Ignition questions...

Energy One
Mods, feel free to move this to the "Vintage" forum if that's where it'd be more appropriate, but I have some questions about the ignition setup on my 1999 Vintage Sport with S&S 107 and Thunder Heart dual-fire ignition. After having to seek the help of my local V-Twin guru (we both thought the problem was ignition-related, turns out the main jet of my carb literally fell out and was sitting in the bottom of my float bowl!?) to deal with very crappy throttle response, he was telling me that he'd had a lot customers that had come in to replace the Thunder Heart ignition systems on their bikes. He hadn't done much with Big Dogs, but they were apparently a fairly common part used when the "chopper craze" of 10-15 years ago was in its heyday. He suggested that I swap over to the Crane/S&S HI-4N setup in single-fire mode for best performance. I like to do most of my work myself when I'm able, because I want to know what's going on with my bike and don't like shelling out for labor if I can do it myself, so I'll be putting it in. That said, I need to know a few things.

A) Is there anything specific that I need to do with the old Thunder Heart ignition module, i.e. is it controlling anything else that needs to be converted/retrofitted?

B) Is there a single-fire coil that will fit under the original factory billet coil cover?

C) Aside from a 2-into-1 pipe to replace the Hooker Header longshots, the engine is as-built from the factory. What should the rev limiter be set at?
 

Ribs

Live Free & Ride Hard
Well after some time and grounding the neg coil lead to the frame the bike would start so I figured out that my 2000 BullDog Had a bad Ignition coil. After a few minutes or less it just stopped running.
And if i tried to restart it it would just kick over and over. Not gud i was thinking it was a fuel issue. NOT

I went and ordered a coil from S&S but it was way too big to fit under the billet cover. so i ordered a Blue Streak Coil from J&P Cycles
item #380-980 Still a bit big but do able.
Had to use some nolathane spacers so the coil would sit flat to get the slightly longer bolts that i used as the original ones were now too short.

I could not see a + or - symbol on the coil and no instructions of course , so i new the single wire on one side was the neg and the terminal with two wires was the pos
and plugged the leads in keeping the orientation and bolted it all up and to my amazement the thing started instantly i checked to see if both cylinders were firing and they were both getting warm at the same time. idling like a champ.

Once warmed up i revved it a few times and it was running beautiful,

Also I finally took y'all s advise and got the Progressive shocks with RAP ,,,, will finally be able to take the Big Dog out tomorrow.

I hope some how this may help your situation HellOnWheels if you need a pic i can get you one let us know.

Ribs
 

Th3InfamousI

Administrator
Staff member
Well after some time and grounding the neg coil lead to the frame the bike would start so I figured out that my 2000 BullDog Had a bad Ignition coil. After a few minutes or less it just stopped running.
And if i tried to restart it it would just kick over and over. Not gud i was thinking it was a fuel issue. NOT

I went and ordered a coil from S&S but it was way too big to fit under the billet cover. so i ordered a Blue Streak Coil from J&P Cycles
item #380-980 Still a bit big but do able.
Had to use some nolathane spacers so the coil would sit flat to get the slightly longer bolts that i used as the original ones were now too short.

I could not see a + or - symbol on the coil and no instructions of course , so i new the single wire on one side was the neg and the terminal with two wires was the pos
and plugged the leads in keeping the orientation and bolted it all up and to my amazement the thing started instantly i checked to see if both cylinders were firing and they were both getting warm at the same time. idling like a champ.

Once warmed up i revved it a few times and it was running beautiful,

Also I finally took y'all s advise and got the Progressive shocks with RAP ,,,, will finally be able to take the Big Dog out tomorrow.

I hope some how this may help your situation HellOnWheels if you need a pic i can get you one let us know.

Ribs
Did you get those shocks installed already? That RAP thing looks like it will be a big benefit.

Wish I could fit them on the newer dogs

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Ribs

Live Free & Ride Hard
Hi ,, Yes i got the Progressives installed and the only thing about the RAP adjuster is that it's painted black so when i get the Chopper running properly ill look into getting the RAP adjuster either in chrome or get it chromed.

Well Im now having issues with the ignition the bike will start sometimes and will run fine then it will just die. then not want to start again.
then maybe a hour or more or even a day later it will start again you can see what i mean, i thought it was just getting flooded ,, not so . I

have changed the ignition coil to the blue streak coil wired it up as best i could to keep the same orientation and it started straight up thought i had it fixed,, rode it around the yard for a bit them took it down the road and back,, i got back and was letting it idle and it died again.

Tried to start it again and the same thing nothing... tried checking for spark NO SPARK...

When i use to turn the ignition on i use to get a red light next to that plug under the dash housing. now that light does not come on when i turn the ignition on??? do i need to change out the ignition? if so which one would be the simplest and cheapest at this stage i just want to ride the F-----thing thanks in advance.

I also checked the spark plug leads and there not faulty

And when i turn on the ignition the thunder heart does not light up with any error lights as it said it will if there was a error.

Ribs

2000 BigDog Bull Dog
 
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Butch Cassidy

Active Member
Hi ,, Yes i got the Progressives installed and the only thing about the RAP adjuster is that it's painted black so when i get the Chopper running properly ill look into getting the RAP adjuster either in chrome or get it chromed.

Well Im now having issues with the ignition the bike will start sometimes and will run fine then it will just die. then not want to start again.
then maybe a hour or more or even a day later it will start again you can see what i mean, i touhgt it was judt getting flooded ,, not so . I

have changed the ignition coil to the blue streak coil wired it up as best i could to keep the same orientation and it started straight up thought i had it fixed,, rode it around the yard for a bit them took it down the road and back,, i got back and was letting it idle and it died again.

Tried to start it again and the same thing nothing... tried checking for spark NO SPARK...

When i use to turn the ignition on i use to get a red light next to that plug under the dash housing. now that light does not come on when i turn the ignition on??? do i need to change out the ignition? if so which one would be the simplest and cheapest at this stage i just want to ride the F---------thing thanks in advance.

Ribs

2000 BigDog Bull Dog
... check all your grounding wires..... actually PULL on them to make sure of a good connection and with no corrosion.
... some plug wires can 'go bad' and look perfectly fine.... the graphite in them separates or something.....
... again; check all your grounding wires ...................
 

Ribs

Live Free & Ride Hard
... check all your grounding wires..... actually PULL on them to make sure of a good connection and with no corrosion.
... some plug wires can 'go bad' and look perfectly fine.... the graphite in them separates or something.....
... again; check all your grounding wires ...................
ok i will because it seems very peculiar that one min it runs like a scalded dog and then it dies like the cord has been cut and it does not want to start again.

i will check the grounds at least the ones that i can find,, are there any in particular that i need to look for and check ?

I ohm ed out the old ignition coil and it seemed fine so the coil was not the issue.

I also tested the spark plug leads with multimeter and was moving them and tugging on them with no open circuit detected so there OK.

Will go threw the bike and check all grounds really well...

the bike is getting fuel cause i took off the cover and it sprays fuel into the engine no problems ,,, when that bike gets spark it starts instantly. and that is not happening. i will check it thoroughly tomorrow thanks Butch
 
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Ribs

Live Free & Ride Hard
Did you get those shocks installed already? That RAP thing looks like it will be a big benefit.

Wish I could fit them on the newer dogs

Sent from my 2PS64 using Tapatalk
Yeah i actually had to set the RAP to the softest setting and it feels really good, the preset i did not even touch as the bike moved about a inch to a inch and half so the preset seems good.

When i did get a chance to ride it down the road i was hammering it and it handled really nice. cant wait to get this ignition issue sorted out so i can take it out and run a full tank of gas out in it.

Will also be a photo opportunity i have been waiting for.

RIBS
 

Butch Cassidy

Active Member
ok i will because it seems very peculiar that one min it runs like a scalded dog and then it dies like the cord has been cut and it does not want to start again.

i will check the grounds at least the ones that i can find,, are there any in particular that i need to look for and check ?

I ohm ed out the old ignition coil and it seemed fine so the coil was not the issue.

I also tested the spark plug leads with multimeter and was moving them and tugging on them with no open circuit detected so there OK.

Will go threw the bike and check all grounds really well...

the bike is getting fuel cause i took off the cover and it sprays fuel into the engine no problems ,,, when that bike gets spark it starts instantly. and that is not happening. i will check it thoroughly tomorrow thanks Butch
Always begin at the battery: always, and not just the connections .... but for battery 'movement' while riding... or a power wire rubbed through the casting and shorting out; the ignition housing being loose or having a lose connection; voltage regulator connections; but I still would put my money on the battery connections and somewhere there is short.
Question: does it always happen when the bike gets to a certain temp...? and if at the temp will not restart..?
 

Ribs

Live Free & Ride Hard
when temp is involved, check the cam/crank sensor.
Yeah good idea ,, does the sensor produce its own AC power two wire or does it use 12V power three wire from the bike? i plan on checking it once i find it, haven't looked for it yet but that will be one of the things that im going to check out tonight.

Ill be back in couple hours with hopefully some news. going to take the advice you all have given me and see what i can find.

Spent all day in the freezing cold working on my Dump trucks,,, I'm chilled to the bone but am anxious to resolve this issue.

Catch you all later.
Ribs
 

FrankBDPS

Well-Known Member
If you find a cam sensor let me know where it is. Here is what I think. Pull the fuel hose off of you're carb. Are you getting good gas flow? Look in you're left tank. Look at the the opening to the pet cock clear of debris? Check the screen in you're pet cock. I think you are running out of gas. By the way there is no cam sensor on a 107. They were used on the 117. Good luck and don't give up on it. You will be very happy when you get it fixed and show some Harley's what a real bike runs like.
 

Ribs

Live Free & Ride Hard
Alright I'll check that.
I'm still concerned why I was not getting spark. I just got in today spark plug tester so I'm going to have those connected tonight before I do anything else.

Live Free and Ride Hard
 

Mr. Wright

Knows some things
Supporting Member
FYI, when I rewired my bike back years ago, I went back with a single fire ThunderHeart ignition. I got it from ThunderHeart, and the coil fit under my cover just fine, and I haven't had any problems with it.
 

Th3InfamousI

Administrator
Staff member
If you find a cam sensor let me know where it is. Here is what I think. Pull the fuel hose off of you're carb. Are you getting good gas flow? Look in you're left tank. Look at the the opening to the pet cock clear of debris? Check the screen in you're pet cock. I think you are running out of gas. By the way there is no cam sensor on a 107. They were used on the 117. Good luck and don't give up on it. You will be very happy when you get it fixed and show some Harley's what a real bike runs like.
Frank you got it backwards. Cam Sensor on the 107 and Crank Sensor on the 117.

Cam Sensor is in the Nose Cone. If it's stock it would lead to a Thubderheart module unless someone replaced with a crane which has cam sensor and module all in one unit in the nose cone.

Not trying to confuse everyone just making sure we are on the same page.

Stock one is this one on the 107
Look at this on eBay http://www.ebay.com/itm/302251796922

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FrankBDPS

Well-Known Member
You're right Eric and I stand corrected. I just did not want him to waste his time looking for something that wasn't there. Mine has been updated with the Crane ignition. Thanks Eric.
 

Th3InfamousI

Administrator
Staff member
You're right Eric and I stand corrected. I just did not want him to waste his time looking for something that wasn't there. Mine has been updated with the Crane ignition. Thanks Eric.
He very well could have the same upgrade it is pretty common.

Hopefully he just pops off his nose cone and takes a pic for us! Haha

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Ribs

Live Free & Ride Hard
Update I checked for spark with the testers and I have spark.

When I started on the fuel the crossover fuel line from tank to tank the line seems to be calappsed.
I've drained the tank now to check for debris or blockage in the pet cock.
Also going to drain the carby and check for more debris.



Live Free and Ride Hard
 
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