Ironhead Problem!!! (cam installation)

runamuk · #1 14th May 2012

Just changed over to a Generator from an Alternator conversion on my 1979 Ironhead sporty, but while pulling the cam cover off, I was in a hurry and a couple of cams fell out. The bike got moved around the shop a couple of times over a day or two, which kicked the crank outta the initial spot I had it. I replaced the cams (timed them), finished the gen gear and tried to start it up. It actually started however back fired like a bitch; so I realized it was 180 degrees out. I reinstalled the cams correctly and fired it again; it started however ran a little shitty, i quickly realized that the rear cylinder was not firing. However when you crack the throttle or ride it, it seems to fire the rear cylinder and it has plenty of power. The rear cylinder only seems to miss at idle! Confusing. I swapped both plugs and wires, no change. Put spark tester on rear cylinder; it's sparking at idle, at least on the tester. Pushrods are adjusted correctly too. I didn't change anything else. THe rear cylinder is definitely missing at idle tho, I pulled the plug wire off while at idle; no change in RPM and the exhaust is cold at idle.

ANYONE have any ideas??? I posted this a couple of days ago on another forum and had some replies suggesting that the cams were off so I pulled the cam cover AGAIN, they're timed correctly.

Thanks.

big andy · #2 14th May 2012

Dont take this the wrong way but are you sure you have the cams in the wright way one tooth out will make a huge difference. If you dont have a fsm check in the stickys for a picture of the correct cam timming .

runamuk · #3 14th May 2012

I do have a Factory Service Manual and the cams were timed per the manual, also I did check the stickys section on this site (which was great) and it confirmed that I had them timed correctly too.

Also, if the cams were off; I can't understand why it runs strong under load. I would think that having the cams out of sync would cause a problem at any RPM/Load, etc.

big andy · #4 15th May 2012

What ignition system you using going by what you say the problem is not firing at idle but off idle it runs strong.F you are using points check the gap on both the small and large lobe to bigger difference between them will do what its doing Plus if you are running points removing the cams will sent the timming out of wack . If you are using electronic ignition recheck the timming as it probably will be off . Even if you havent touched the backing plate on the points plate or electronic backing plate the timming must be rechecked .But if its points my guess is the points not right hope this helps All the best andy

runamuk · #5 15th May 2012

Thanks for the help, Andy. I figured it out; when I put the pushrods back in I had the front cams on the heel of the lobes, adjusted them just fine. Then my buddy came by and we started BS'n, and drinking. Basically I lost track of where I was in the process of adj the pushrods. I forgot to move the rear cams to the heels, so I basically had the rear pushrods out of adjustment. Doi! That's why I love ironheads; you can screw em up and they still run. That would of probably destroyed an Evo!

big andy · #6 15th May 2012

Glad you got it runnin good .Now go put some miles on her