated fully in slide. I have done both of these myself. Cam.