Pulling Plug wire

Am I wrong for thinking that if I pull one plug wire off the spark plug while the bike is running it shouldnt die? It shouldnt run great and may miss but not die. Right?

 

You would be right if all 4 are firing properly, where you going with this ?

 

I got this bike for next to nothing and am trying to get it running better. I felt all the exhaust pipes and they all get warm when I start it up. It has a little backfire or pop under acceleration and a few after fires in deceleration. But like I said if I pull any one of the plug wires it sputters and dies. Im going to work on it later today but if I remember right if I pull #1 it immediately dies, no sputter just instantly dies. I have spark on all the 4 cylinders but to me it looks a little weak. I havent done a whole lot to it just changed the oil, cleaned the carbs, put it a new set of plugs and replaced the plug boots. The previous owner had an aftermarket exhaust with out a muffler, so I added a new cone muffler to it as well. This was someone else's "Project" that Im trying to get ready for the summer.

 

Electrical troubleshooting is difficult (but only for me!).
Throwing a dagger in the dark here, if the bike is tuned properly then pulling a plug wire should not stop it, because your bike is stalling it doesn't necessarily mean you have an electrical problem.


Does the bike idle at a proper rpm?
When is the last time the valve clearances were checked?
Carb rebuild (wet set, colortune, synch)?

I thought popping on deceleration is indicative of a lean running condition, no idea what popping on acceleration means.

 

Yes the idle is smooth. Even the start up is easy. I was planning on syncing the carbs and running a compression test today. Your right Ill also check the valve clearance.

 

what bike are you running?
have you changed the spark plugs or still using the ones that came with the bike?

do you have a multi meter?
you need to check out the charging voltage when the bike is started and running.

then you should ohm out the ignition system

 

Not necessaraly electrical. Carbs need attention.
Popping and backfiring = fuel mixture issue.
Starting and idling on all four is pretty easy to get right, and usually someone interested in flipping a bike will only go that far.

Read first, then do. Contact Chacal for parts if you need any.

IN THE CHURCH OF CLEAN

The Information Overload Hour

Oh, and do ALL of the things (at least all of the inspections). You will find that there are more problems than just what is obvious. The years take their toll.

 

Sorry I should have started out by saying the bike is an 81 xj550. I did put in new plugs gapped at .25. I did find that it had 2 exhaust leaks so Im fixing that. Ive been chasing an intermittent short or something in the starter. I think I have it traced to the starter relay or some connection under the seat. If I wiggle the wires it makes a connection. I probably need to clean all of the electrical connections. So far having fun trying to figure it all out. But Im sure frustration will come.

 

As "K-moe" said above, "In the church of clean" and "The information overload hour" is a must read for the XJ's Lots of great information that will answer many of your questions.

 

Ummmm... If the coil is good, and there's mice in the wire.....but there's a crack in the rubber, you might find YOU get a pretty good jolt----

 

Hi all given that these bikes run just two coils and a wasted spark doesn't it need a 'full' connection to spark pairs 1-4, 2-3. Meaning that if you pull one plug lead two cylinders will lose spark which may be enough
to stall the others..? Just thinking..

J

 

A path to ground is a path to ground. There will still be a spark at the connected plug. Running like that for an extended amount of time can damage the coil though.

 

Just an update. Fixed the exhaust leaks. Took all of my electrical connectors apart and cleaned them. Checked the carb sync (it was good). Checked the valve clearances and they were all good. Stared it back up and sounds great. I pulled one plug at a time and it kept running. I have alittle more to clean up with the wiring. And hopfully by next week Ill be working on the forks and front brakes. Ill try and post a picture of my little build.

 

went on my first test ride today. I lost one turn signal lense and on bolt fell out, other than that I was super happy.

 

Nice looking bike!

 

Thanks so much

 

Have to ask, how does that seat feel on your bike? I am doing a scrambler style bike & think that might be the kinda seat I am looking at. Nice lines and great color on your bike.

 

I think it fits ok. The frame has a small "dip" under the seat. I kinda have a little OCD think and thought that it might bother me, but its not too bad

 

speaking of seats... Does anyone have advice on where to purchase a prefab seat? was going to build my own but would rather buy a plug and play at this point