KLX 250 ( 300 ) camshaft mod by Marcelino

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  #131  
Old 06-25-2011 | 11:24 PM
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don't you need to do both cams to get the results?
 
  #132  
Old 06-26-2011 | 12:05 AM
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I was thinking the same thing GaryC.
I would really like to see some dyno results of before and after.
 
  #133  
Old 06-26-2011 | 12:08 AM
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If I pull my valve cover off and take a picture of my cams, will you be able to tell if I did the mod correctly? Just want to make sure I didn't retard it because I sort of have that muddy intake noise when I am mid range through the gears. I'll make sure it's aligned on the T too.
 
  #134  
Old 06-26-2011 | 01:25 AM
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Default Intake Side Modded OK

It wasn't too bad of a mod session. Took 2.5 to 3 hours to complete and I felt in control and comfortable with things throughout. Just make sure you thoroughly read Marcelino's post until you understand it. Run results seemed OK but with some confounding conditions thrown in.

My intake cam was set up to look the same as Marcelino's by resetting the sprocket bolts' position to advance by 2.5 teeth and then retarding with the chain by 2 teeth. Looks like David R's is set the same. I think it's OK.

Wanted to go get some bar stock later on to be able the press the ACR out of the exhaust cam shaft to do that part later on but forgot to take a measurment of the ID of the shaft and depth that the ACR is pressed in. I could kick myself for forgetting. If anyone else is going to be under the valve cover could they please take these measurements? Or else let me know what they used for pressing the ACR out/in? I really would like to do the exhaust side, too.

Everything reassembled OK by the book for torques, etc. The most difficult part was keeping up with that friggin valve cover gasket with all its curves and grooves. Got the cover on and started tightening bolts then saw a little loop of the gasket sticking out in the spark plug well area. Fixed that and finished reassembly.(Made me think a bit of jhoffy22's oil problem but I think he's got that fixed, now)

Bike started right up with no fuss or leaks. Test ride #1 was just in the local town area to make sure that I didn't make any mistakes that would have catastrophic results and have me walking the bike back home from many miles away. It passed that test so on to #2.

Test ride #2 was out on some county pavement. Going out I was pushing a 15+ mph headwind at between 55-60 mph speed. Throttle was around 1/2 throughout against the wind. Not bad at all. The mod seems to have woke up the bike a little in the mid range like Marcelino said it would. Coming back with tail wind at the same speed, used only 1/4 throttle for the most part. Maybe with no wind the throttle would be 3/8? Just speculation.

The confounding conditions mentioned above were that for this ride, it was windy with 101 degrees temperature. Not really ideal conditions to test in but you have to take what you get.

One thing that really sent a cold chill down my spine on a hot summer day was when I got to my turnaround point about 9 miles away in the middle of nowhere and put the bike into first it died. Here I am where it's hot enough to fry an egg on the road and doing a test ride for some pretty heavy duty engine maintenance and my bike isn't running anymore. OMG. Then I noticed that my clutch lever felt kind of mooshy. Turns out that the clutch lever adjusting lock nut had chosen this very ride to loosen up. Just a reminder from the maintenance gods to not get cocky. Whew! Fixed that and came on home.

For jetting, this time of year could be a challenge since it's nice and cool most mornings but very hot later in the day. My jetting is presently set up with the hotter part of the day in mind.

Will try to test again tomorrow morning when it should be a little cooler and calmer outside (I hope). Looks like I'll be a guinea pig for a while with this mod.
 
  #135  
Old 06-26-2011 | 01:38 AM
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Hi all,
I'm a new owner of a 2009 klx and was sent to see this thread from ADVRIDER.
This mod is just what I've been looking for.
It should help the bike pull at highway speeds.

One question.
Is there mention of changing the spark timing at all?
 
  #136  
Old 06-26-2011 | 01:45 AM
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Originally Posted by bumblebee
Is there mention of changing the spark timing at all?
It's been discussed at length somewhere inside this (Marcelino's) thread.

Doesn't seem to be much you can do about it. The ones for OZ have more advance but they would co$t you.
 
  #137  
Old 06-26-2011 | 01:47 AM
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Originally Posted by kansas-klx
It's been discussed at length somewhere inside this (Marcelino's) thread.

Doesn't seem to be much you can do about it. The ones for OZ have more advance but they would co$t you.
So what's the verdict on it?
Do we just ignore it and go ahead with the cam changes?
 
  #138  
Old 06-26-2011 | 01:57 AM
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Originally Posted by kansas-klx
It wasn't too bad of a mod session. Took 2.5 to 3 hours to complete and I felt in control and comfortable with things throughout. Just make sure you thoroughly read Marcelino's post until you understand it. Run results seemed OK but with some confounding conditions thrown in.

My intake cam was set up to look the same as Marcelino's by resetting the sprocket bolts' position to advance by 2.5 teeth and then retarding with the chain by 2 teeth. Looks like David R's is set the same. I think it's OK.

Wanted to go get some bar stock later on to be able the press the ACR out of the exhaust cam shaft to do that part later on but forgot to take a measurment of the ID of the shaft and depth that the ACR is pressed in. I could kick myself for forgetting. If anyone else is going to be under the valve cover could they please take these measurements? Or else let me know what they used for pressing the ACR out/in? I really would like to do the exhaust side, too.

Everything reassembled OK by the book for torques, etc. The most difficult part was keeping up with that friggin valve cover gasket with all its curves and grooves. Got the cover on and started tightening bolts then saw a little loop of the gasket sticking out in the spark plug well area. Fixed that and finished reassembly.(Made me think a bit of jhoffy22's oil problem but I think he's got that fixed, now)

Bike started right up with no fuss or leaks. Test ride #1 was just in the local town area to make sure that I didn't make any mistakes that would have catastrophic results and have me walking the bike back home from many miles away. It passed that test so on to #2.

Test ride #2 was out on some county pavement. Going out I was pushing a 15+ mph headwind at between 55-60 mph speed. Throttle was around 1/2 throughout against the wind. Not bad at all. The mod seems to have woke up the bike a little in the mid range like Marcelino said it would. Coming back with tail wind at the same speed, used only 1/4 throttle for the most part. Maybe with no wind the throttle would be 3/8? Just speculation.

The confounding conditions mentioned above were that for this ride, it was windy with 101 degrees temperature. Not really ideal conditions to test in but you have to take what you get.

One thing that really sent a cold chill down my spine on a hot summer day was when I got to my turnaround point about 9 miles away in the middle of nowhere and put the bike into first it died. Here I am where it's hot enough to fry an egg on the road and doing a test ride for some pretty heavy duty engine maintenance and my bike isn't running anymore. OMG. Then I noticed that my clutch lever felt kind of mooshy. Turns out that the clutch lever adjusting lock nut had chosen this very ride to loosen up. Just a reminder from the maintenance gods to not get cocky. Whew! Fixed that and came on home.

For jetting, this time of year could be a challenge since it's nice and cool most mornings but very hot later in the day. My jetting is presently set up with the hotter part of the day in mind.

Will try to test again tomorrow morning when it should be a little cooler and calmer outside (I hope). Looks like I'll be a guinea pig for a while with this mod.
Can you please elaborate on what you meant by punching the ACR out? When I did the mod I never punched anything out. I just moved the cam sprockets.

EDIT: Just re read the original post. I didn't do anything with the ACR. This explains why I have muddy middle range. I am not getting good compression and still have the intake grawl and not enough exhaust. I actually think it got quieter when I just rotated the cam sprocket bolts and did nothing with the ACR.
 

Last edited by jhoffy22; 06-26-2011 at 02:08 AM.
  #139  
Old 06-26-2011 | 02:11 AM
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Originally Posted by bumblebee
So what's the verdict on it?
Do we just ignore it and go ahead with the cam changes?
That's what I'm doing...
 
  #140  
Old 06-26-2011 | 02:16 AM
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Originally Posted by jhoffy22
EDIT: Just re read the original post. I didn't do anything with the ACR. This explains why I have muddy middle range. I am not getting good compression and still have the intake grawl and not enough exhaust. I actually think it got quieter when I just rotated the cam sprocket bolts and did nothing with the ACR.
ACR is only used during starting. It's to hold open an exhaust valve when rpm is below around 500 rpm (someone correct me if I'm wrong). Supposed to relieve stress on the starting system. Once the bike's running, and if the ACR isn't stuck engaged, it should not be a factor at all.
 


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