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FCR39 idling at 6500 rpm

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I've been messing with this for a few days, installed BB, E cams, FCR39 slant. Started and it immediately revs to 6500 rpms and stays there. Idle adjuster is backed all the way out. Adjusted the fuel/air screw from 1 turn to 3 turns. Took off the throttle cables. Took the carb off the boots and made sure the slide was closed. Everything checks out. Jetting at around 500' is 155 main, 45 pilot, EMR needle 3rd clip, 100 PAJ, 200 MAJ, 9mm float height. No CE, O ring mod. I'll post pics below, tell me if I messed something up somehow. Kinda confused why my carb doesn't have the second port for the CE on the intake side 😕 anyone know why? Would this cause an issue? How does one go about testing the squirter? Is there anyway that could be stuck open and is constantly squirting fuel into my engine causing it to rev? Any help is greatly appreciated, I'm completely lost right now.received_275236159927970.thumb.jpeg.63cd617ad741e06b2b340a4b6a764306.jpegreceived_2119921864704689.thumb.jpeg.90b6f9b69ad2128b0148f994eb15c123.jpegreceived_298484777387674.thumb.jpeg.d6dff55d15d6bccec8a7ba8be2c2df58.jpegreceived_831817830354717.thumb.jpeg.7e96a4b61416a5fc239491d4cd516f42.jpeg

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I would triple check your slide moves open and closed when the throttle cable is hooked up as well as checking your needle height, if those are good you might have an air leak as mentioned above, if so get a bottle of soapy water and hook everything up, start it for just a minute and then kill it since the RPMs are so high, look for bubbles in the soapy water to locate the leak. Don't go crazy with the soapy water or running that motor at high RPMs, but this can be an effective troubleshooting method. 

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6 hours ago, ohiodrz400sm said:

High RPM at closed throttle is either a stuck slide or air leak.

Do you know anything about that missing port?

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Took the carb off went thru the entire thing, made sure everything looked good. Reinstalled making sure the boots were sealed well. Still idles at 6000+ rpm.... The pilot jet controls the amount of fuel it gets at idle correct? Maybe the 45 is too big? Although I think that's what ohiodrz400sm said he used

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is it a new to you carb? have you ever ran it on your bike before

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Does it rev like that with the throttle cables unhooked ? For an airleak to allow 6000 rpms it would have to be pretty big , has to be something that should be easily seen like a hot start port open, the slide is closed enough in the picture to snuff it down so air would need to be coming elsewhere if not being hung open with the throttle cable.

 

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14 hours ago, RetroRanger said:

is it a new to you carb? have you ever ran it on your bike before

Never ran on my bike before. It came off a 2000 E

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14 hours ago, jjktmrider said:

Does it rev like that with the throttle cables unhooked ? For an airleak to allow 6000 rpms it would have to be pretty big , has to be something that should be easily seen like a hot start port open, the slide is closed enough in the picture to snuff it down so air would need to be coming elsewhere if not being hung open with the throttle cable.

 

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Yeah throttle cables unhooked. I figured it'd have to be a huge air leak and I'm positive that's not the case. Is something wrong with the jetting? I'm not experienced with tuning carbs so I'm not sure what kind of incorrect jetting would cause high idle

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In your pic of the side with the bolt on snout there is a port up near the top on the backside of the slide "tunnel" that goes straight through to the other side , I see yours are not plugged off . ? Do they have access to the inside by the slide ?  That may be the air intake , common for a hot start plunger to go there and where they introduce air . I'm not real familiar with that particular carb so it may be normal .

 

 

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Edited by jjktmrider

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16 minutes ago, jjktmrider said:

In your pic of the side with the bolt on snout there is a port up near the top on the backside of the slide "tunnel" that goes straight through to the other side , I see yours are not plugged off . ? Do they have access to the inside by the slide ?  That may be the air intake , common for a hot start plunger to go there and where they introduce air . I'm not real familiar with that particular carb so it may be normal .

 

 

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I didnt have any hoses connectted when I took the pictures so there is one vent hole that goes all the way through that would usually have a hose. Other than there there are some random holes that lead to nothing, not sure of their purpose

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41 minutes ago, ohiodrz400sm said:

45 pilot is not causing the problem. Remove the fuel screw and check the condition of the O-ring. Make sure it's assembled correct. The order is spring , washer, o-ring.

Just double checked, the order is correct

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does yellow intake adapter allow air to be sucked through  100 and 200 air jets 

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2 hours ago, ohiodrz400sm said:

Well sh!t. I've been looking for days at hundreds of issues people have had with these carbs and never came across that. Just checked and sure enough, it's upside down since I've been following the oem exploded views on here. 

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Posted (edited)

The bike is NOT idling if it is running at 6500 RPM, nor is it operating on the idle circuit. 6500 RPM is near redline for this bike.

You need to check the slide. I dont think an air leak would take the RPM anywhere near 6500RPM. Also dont think the bike would rev to 6500RPM without the slide open.... Definitely NOT a jetting problem.

Edited by 68lemans462

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