No start and no spark

[Donlin]

After adding TC's fuse box my 79 Special it wont start. There were no fuses before. Everything was just wired together with butt connectors. I cut the butt connectors off and attached the wires to the new fuse box. I did this one at a time to not get any of the wires hooked up wrong.

It has no spark now. I'm getting 11.8v at the fuse box with the wires for the ignition. I also get 11.8v at the red/white wire where it splits to the two coils. I'm getting fuel. The plugs are wet. I've pulled a plug and cranked it but no spark. I do get a single spark a few seconds after I stop trying to start it. The battery is new.

I've only had the motorcycle for a couple of weeks and have replaced the fuel lines and removed the octy.

Can y'all guys give me some ideas and things to check.

Thanks in advance

Jay

[TopCatGr58]

Hey there Don,

Okay, verified power to coils and TCI, strong new battery and fuseblock, but no spark during cranking. The most common problem for these machines is the PickUp Coil wires, they crack/break due to constant flexing, and then they can't send the trigger signal to the coils.

You didn't say whether the bike actually ran before replacing the fuseblock, but I'm thinking that it did....so it's a bit rare for both PU coils/wires to completely break at the same time. SO...you've got some troubleshooting to do to rule out the PU coils as well as the TCI, but also the plug coils.

With all of your working on the bike, the emergency tip over switch is a point that can cause loss of spark...just unplugging it provide the bypass.

Check your Cut Off handlebar switch, they also corrode and can caues problems grounding the TCI so it won't work.

Keep at it.
T.C.

[Donlin]

Yes the bike was running before it swapped in the fuse box. But I did pull the plugs to take a look at them prior to trying to start the bike. They were almost black. I was going to swap them out for some new ones but it appears that 2 of the plugs have some type of adapter around the threads. Looks as it the heads have been tapped for a larger thread for some reason. Not sure what size it is or even where to get something like this so I just reinstalled them.

Just for grins this morning I went to try and start it. It ran for about 3 seconds then died. I tried starting it again and nothing. I cranked it for 3 or 4 seconds and as soon as I stopped it back fired out the exhaust.

Guess ill start checking all those things you suggested TC.

Jay

[Donlin]

Got it running. Its something in the handle bar cut off switch. I started taking it off to take a look at it and one of the screws started stripping out so I stopped messing with it. Sprayed some WD40 on the screws to help loosen them up. So i figured I would tap on it with the screw driver. It fired right up after that.

Now I've got to figure out whys its back firing in the exhaust since I've put some sea-foam in the gas.

[TopCatGr58]

Hey Jay,

Okay, sounds like you found where someone had previously stripped/crossthreaded the spark plug threads, and put in a Helicoil repair, but didn't use antiseize on the plugs, so when you removed the plugs, the helicoil came out with them! I'm not very familiar with helicoil installation or use, but I'm sure others will chime in with advice once they see this post/reply!

Black plugs....sounds like too rich, can't recall what or if you've worked on the carbs? But you probably need to go thru them and give them a good cleaning if you haven't. Also, checking on the style of the Pilot Jets....there are versions that come in carb kits that are the wrong style and will cause severe richness! But other things like clogged airfilter, even partially clogged exhaust.

T.C.

[Throop25]

whats a tip over switch? is there one on the 81 special and if so where is it

[Throop25]

Hey Jay,

Okay, sounds like you found where someone had previously stripped/crossthreaded the spark plug threads, and put in a Helicoil repair, but didn't use antiseize on the plugs, so when you removed the plugs, the helicoil came out with them! I'm not very familiar with helicoil installation or use, but I'm sure others will chime in with advice once they see this post/reply!

Black plugs....sounds like too rich, can't recall what or if you've worked on the carbs? But you probably need to go thru them and give them a good cleaning if you haven't. Also, checking on the style of the Pilot Jets....there are versions that come in carb kits that are the wrong style and will cause severe richness! But other things like clogged airfilter, even partially clogged exhaust.

T.C.

is there a tip over switch on an 81 special and if so where is it

[motoman]

is there a tip over switch on an 81 special and if so where is it

Under tank between upper frame rails.

[Throop25]

im a newb, whats that look like, my bike ran fine till i had a leaky petcock, i pulled the tank and now i dont have spark?

[natemoen]

im a newb, whats that look like, my bike ran fine till i had a leaky petcock, i pulled the tank and now i dont have spark?

Directly above the ignition coils there is a fram crossbar. There will be 2 things mounted to that bar. One is the headlight relay and the other is the tipover switch. One is goldish colors and the other is black, don't remember which is which but the tipover switch will have an arrow on it pointing up.

[bikerphil]

The tip over switch has only 2 wires going to it, just unplug it to bypass the switch.