Hello all, I want to state that this is my first post on this forum, but I have been stalking these boards for the last two years during my FL350 rebuild. And I have to give a big thanks to all of you who have helped my project along, even if you didn't know it! Unfortunately the time has come where reading posts will not solve my problem. I need some help from the big guns. I know that a few of you guys are in Michigan, (I'm in Ann Arbor) perhaps one of you can assist. I'm willing to put the machine on a trailer and drive it as far as I have to, and pay whatever it's worth to solve this issue. I have way too much invested in this machine to quit now.
So here goes, I'll try to keep this concise and get to the root. I had the engine rebuilt completely last summer. Every bearing, every seal, every gasket, and had the cylinder bored for an 80mm piston (it was still on it's original). I put it in the machine, set the idle, heat cycled it, then set out for the maiden voyage. Except that the voyage really didn't happen. Under load the engine bogged to literally 1/100th power. It smoked like a chimney, wouldn't rev over 3-3.5K, and couldn't event make it out of my driveway.
I tried running it without the airbox. Grounded the backup switch to defeat the rev limiter. Replaced the entire power side of the ignition circuit. And still no improvement. So I decided to check the compression, it was only at 90psi. (I had the kids at the local college do the rebuild, and apparently the cylinder head was over-torqued and made the cylinder into a hexagon) which wiped out the rings. I assumed that the super low compression was to blame. The engine didn't even have enough vacuum to pull fuel. So I tore it down again to have the cylinder re-bored. Time marches on.
I finally got the re-re-built engine back in the machine. Fired it up, set the idle, blah blah. Hop in for a spin and.... same exact behavior as before. No power, no revs, tons of smoke. Check compression, 125psi, which seems reasonable considering the rings haven't fully seated yet. Should be enough to make more power than it does anyhow. And even though the compression is a bit low, its within about 5% and should have at least made some improvement over the 90psi that the last one had. But alas it did not.
A few things I noticed this time around: Although it idles it doesn't sound quite right and it's not a smooth idle. I checked the spark and it seems a bit weak and erratic even though it has a new coil. Being a mechanic in the automotive field for more than a few years, I know that it's rare that modern ECU's and control modules fail, but this one isn't modern. And I always like to rule out everything else first. However, at this point all signs point to a bad CDI module. It's about the only thing that has not been replaced.
Ideally I would like to find someone with a running machine that I could swap CDI modules with to see if that is the culprit. Other than that, I'm completely at a loss.
Sorry if the post was long winded. Just want to give y'all the most info I can.
Thanks in advance for any help that you folks can offer!
JV