Only one cylinder runs

[acb2]

Hi, yesterday I tried to run my bike (XLH 1981) and I needed the car battery to start it.
But the problem was that only the rear cilinder runs, but the front one didn´t.
I hadn´t got the tools there, so I still haven´t check if it´s an electric (plugs, wires..) or a mecanic (valves, pushrod...) problem.
anyone with a similar problem? What do you think I need to check first?
Thanks. Acb2

[hintocycle]

Mine tends to do the same when its cold, but if I start it and dont let it warm up all the way and goose it a little it will foul a plug every time. Check your plugs then wires and you will probably be fine with one or the other. Also check where the plug wire goes into the coil mine broke in there and the wire boot help it inplace without me knowing until I tried to put the plug wire back on and the wire fell out of the coil. It sounds like a dead plug though. Have fun. Start on the easy stuff. cheers

[CourtHouseCustom]

I take it what you mean by "only the rear cilinder runs" is that the rear if firing and the front is moving fine just not firing. If this is the case, I would check the electrical end of it first. Start at the plugs and work your way to the plug wires, coil, wiring to breaker and ignition, then the ignition/points. Somewhere within all of those items, you should find your problem. Hope that helps.

D.J.

[CosmoTG]

Start with the easiest first. Plugs. It could be anything of course but swapping plugs and wires is a simple task...Cos

[OutlawTexan67]

I would check if it is even firing first on the front cyl first,if it is firing then more than likely you are in for a top end rebuild.

[garbiker]

OK do this pull the plug will let the spark jump under the boot to the plug. let it run and it will clear up I have let mine run for a few miles this way and saves pulling plug as will clean up a wet or oil plug from sitting if it ran good when you parked it then as you ride push the boot back down good luck a old trick I have used for years

[acb2]

Thanks everybody, I´ll check first the electrics posibilities.
Thanks again.

[linex82]

Originally Posted by CosmoTG

Start with the easiest first. Plugs. It could be anything of course but swapping plugs and wires is a simple task...Cos

I'd swap just the plugs first - one thing at a time. This happened to me, and the front one was bad. I ended up just replacing them both, because the bike was new to me at the time. I tried to pull the plug and see if it was jumping - and shocked the bejezus out of myself. (and laughed about it, of course)

[garbiker]

well no need to try and tell you guys any thing. 50 years ex on harleys?? IT will work. From a old harley mechanic. gar

[Shadowdog500]

Originally Posted by garbiker

OK do this pull the plug will let the spark jump under the boot to the plug. let it run and it will clear up I have let mine run for a few miles this way and saves pulling plug as will clean up a wet or oil plug from sitting if it ran good when you parked it then as you ride push the boot back down good luck a old trick I have used for years

I will give this a try if i ever get this problem. I assume this clears out oil or water from within the boot?

Thanks,

Chris