The governor is not the problem. it's perfectly adjusted (I tried both ways too, just to make sure I had it in full sweep). The carb is not defective. I put the old carb in and it still surges. It's a V twin....I mentioned this weird condition in the first post: when pulling EITHER of the two coils, the engine smooths out. No surging. It does not matter at all which of the coils I pull, the surging stops. BUT when I have them both connected and both are firing, the surging happens. This should have been my first significant clue when I first began troubleshooting. But, I was not paying attention and I ended up replacing just about everything. (carb, fuel pump, fuel filter, all fuel and vacuum lines, new intake gaskets, new exhaust gaskets...new carb gaskets...new breather hose...new coils, new plugs)...I threw parts at it..and I did so knowing that I could end up not solving the surging problem, but also knowing these are spare parts I can keep for maintenance down the road. I cleaned the tank, new fuel...gapped the valve clearance...cleaned up the flywheel and coil mounts of any rust and debris. I did all the things you possibly could except that one thing I should have done in the very beginning.
then I got serious...I did a compression check and leak down.
both head gaskets were blown...both were leaking compression down into the case. The symptom of one coil pulled and no surge is because the gasket problem was very tiny...just enough to cause problems, but only when BOTH cylinders were firing. When only one was firing, the surging goes away because the head gasket leak is not back pressured by the other cylinder...because there is no combustion happening, so there is no backpressure that creates excessive torque load on the shaft!. But when both are firing, and are in different phase...(one in ignition, one in exhaust for example)...causes enough back pressure in the case from both cylinders happening at different cycles then surging happens. The surging happens because the case pressure accumulates enough blow by pressure from the cylinders directly into the case to cause the engine to "feel" it us under a heavier torque load and the governor responds ...with the up and down surge...blown head gaskets...not much...but enough to cause excessive pressure into the case when both are operating...but not enough to case excessive pressure when only one is firing.
If I had started this troubleshoot with a little more attention to the "weird" symptom, and then done a compression and leak down test, I would have figured this out much faster.
sidenote: I did NOT USE the OEM Kawasaki Head Gaskets for the replacement/repair. For one, finding the IMPROVED two part composite gasket (metal PLUS a fiber insert), was too difficult to try and verify with all the garbage that is sold out there in the ether. Even the official Kawasaki website states two different part numbers, one for the original and one for the superceded "improve" composite gasket. But when I called they said I would receive which ever they had in stockl! WTF! And it was very pricey...no way I am going to pay 30 bucks for a simple stamped aluminum gasket. So, What I ended up doing is buying COPPER GASKETS...and used a copper gasket spray dressing. There is no fiber insert on this gasket but it is exactly the correct thickness dimensionally to the OEM gasket, so there is no problem with "squish". They were cheaper by a mile from the IMPROVED Kawasaki composite two element gaskets...18 bucks a piece. Copper should also provide better heat transfer, so there is another benefit by this upgrade.
this is exactly what I bought. And so far, compression and leak down check after replacement has been terrific. No leaks..and compression is 155 at #1 and 153 at #2. (versus below 60 psi on the old blown gaskets)...no surging. Problem solved. It has small leaks in both head gaskets!
as far as why the head gasket failed, both at the same time, is probably due bad metal gasket design PLUS a time or two when my cousin decided it was a good idea to spray down the engine when it was hot.
case closed. head gaskets.
lesson: when dealing with engine performance...do a compression and leak down check. Can save alot of time chasing gremlins
