Running on 1 cyl... : V-Twin Forum: Harley Davidson Forums

JoeShovel · 11-17-2008, 11:03 AM

OK, So I think I know what the problem is but need to make sure. It seem as though she is only running on one cyl. When I start raising the rpm's she is very choppy and then at times she seems to run fine. Then she back fires a little bit on and off and then I barely feel any exhaust "push" from that cylinder.

I pulled the plugs and they were pretty black. Could it be the coil? I dont think it is a gas issue. I haven't changed anything at all. I let it sit for 2 weeks but forgot to shut the petcock so could I have flooded it in some way? I dont know. Any help is appreicated.

74" 66 Shovel, S&S super E carb, Malory ign, champion plugs. I dont know what coil it is though.

Thanks,

Scooter · 11-17-2008, 05:13 PM

To test if it's running on one cyl, start it up and pull one plug wire.
If no change, that cyl is not hitting. Plug it back in and pull the other plug wire.
It should die.
Swap where plug wires go into the coil to see if the failing cyl changes.
If not, swap plug wires (if they are long enough) to see if failing cyl changes.
If not, swap plugs.
If still no change, do a compression check to see if valve is hanging.

JoeShovel · 11-18-2008, 04:39 PM

Ok, I will try that and report back. I hope it is just a plug issue or coil issue. Those can be swapped about pretty easily.

strokerjlk · 11-18-2008, 05:38 PM

you list malory ignition so I assume you dont have points in your mag ? It sounds like points..could be weak battery or loose cable them shovels run like sh*t when the battery goes south.Maybe a piece of crap in the jet .could be several things . just giving ya some more ideas.
GOOD LUCK.

head · 11-18-2008, 06:21 PM

my 72 flh-stock 74 ci would do that from time to time. it would foul one of the plugs if it didnt start right away. when it cranked it was on one cylinder. a new plug always fixed it. mostly happened when i hadnt ridden it in a few days. it was all stock except an s&s carb someone had put on it.

head

strokerjlk · 11-18-2008, 07:34 PM

[quote=head;1480371]my 72 flh-stock 74 ci would do that from time to time. it would foul one of the plugs if it didnt start right away. when it cranked it was on one cylinder. a new plug always fixed it. mostly happened when i hadnt ridden it in a few days. it was all stock except an s&s carb someone had put on it.
.
YOU ARE SO RIGHT!! I forgot how mine did the same thing if it took a while to geter going.

JoeShovel · 11-19-2008, 08:52 AM

Quote:

Originally Posted by head

my 72 flh-stock 74 ci would do that from time to time. it would foul one of the plugs if it didnt start right away. when it cranked it was on one cylinder. a new plug always fixed it. mostly happened when i hadnt ridden it in a few days. it was all stock except an s&s carb someone had put on it.

head

I'm hoping that is it. Like I stated I had her sitting for about 2 weeks. I will get new plugs and try it out. I will let you all know.

Thanks for the input guys, very new to the v-twin world!!

newultraclassic · 11-19-2008, 06:05 PM

Quote:

Originally Posted by JoeShovel

I'm hoping that is it. Like I stated I had her sitting for about 2 weeks. I will get new plugs and try it out. I will let you all know.

Thanks for the input guys, very new to the v-twin world!!

If not ignition and plugs or wires, do a compression check. A low cylinder will cause misfire at idle.

MarkCrain · 12-09-2008, 04:49 PM

Start it up and let it run for a minute, feel the cyl, cold one ain't hitting. Change its plug and you should be good to go. If not, CRAP, I was wrong.

claydbal · 12-09-2008, 07:27 PM

shovel valve guides are known for sticking.

JoeShovel · 01-06-2009, 09:07 AM

Well, I finally got around to fixing this (just had not time with work and then holidays) and all it took was some new plugs. I got the new plugs, gapped them properly and now she is running better then before. She is starting right up after just one kick.

Thanks guys!!!

strokerjlk · 01-06-2009, 10:06 AM

Quote:

Originally Posted by JoeShovel

Well, I finally got around to fixing this (just had not time with work and then holidays) and all it took was some new plugs. I got the new plugs, gapped them properly and now she is running better then before. She is starting right up after just one kick.

Thanks guys!!!

really JOE
You are going to have to show the old Girl more attention!! LOL!

JoeShovel · 01-06-2009, 11:30 AM

Quote:

Originally Posted by strokerjlk

really JOE
You are going to have to show the old Girl more attention!! LOL!

I know, I know