hesitation
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Joined: Aug 2014
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From: Upstate NY
hesitation
1984 FRXP has serious hesitation when rolling throttle just coming off idle rpms. It dogs down then jumps into action. Fuel or electric problem? Also while cruising along and rolling thottle to go faster sounds like pinging or spark knock. Using fresh, regular octane gas. Fuel or electric? Thanks for any suggestions, gregjo1948
Road Warrior
Joined: Oct 2011
Posts: 1,376
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From: Round Rock, TX
First I'd attack the pinging, which can be damaging. Check and set the timing and make sure the VOES is operational. If the engine has been modified and compression increased, you may find you'll need to run premium, but make sure the timing and advance are to spec first.
If you get that solved, and the hesitation is still there, it's probably time to go into the carb, or just replace it if it's an original butterfly carb.
If you get that solved, and the hesitation is still there, it's probably time to go into the carb, or just replace it if it's an original butterfly carb.
Road Master
Joined: Jan 2012
Posts: 856
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From: North Carolina
I have always been told to run only premium gas in a Harley. I suspect regular gas could be your problem. I can't speak from experience since I have never run regular gas in my bikes. Pinging is a common symptom of not having enough octane in your gas. Lower octane gas burns faster and can pre-ignite in the cylinder which is a ping. The gas burns before the piston hits TDC. It is real bad for your engine. Run the best gas you can get at all times and a lot of your problems will go away. I have owned a bunch of bikes and the only ones I ever ran regular gas in were GoldWings because they are tuned for that.
Also, an intake leak will often cause a lower rpm studder. Check for a leak around the intake to head seals. Could be some trash in the low speed circuit in the carb too. Personally, I would suspect electrical after carb on this type issue.
Also, an intake leak will often cause a lower rpm studder. Check for a leak around the intake to head seals. Could be some trash in the low speed circuit in the carb too. Personally, I would suspect electrical after carb on this type issue.
Last edited by falconbrother; Sep 8, 2014 at 08:47 AM.
Seasoned HDF Member
Joined: Jun 2010
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From: Upstate New York
As has been mentioned, check the operation of the VOES. The rubber diaphragm and switch don't last forever. I found out last year, when my VOE switch went bad. The bike suddenly began pinging badly.
A ruptured diaphragm on the VOES will not only cause pinging or poor running, it will also create a vacuum leak, because it IS a vacuum leak.
A ruptured diaphragm on the VOES will not only cause pinging or poor running, it will also create a vacuum leak, because it IS a vacuum leak.
Road Master
Joined: Oct 2011
Posts: 957
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From: Carlsbad Springs Ontario
hesitation and pinging.
1984 FRXP has serious hesitation when rolling throttle just coming off idle rpms. It dogs down then jumps into action. Fuel or electric problem? Also while cruising along and rolling thottle to go faster sounds like pinging or spark knock. Using fresh, regular octane gas. Fuel or electric? Thanks for any suggestions, gregjo1948
As for voes. switch ... check the electrical connectors first then check for switch operation with a vacume pump . Switch should activate between 3-5 inches of mercury . OR just suck on the switch with you mouth to ensure that it is operating and holding vacume etc.
If it dosent switch or hold vacume , replace the voes.
Come back with your findings.
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Joined: Aug 2014
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From: Upstate NY
My first thought is to add some fuel cleaner to the gas to clean out a possible clogged jet .
As for voes. switch ... check the electrical connectors first then check for switch operation with a vacume pump . Switch should activate between 3-5 inches of mercury . OR just suck on the switch with you mouth to ensure that it is operating and holding vacume etc.
If it dosent switch or hold vacume , replace the voes.
Come back with your findings.
As for voes. switch ... check the electrical connectors first then check for switch operation with a vacume pump . Switch should activate between 3-5 inches of mercury . OR just suck on the switch with you mouth to ensure that it is operating and holding vacume etc.
If it dosent switch or hold vacume , replace the voes.
Come back with your findings.
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Tourer
Joined: Mar 2014
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From: Idaho
Not sure if you are kidding about the oral sucking but, I tried it anyways. Not sure what it's suppose to do. I sucked on it, blew on it, cuddled it and it did nothing with the switch on or off. Should I be able to feel anything holding it and turning on the switch? I have a good repair manual but it doesn't say what this thing does or how it functions. Perhaps you could enlighten me? Thanks, gregjo1948
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Road Master
Joined: Oct 2011
Posts: 957
Likes: 2
From: Carlsbad Springs Ontario
oral.
Not sure if you are kidding about the oral sucking but, I tried it anyways. Not sure what it's suppose to do. I sucked on it, blew on it, cuddled it and it did nothing with the switch on or off. Should I be able to feel anything holding it and turning on the switch? I have a good repair manual but it doesn't say what this thing does or how it functions. Perhaps you could enlighten me? Thanks, gregjo1948
The Voes. switch is a simple " on/off " switch that is activated by vacume produced by the carb.
To test the Voes. switch you would connect a mutimeter set to continuity to the two wires on the Voes. switch.
You then apply a vacume to the Voes. hose by mouth or by the above mentioned vac. pump.
You are now looking for results of this test.
1) when you sucked on the hose did you hear a click from the voes. and did the meter read continuity ?
If ok this tells you that the electrical switch in the voes. is ok.
2) suck on the hose and try to detect if the vacume is steady or is deteriorating over a few seconds. Use your tounge as a stop valve.
If you find that the vacume is deteriorating , this means that the diaphram in the voes. is punctured and is leaking air.
Experiment with this process for a minute or two to get the feel of it .
This works to diagnose a Voes , take it or leave it from an older Bro.
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Joined: Aug 2014
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From: Upstate NY
Lol ... Yes bud , im serious . The mouth thing is to do if you dont have the expensive hand held vacume pump that most dudes dont have in there garage tools.
The Voes. switch is a simple " on/off " switch that is activated by vacume produced by the carb.
To test the Voes. switch you would connect a mutimeter set to continuity to the two wires on the Voes. switch.
You then apply a vacume to the Voes. hose by mouth or by the above mentioned vac. pump.
You are now looking for results of this test.
1) when you sucked on the hose did you hear a click from the voes. and did the meter read continuity ?
If ok this tells you that the electrical switch in the voes. is ok.
2) suck on the hose and try to detect if the vacume is steady or is deteriorating over a few seconds. Use your tounge as a stop valve.
If you find that the vacume is deteriorating , this means that the diaphram in the voes. is punctured and is leaking air.
Experiment with this process for a minute or two to get the feel of it .
This works to diagnose a Voes , take it or leave it from an older Bro.
The Voes. switch is a simple " on/off " switch that is activated by vacume produced by the carb.
To test the Voes. switch you would connect a mutimeter set to continuity to the two wires on the Voes. switch.
You then apply a vacume to the Voes. hose by mouth or by the above mentioned vac. pump.
You are now looking for results of this test.
1) when you sucked on the hose did you hear a click from the voes. and did the meter read continuity ?
If ok this tells you that the electrical switch in the voes. is ok.
2) suck on the hose and try to detect if the vacume is steady or is deteriorating over a few seconds. Use your tounge as a stop valve.
If you find that the vacume is deteriorating , this means that the diaphram in the voes. is punctured and is leaking air.
Experiment with this process for a minute or two to get the feel of it .
This works to diagnose a Voes , take it or leave it from an older Bro.