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Officially stumped...

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Shawn,

How is the compression? Weak compression will give the signs of a rich condition.

1% leak down with a 13.5:1 piston...

compression = buttloads

have you ever seen the vacuum release plate wear out? Seems like this one is very tight around the seat and not very tall off the plate...but it does hold the plate up off the slide body just slightly, maybe .010"

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Man......I'd really try to find another carb and swap it out.

If you were closer I'd let you throw my carb on there.

You said it's got head work, I bet that's playing with the carb settings a little more than you think.

Who ported it?

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Adams apple is the first check! You must be on the same e mail list as I:p

Shawn:

Stupid question #1: Is the vacuum plate upside down?

Stupid question # 2: Did you use a degree wheel and solid stop to check the lobe centers?🙂

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Man......I'd really try to find another carb and swap it out.

If you were closer I'd let you throw my carb on there.

You said it's got head work, I bet that's playing with the carb settings a little more than you think.

Who ported it?

I did. All I did was clean up the bowls. Basically blended the seats into the bowls. I didnt remove any material from the cross section or the roof. I didnt even blend the guide bosses.

I'll swap the carb off my 03 to it tomorrow. See what that yields. If I end up in the same place Im going to retard the cam timing a tooth from where it is.

I'll tell ya this though, with the Primary Air jet out and the fuel screw all the way in, the thing repsonded to the throttle like a Top Fuel Funny Car! 👍

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Adams apple is the first check! You must be on the same e mail list as I:p

Shawn:

Stupid question #1: Is the vacuum plate upside down?

Stupid question # 2: Did you use a degree wheel and solid stop to check the lobe centers?👍

Nope, vacuum plate is correct. Yup, I degreed the cam and its dead nuts too.

So I started looking at the carb again...and started doing some wierd shit...

I took the choke plunger out while it was running and it died.

I purposely plugged the pilot jet and it had zero effect on how the bike runs and idles. So now Im really stumped. Where in Gods name is this thing pulling fuel from. It almost certainly has to be the main circuit, but its perfect upon inspection. Unless Im just missing something entirely... :worthy:

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I know this maybe a silly question, but what type of fuel are you running with that high comp piston and cams?

On all our mod bikes we run nothing less then 104 when the comp is 13.5:1

You can lean the bike out with higher octane fuel.

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I know this maybe a silly question, but what type of fuel are you running with that high comp piston and cams?

On all our mod bikes we run nothing less then 104 when the comp is 13.5:1

You can lean the bike out with higher octane fuel.

I wish I could get the thing lean!! :worthy:

It is pulling fuel from someplace other than the pilot circuit. Thats what I cant figure out.

The choke seems to be working properly. The hotstart almost works like the damn throttle this thing is so rich, and thats with the fuel screw all the way in, the Primary air jet clear out of the carb and the pilot jet purposely plugged up with a piece of paper.

Im missing something...gotta be...this isnt making any sense... 👍

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Check out the thread I started last year. https://thumpertalk.com/forum/showthread.php?t=578293 My needle was worn .001 inch. You cannot see the wear, you have to measure it. The wear on the needle dictates what part of the throttle opening is affected. Mine ran very rich just off of idle. If the needle is worn then the needle holder is worn too. REplace them both. Good luck, Brian

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could be bad checkvalve letting fuel going through acc pump nozzle only while running

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For around $25 I would try changing the needle and needle jet holder like Blackie107 said. I've cured 3 different bikes idling issues with this simple fix. It will pull fuel through this circuit at idle with a loose fitting needle.

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i replied to your pm,but i will post it here.

the needle jet is worn out.pretty common.

i think they are less than $20 from honda.

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For around $25 I would try changing the needle and needle jet holder like Blackie107 said. I've cured 3 different bikes idling issues with this simple fix. It will pull fuel through this circuit at idle with a loose fitting needle.

Go back up and look at my first post...👍

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Go back up and look at my first post...:doh:

Wow..its cured.

The difference between his needle and the one that works; .0003" 😛

Thats 3 ten-thousandths of an inch. Or about half the oil clearance on the wrist pin...

I cant measure the inside of the needle jet holder, but Im replacing both with new. :busted:

I have to assume there is wear inside the needle jet holder that I cant measure. Simply changing that out to a known good part made a significant difference. Then changing the needle cleared the problem entirely. :blah:

I cant hardly even wrap my brain around that tiny difference being able to completely overcome the pilot jet and fuel screw. :D:worthy:

Oh well, I'll sleep better tonight.... 👍

And sorry for being such a damn knot head about looking at the needle and needle/jet holder. This is one of those tuning tips you never ever forget!🤣

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Hoo Rah !

Thanks for telling us what fixed the problem. I guess this proves how important this forum is. Sleep well.

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Wow..its cured.

The difference between his needle and the one that works; .0003" 😛

Thats 3 ten-thousandths of an inch. Or about half the oil clearance on the wrist pin...

I cant measure the inside of the needle jet holder, but Im replacing both with new. :busted:

I have to assume there is wear inside the needle jet holder that I cant measure. Simply changing that out to a known good part made a significant difference. Then changing the needle cleared the problem entirely. :blah:

I cant hardly even wrap my brain around that tiny difference being able to completely overcome the pilot jet and fuel screw. :doh::worthy:

Oh well, I'll sleep better tonight.... 👍

And sorry for being such a damn knot head about looking at the needle and needle/jet holder. This is one of those tuning tips you never ever forget!🤣

that is strange.....never heard of that happening before:excuseme: ....makes me wanna check my 03's jd needle compared to wait.....i have the stock needle still with maybe 30 hrs on it :D

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Would have taken me forever and a bottle of Valium to figure that one out...

Nice job!

👍

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i get bikes from all over the country that owners give up and just bring the bike to me.

some of them have taken them to multiple shops.

its a common deal.

ive also found more than one "race tuner" that thinks drilling the needle jet is the cure for a bog.

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