Engine Stumbling, Cutting Out
Thread Starter
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Novice
Joined: Aug 2022
Posts: 15
Likes: 1
From: Port Saint John, Florida
Engine Stumbling, Cutting Out
Hello All-
I recently joined this forum and I thank you all for allowing me to post my questions and comments..
I purchased a1999 XL883C Sportster with the Screamin Eagle Heads and who knows what else. I do know it has a Mikuni Carb. The original Screamin Eagle Ignition Module was replaced by a mechanic with a Dyna S. Supposedly, the engine was timed after the installation. Also the engine/transmission oil was changed and a new Speed Sensor installed.
I have not had anytime to get it out on the highways since I purchased it so today I took a 3 hour trip at interstate state speeds. As long as I am cruising at 70 MPH, all seems well until I slow down to around 50 and then resume back to 70. If i twist the throttle slowly, all is well, but if I gun it hard the engine will stumble (cut out) and then recover. I have found this to be the case even as slower speeds.
There is no starting or idle issue and no unexpected engine shutdowns. The air filter is clean. I did notice my choke had inched it way out slightly but resetting it had no effect on improving the engine performance.
So here I am, new to the Harley Davidson brand and confronted with this issue. If anyone can steer me in the right direction to correct this problem, I would sincerely appreciate it.
I recently joined this forum and I thank you all for allowing me to post my questions and comments..
I purchased a1999 XL883C Sportster with the Screamin Eagle Heads and who knows what else. I do know it has a Mikuni Carb. The original Screamin Eagle Ignition Module was replaced by a mechanic with a Dyna S. Supposedly, the engine was timed after the installation. Also the engine/transmission oil was changed and a new Speed Sensor installed.
I have not had anytime to get it out on the highways since I purchased it so today I took a 3 hour trip at interstate state speeds. As long as I am cruising at 70 MPH, all seems well until I slow down to around 50 and then resume back to 70. If i twist the throttle slowly, all is well, but if I gun it hard the engine will stumble (cut out) and then recover. I have found this to be the case even as slower speeds.
There is no starting or idle issue and no unexpected engine shutdowns. The air filter is clean. I did notice my choke had inched it way out slightly but resetting it had no effect on improving the engine performance.
So here I am, new to the Harley Davidson brand and confronted with this issue. If anyone can steer me in the right direction to correct this problem, I would sincerely appreciate it.
Thread Starter
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Novice
Joined: Aug 2022
Posts: 15
Likes: 1
From: Port Saint John, Florida
Here I am again. Engine still stumbling and cutting out as before. Here's what I have done so far to troubleshoot 1) Clean gasoline 2) Cleaned the HSR42 Mikuni Carb 3) Installed a smaller size acceleration pump nozzle. Went back to the original because it did not help 4) Static timed the Dyna S ignition module 5) Check VOES No Issues 6) Checked Coil. Reads 3.0 ohms Primary 11k ohms Seondary. 7) Replaced petcock and filter strainer with a non vacuum type. Plugged original petcock vacuum hose. 8) Relocated spark plugs from top of the heads to the sides (Screamin Eagle Four Plug) heads. Replaced spark plugs. 9) Raw adjusted timing while test riding. No appreciable change noted. 10) Adjusted the hell out of the accelertor pump. No difference.
Tonight i am going to have the battery
Load Tested but I do not think there
is anything wrong with it, but who
knows.
Anyone out there have any suggestions?
Tonight i am going to have the battery
Load Tested but I do not think there
is anything wrong with it, but who
knows.
Anyone out there have any suggestions?
Seasoned HDF Member
Joined: Apr 2011
Posts: 6,185
Likes: 2,134
From: W. Texas
I fought a symptom much as you describe for a good while. Months
It ended up needing the float level raised to the highest spec.
In re cking everything after being in the carb 3-4 times I just gave it try. That fixed it
I'll mention this was CV rather than a Mikuni.
Good Luck WP
It ended up needing the float level raised to the highest spec.
In re cking everything after being in the carb 3-4 times I just gave it try. That fixed it
I'll mention this was CV rather than a Mikuni.
Good Luck WP
Thread Starter
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Novice
Joined: Aug 2022
Posts: 15
Likes: 1
From: Port Saint John, Florida
No Drag Pipes. I left out the part where I adjusted the float level. Raised the level enough where the fuel was leaking out the over flow and then I lowered the level. No joy.
Thread Starter
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Novice
Joined: Aug 2022
Posts: 15
Likes: 1
From: Port Saint John, Florida
Forgot to add, this bike is a 1999 XL883C "Screamin Eagle" bored to a 1200, Mikuni Carb, Dyna S Ignition, Single Fire Screamin Eagle Coil. Standard Mikuni Factory Jets and Accelerator Nozzle (Main Jet 160; Pilot Jet 20; Accelerator Nozzle 50) Jet Needle 97 and is adjusted on the #3 clip position.
This monster has been a pain in the *** since I bought it but I am up to the challenge.
This monster has been a pain in the *** since I bought it but I am up to the challenge.
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Thread Starter
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Novice
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From: Port Saint John, Florida
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Joined: Jan 2009
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From: Ottawa, Ontario
Originally Posted by TnRabbleRouser
... bike is a 1999 XL883C "Screamin Eagle" bored to a 1200...
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