I'm in the process of trying to get a winter project bike up and running. Its a 1995 XJ600 Seca II with 20K kms on it. Its a Canadian version that has not been been running for at least 8 years.
I have done the following work to it so far:
1) checked valve clearance, intakes were in spec, 2 exhaust needed shim change to get into spec
2) fully disassembled the carbs, ultrasonic cleaned all parts and reassembled
3) new 12v battery
4) rebuilt the fuel pump (vacuum style)
5) new fuel filter
6) descale/remove rust from the gas tank with acid, not using the gas tank at this time, gas is being fed to the fuel pump with an overhead bag and hose, both vacuum lines are plugged properly
7) engine oil and oil filter change, previous oil actually looked new
The issue I have is that I can not get the engine to run on its own or even rev with a twist of the throttle.
I can get some of the cylinders to ignite only with the choke on and with some spray of starter fluid. The engine would run for a few seconds at idle with choke on but then cuts out. I could get the engine to run for closer to a minute at first but I think this changed due to some bad gas. Since then I have drained all 4 float bowls several times flushing with a feed of fresh gasoline.
While trying to get the engine to run, I had noticed that the #2 exhaust pipe never heated up (always cold to touch), so I swapped the coils to see if another cylinder would not heat up but this change resulted in only #4 cylinder actually getting hot, 1,2 & 3 were cold.
I put the coils back to their original setup and now #3 cylinder will not heat up, only 1, 2 & 4 does.
I did check the ohm measurements of both coils and the primary and secondary windings are within spec, 2.9 ohms for prim, and ~11k ohms for sec side with the end caps removed. There are no visible cracking to the coil housings or leads, and I cleaned all surface rust to ensure a good ground.
I did a test to see what coil leads were functioning by pulling one plug lead off the spark plug at a time and connecting a spare grounded plug (gapped to 0.030"). I couldn't see any spark at first while doing this in daylight so I tried again at night in my garage with lights out and did find all four leads do spark but only a light small arc can be seen (same for all 4), not a strong blue arc I was looking for.
I'm incline to replace the coils to see if this is my problem but need some advice on what I should be getting.
The Yamaha parts page does show the two coils due having different part #'s as do my coils on my XJ600, one is 4BR-00-447 and the other is .....448. Do I need to look for 2 different coils or can I buy two identical coils? Pretty sure there is no difference between the two.
I was going to get a pair of coils off of Amazon for $40 but the seller says they are only good for XJ600's up to 1991, is there a difference with a 1991 and a 1995 set of coils? I think there was a change in TDI to CDI sometime in the 80's but that shouldn't affect the coils.
Anyway, any input someone has regarding more info on the XJ600 coils, if I'm going in the right direction or if you think I should look at something else before replacing the coils, would be much appreciated.
