No spark to 1 & 2 cylinders

[Stralya]

Hi once again.

I've been searching the forum for an answer to this problem of mine and had no luck so here goes.

I recently installed a set of Goldwing handlebars to my '78 XS11E. In the process I had to install a longer clutch cable so instead of removing the tank and seat , I taped the end of the longer clutch cable to the end of the existing cable and pulled it through. Seemed like a good idea at the time.

Anyhoo, as soon as everything was done, I started the bike and off I went, sadly however, I found I was struggling getting over the speed bump in my driveway.

I checked the exhaust manifold and found that pipes 3 and 4 were hot and one and two were cold.

Given that coil one supplies juice to cylinders one and three and coil two serves two and four, I figured both coils were OK.

I noticed that one of the kill switch wires had come loose so I re attached it. Other than that there is no obvious problem.

I changed the ignition unit to no avail, checked the pick up coil wires and they seem to be fine.

I just don't understand how cylinders one and two are not firing and three and four are. It would be easy if one and three or two and four were not firing but one and two?

Over to you guys.

Dan.

[Ken Talbot]

One and two will be deaqd if they're not getting any fuel. Check to see that you didn't pinch a fuel hose somewhere along the way, or inadvertently disconnect the vacuum hose that operates the left side petcock.

[Stralya]

Thanks Ken, I'll check that.

Dan.

[John]

The #1 & 4 cylinders are on the same coil, and #2 & 3 are on the other, You must have done something to the fuel supply to #1 & 2 carbs, they share a common fuel supply.

[Stralya]

Thanks John, I haven't checked yet because I'm still at work, but I will, I'm sure it's something to to with fuel, I'll let you know what I find

[Stralya]

Thanks fellas

Yep, sure enough, I'd knocked one of the vacuum pipes off that wasn't readily visible. I hooked it back up and now it's perfect again, in fact, all the checking and stuff I did have improved the performance, it fair dinkum screams now, arm wrenching power like I've never experienced!

Thanks to you both.

Dan Tyson.

[John]

Hang on tightly, mate!