Sighs and takes deep breath (Carb tuning help)

3rdgearpinned
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In the Mountains, NC, USA
Guys,

There are 6 billion topics on this but I just cant find one that pertains to my bike. I bought a 2000 CR125 beater to trail ride with on the cheap. I did all the mechanical and electrical so I wouldnt have to push it lol. Heres the deal.

Crank had 20 hours on it
Put new piston and ring in it.
JD jet kit (waste of money but hindsite is 20/20)
New Coil
I went back to all stock jets for it except for the needle. So I think the main jet is 350.

Symptoms: I have good smoke, not excessive. She Fouled plug #1 in 39 minutes. I made no adjustments and the 2nd one last 90 minutes. I felt like even tho I had good smoke, that yes, its fouling plugs, it felt a bit lean and the pipe hot. You couldnt hold your hand on it with a thin glove on at the fattest part. Tight trails, first and second gear but every chance I was on the pipe hard.

The air fuel was 4 turns out from the normal 1.5 to 2 so, since it was still fouling I added more air just to see. I know that is way to far out so I need to step down on the main jet but Im in the woods with no jets so Im trying things.

I added more air/fuel mixture and plug 3 only lasted 20 minutes. All of the fouled plugs were same color upon removal, darker and a thin coating of oil/gas not sloppy but the insulation around the tip was black. So, is there a possibility of a HOT foul? Was this thing too lean after all?


Some things you may ask:

Have you replaced crank seals?
Yes, both sides

Have you set the float bowl? Yes, level by eye only tho.


What clip is the needle on?:
Top Clip (was spooging hard after new piston)

What size main Jet? I removed the suggested 390 from JD and went back to the one that I assume is factory (350) from honda

Air/Fuel Mixture Screw?
4 turns out

Pilot? Factory Honda


Wrap up:

I am thinking about just starting over with all factory settings but I felt like I had it there right after rebuild and it was spooging lots of unburned oil out of the header. I have finally gotten that alot better but now that pipe is pretty hot and tho I have some smoke all the way through the throttle (most at WOT) Im wondering if the plug is getting too hot and just fouling because of the heat? They really dont look fouled to me.

Thanks for the time guys, just wondering.
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9/12/2016 8:36am
only thing I had close to this was a 65 that would run nice and strong for a practice but when taken to the gate for a race wouldn't start. plugs always came out a little wet but not bad looking. everyone told me it was the ignition box. I resisted thinking no way cause with a new plug it ran great.
when I finally gave in and bought a new box it fixed the problem.,

my unsubstantiated guess would be you have a weak spark allowing the plug to get wet and foul. the hot pipe is from you turning the air screw out 4 turns. I think back to stock setting and a new box would get running correctly then go to the recommended JD setting/jets.

down side the box is just a guess.
Frodad78
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9/12/2016 10:26am
I had that same bike and the carb jetting was always a mess. I finally put a PWK airstriker on it and that was that. Still have the carb.

How is the bike running power wise? Is it blubbery off the bottom? is it loading up to the point where you have to blow it out? Lack of power anywhere?

Is your Powervalve assembly installed correctly? Its really easy to mess it up if you do'nt have the manual handy.

My CR ran like shit and I pulled it apart and found the Powervalve was stuck closed due to the PO.
3rdgearpinned
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In the Mountains, NC, USA
9/12/2016 10:31am
Frodad78 wrote:
I had that same bike and the carb jetting was always a mess. I finally put a PWK airstriker on it and that was that. Still...
I had that same bike and the carb jetting was always a mess. I finally put a PWK airstriker on it and that was that. Still have the carb.

How is the bike running power wise? Is it blubbery off the bottom? is it loading up to the point where you have to blow it out? Lack of power anywhere?

Is your Powervalve assembly installed correctly? Its really easy to mess it up if you do'nt have the manual handy.

My CR ran like shit and I pulled it apart and found the Powervalve was stuck closed due to the PO.
It has great power all over low to high. The power valve was cleaned and I inspected and re installed the power valve myself. I know it's correct. I have thought about the airstryker bu I wanted to make sure this one was the problem first.
pete24
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Marlborough, MA, USA
9/12/2016 10:56am
buy this and put it in , i do a lot of honda two strokes and the oring is worn out and leaking fuel buy, and fouling your plug, when i figured it out i did everything you could think of, including doing the entire motor over , crank included so i would know exactly what i had, this is what you need if it doenst work ill pay you for the part

16012-KZ4-A92

The Shop

3rdgearpinned
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9/12/2016 11:03am
pete24 wrote:
buy this and put it in , i do a lot of honda two strokes and the oring is worn out and leaking fuel buy, and...
buy this and put it in , i do a lot of honda two strokes and the oring is worn out and leaking fuel buy, and fouling your plug, when i figured it out i did everything you could think of, including doing the entire motor over , crank included so i would know exactly what i had, this is what you need if it doenst work ill pay you for the part

16012-KZ4-A92
for $5 i certainly will. Maybe as well the complete moose carb rebuild kit.
Paw Paw
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9/12/2016 2:30pm
I did not see any where that you checked or set the float height.
I also would be thinking about the crank seals.

Paw Paw
3rdgearpinned
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9/12/2016 2:42pm
Paw Paw wrote:
I did not see any where that you checked or set the float height.
I also would be thinking about the crank seals.

Paw Paw
Yes paw paw. I put new seals in both sides and leveled the float with the carb upside down. I had to do it by eye tho.
pete24
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9/12/2016 3:29pm
do not buy the chineese moose part buy the oe honda part
captmoto
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9/12/2016 4:35pm
Oil side crank seal leak maybe? On my 250 the seal had somehow backed out over half way and started to suck more and more oil.
3rdgearpinned
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9/12/2016 4:51pm Edited Date/Time 9/12/2016 4:52pm
captmoto wrote:
Oil side crank seal leak maybe? On my 250 the seal had somehow backed out over half way and started to suck more and more oil.
Yep both new. Forgot to add that. Thanks for the reply!

I just ordered a slew of OEM jets and pilot. Gonna go back to the grass roots and start.
Markee
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Suffolk, VA, USA
9/12/2016 6:02pm
Frodad78 wrote:
I had that same bike and the carb jetting was always a mess. I finally put a PWK airstriker on it and that was that. Still...
I had that same bike and the carb jetting was always a mess. I finally put a PWK airstriker on it and that was that. Still have the carb.

How is the bike running power wise? Is it blubbery off the bottom? is it loading up to the point where you have to blow it out? Lack of power anywhere?

Is your Powervalve assembly installed correctly? Its really easy to mess it up if you do'nt have the manual handy.

My CR ran like shit and I pulled it apart and found the Powervalve was stuck closed due to the PO.
My buddy had a similar problem and he tried every setup possible. I said "man chunk the carb and get a new one, i'm sick of this shit hearing about it every ride" PWK problem solved.
Frodad78
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9/13/2016 6:58am
Markee wrote:
My buddy had a similar problem and he tried every setup possible. I said "man chunk the carb and get a new one, i'm sick of...
My buddy had a similar problem and he tried every setup possible. I said "man chunk the carb and get a new one, i'm sick of this shit hearing about it every ride" PWK problem solved.
Exactly, probably spent 200 bucks rebuilding a PWK, sold the bike but now I can't sell the damn carb. lol
3rdgearpinned
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9/13/2016 7:06am
Markee wrote:
My buddy had a similar problem and he tried every setup possible. I said "man chunk the carb and get a new one, i'm sick of...
My buddy had a similar problem and he tried every setup possible. I said "man chunk the carb and get a new one, i'm sick of this shit hearing about it every ride" PWK problem solved.
Frodad78 wrote:
Exactly, probably spent 200 bucks rebuilding a PWK, sold the bike but now I can't sell the damn carb. lol
U still have the pwk or is it the stock one you are talking about?
Frodad78
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9/13/2016 10:28am
U still have the pwk or is it the stock one you are talking about?
I still have the PWK. Figured it was worth holding on to.
9/13/2016 10:46am Edited Date/Time 9/13/2016 10:46am
Is it the long or short body airstriker?
I'm interested, alexanderlindahl91 at gmail.com
Frodad78
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9/13/2016 10:49am


Frodad78
Posts
2155
Joined
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Location
USA
9/13/2016 12:06pm
Is it the long or short body airstriker?
I'm interested, alexanderlindahl91 at gmail.com
Mail sent
PRM31
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Fantasy
9/15/2016 10:13am
If you're fouling plugs, you're rich. What were the JD Jetting jets vs. OEM? I'd trust the JD, or find if something else is wrong. How are the reeds? Filter not plugged with too much oil?

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