Weird jerking feeling while riding

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Apr 20, 2010 | 08:46 PM

#31

Dr.Hess

Seasoned HDF Member

Joined: Aug 2007

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From: NW AR

Ignition module tests are outlined in detail in the shop manual.

Apr 21, 2010 | 05:56 AM

#32

pjb

Stellar HDF Member

Joined: Apr 2007

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Quote:

Originally Posted by MrFxrs-sp

Is there a way to test the iginition module ?

only good way I know - replace it with a known good one.

Apr 21, 2010 | 10:12 AM

#33

MrFxrs-sp

Thread Starter

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Joined: Apr 2010

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From: Youngstown

The bike is getting a sputtering or miss at higher rpms now.
Changed battery and it still does it. Should my next step be a coil ?
Then IM .. ??

Apr 21, 2010 | 11:13 AM

#34

t150vej

HDF Community Team

Joined: Dec 2005

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From: NC USA

Quote:

Originally Posted by MrFxrs-sp

The bike is getting a sputtering or miss at higher rpms now.
Changed battery and it still does it. Should my next step be a coil ?
Then IM .. ??

Early on in this thread, myself as well as others, may have assumed it was a hard jerk of the entire bike, rather than a mild stumble feeling you may have tried to communicate. An ignition module will either work or it won't. A coil will act up intermittently but generally causes hard starting and/or shuts off. The pickup in the nose cone can act up from becoming heat sensitive or the leads from it to the module can become compromised.

From the symptoms you've expressed latley, I'm beginning to think you may have a very lean condition. Of course the new intake gaskets would have been a big improvement, but a CV carb that has had the slide drilled, a Thunderslide with improperly set needle and regardless, if it's jetted too lean, a leaking diaphram, float level set way low... any of those things will make one very irregular anywhere near steady crusing speeds.

Obviously without riding it or near it, I can't tell you the exactly what to do, but I think ensuring the carb isn't the culprit would be the next logical
step... you'd need to take the bowl off and see what size jets it has and remove the top and pull the diaphram to check on that or use a small inspection mirror to look at the vacuum hole in the bottom of the slide to see if it's been drilled. If it looks like a 1/8" hole it's been "doctored" (no offense Hess) and I don't know the exact size of the original drilling, but it's about 5/64" or 2mm

Apr 21, 2010 | 11:21 AM

#35

MrFxrs-sp

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Joined: Apr 2010

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From: Youngstown

The carb is running rich now that the seals are replaced.

Its hard to explain whats going on but I will try to describe it a little better then what I did last time.

Firsr off The plugs and wires have been replaced. The air filter has been replaced. and now the battery has been replaced. It was bad.

The bike starts up ok.
Its not a smooth idle it kind of pops then goes back to a smooth idle then it goes back to popping again. Which to me sounds like its missing every once in awhile.

Then in gear it rides ok at first. Then it will start jerking and sputtering.
Then at high rpm it sounds like a miss and then it picks up and sputters then runs ok for a little bit then does it again. If you let off the it almost wants to stall out. Give it some more power and it goes again.

I ordered a new coil since I dont know how long this ones has been on here. That should be here this weekend I hope.

I have also pulled on the wires while the bike was idling and it didnt help or cause the problem so I dont think theres a broken wire anywhere..

Things that I am going to check later.
Ground wire. and that coil.

Thanks!!

Apr 21, 2010 | 11:59 AM

#36

t150vej

HDF Community Team

Joined: Dec 2005

Posts: 5,402

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From: NC USA

Quote:

Originally Posted by MrFxrs-sp

Then in gear it rides ok at first. Then it will start jerking and sputtering.
Then at high rpm it sounds like a miss and then it picks up and sputters then runs ok for a little bit then does it again. If you let off the it almost wants to stall out. Give it some more power and it goes again.

That does sound a lot like a coil going out, especially that you have to keep it reved to keep it running (when it's acting up) There are ohm tests for the coil, though that won't always reveal a bad one. With an ohm meter across the primary (little posts) it should read about 2.5 - 3.5 ohms. Across the plug terminals is should be in the 11K - 15K readings.

Wires coming off the timing pickup can get broken (even inside the insulation and hard to pinpoint) and cause all kinds of intermittent probs too. But try your new coil and we'll hope that does it

By the way, a weak coil/spark can make one appear to be rich also...

More than few guys have solved all kinds of problems by simply replacing the ignition breaker. Certainly the wire terminals need to be clean and snug and the same goes for the coil. More than a few have pulled out their hair only to finally find a bad terminal at the coil. And you may have already done this, but by all means check your charging voltage. When a stator is going out, they will often charge just fine when cold but stop charging when the bike gets warm. Just after a ride, put a voltmeter on the battery or anywhere easy and rev it up. You should get 14 volts or better.

The wires coming out of the nose cone will drive you nuts sometimes. Like I mentioned, they'll get nearly broken inside the insulation where you can't see, make contact enough to run OK for a while then get hot and start breaking the circuit just enough to make one miss and skip.

Last edited by t150vej; Apr 21, 2010 at 04:13 PM.

Apr 21, 2010 | 04:24 PM

#37

Dan89FLSTC

Seasoned HDF Member

Joined: May 2008

Posts: 21,131

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From: South Carolina

Before you start buying parts, make sure the carburetor is clean.

Apr 22, 2010 | 07:26 AM

#38

Hackd

Elite HDF Member

Joined: Oct 2005

Posts: 3,872

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From: Canton, Michigan

If your indy has a dyno (and knows how to use it), pay for some time and have him run the bike on it. Any problems should show up and be easily identified, rather than throwing $100 bills at it hoping to correct them at the present stage.