Jump to content
IGNORED

Cylinder not firing


Recommended Posts

I finally finished with replacing the handlebars an cleaning up the wiring inside the fairing from all the electrical mods I've done. Changed the oil in the engine and the final drive. Decided to pour in a can of SeaFoam while I was at it. Started the bike to pump some oil into the filter before checking the final oil level. I let it run a bit to warm up good. It suddenly starting running rough and had a little exhaust popping. First exhaust popping I've heard since plugging the AIS a year and a half ago. When I tried to roll on the throttle real quick, it tried to stall. Then I remembered I had siphoned out most of the gas before I pulled the tank. It was probably running on mostly SeaFoam. I added the 4 gallons I had pulled from the tank back in and run it awhile. No change. Still rough with a little popping.

 

I pulled out the Carbtune. They were off, but not real bad. I synced them and things did smooth out and the popping stopped. I could roll on the throttle without it trying to stall. Sound seemed different and the idle was lower than it was, but she was smooth running. Finished up a few things and went for a ride. Power seemed less than I remembered. I had to add more RPM to find a sweet spot. I seemed to be using more throttle. I was doing 80 and decided to see what she would do... made it to 100, but it was a slow to get there. Put about 50 miles on the bike and pulled into a convenience store. Decided I better buy some lottery tickets... might need them to fix this! When I got off the bike, I felt the cylinders. Both front were hot. Both rear were warm with the right rear being the warmest and the left rear just barely warm. Decided to buy 2 lottery tickets.

 

Rode to work today (35 miles one way). Had to fill up before I got there. 22.75 mpg. Now a lot of that was wasted transferring fuel, idling and hitting the throttle hard a number of times, but that can't account for all of it.

 

When I got home this evening, I pulled the left rear plug wire from the running engine... no affect. Pulled the right rear and the engine ran rough. On the left side, I noticed when I put the plug wire back on, the engine RPM would come up a little for a second or less then fall back off. Did it every time. It was like a little fuel made it into the cylinder while the wire was off and burned it quickly when the wire was put back on. I didn't have my tools out or have an easy way to check for spark on that wire, but from the reaction of the engine when I put it back on the plug, I would say it is firing.

 

I pulled the air box that goes on top of the left side carbs while I was working on the bike. I'll check that to make sure I got it seated back in place and all the hoses replaced like they should be. I'll also make sure I am getting a spark on the left rear. Where do I go from there? I don't know much about carbs, but I guess I can learn with some help. Be this weekend before I can do much, though.

 

What really amazed me was that this bike would push my 375+ pounds up to 100 mph on three cylinders and run smoothly while doing it!

Link to comment
Share on other sites

first thing first..put in a new plug!!! I've had this happen before and it was just the plug. Also drain the offending carb bowl. One of my cylinders went dead and after I drained the bowl it worked perfectly. I didn't see anything come out that wasn't supposed to be there but, evidently there was. I'd try to catch all the gas that you drain out and take a look at it. I didn't and probably missed what was in there. In doing this you will remove any water or particles that might inhibit gas from getting to the cylinder. Good luck.

Link to comment
Share on other sites

  • 3 weeks later...

I finally had time to work on the bike today. When I put the bike on the lift last week, the exhaust pipe off #1 was cold. I pulled the seat and tank and looked around for any obvious loose wires or hoses but didn't see anything.

 

I hooked up an auxiliary full tank and fired her up to check for fire on the cylinder. Looked good and engine sounded better. Burned my finger when I checked to see if the exhaust pipe on #1 was hot. I hadn't done anything to it yet! I was getting a fair amount of oil smoke out the left pipe. 7k since the last plugs... seat and tank were off... I had some new ones. All 4 plugs were blacker than the last time I changed them and #1 was the worst by far.

 

After the new plugs were in, I noticed the smoking had cleared up. Engine idled a little rougher but accelerated smoother. Synced the carbs and that got better. Put everything back together and went for a quick 25 mile ride. She felt much better for the first mile then started bucking on acceleration. Did that 2 or 3 times and then started running rough without throttle. After slapping my head and turning the petcock from off to run, she smoothed out and ran great!

 

Will see how the commute goes this week, but maybe I can make Houston on the 19th!

Link to comment
Share on other sites

I have found over the last couple of years. working

on the bike and Idling them for a time.. will foul a

plug or two.. same thing has happened to me

a few times. I have a whole drawer full of plugs

that are not that old.. as soon as I change them out the bike

runs fine. I did however go to a # 7 this year. these carbs

run REAL RICH! (specially at idle)

(at least this is what happens to me

better now since I have re-set all the floats)

Jeff

 

Note: Mine Fouls where always on #1 or #3 the rear cylinders.

Link to comment
Share on other sites

i see that you "ain't riding a brand new bike", so i guess i can safely assume, Doug, that your lottery tickets were DUDS!

lol

missed seeing you yesterday in refugio.

guess i'll look at you in houston!

just jt

 

Can't afford lottery tickets! Well, can't afford very many.

 

Wish I could have made it to Refugio, but I had to work on the bike. If I don't shake out any more problems, I intend to make it to Houston... at least for the Eat and Meet part. Some PGR folks in Houston I haven't seen in a long time that I'm going to try and meet up with while I'm there.

 

Hope to see you Saturday!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...