650gl won't start

[Anonymous]

I just changed the head gaskets on my bike. Put everything back together fine. But now the engine won't fire. It is like the engine kill switch is constantly on off (even when on). I checked connections to the switch everything is ok.
Could this be a gas problem with the carbs that I had to take out and put back in.
I also replaced the gasket on the stator cover and noticed electrical tape around the wires from the stator where they go into the starter housing if I pulled the wires loose somehow would it cause this problem.

I am very puzzled as to what is going on any help would be great. Thanks.

[Anonymous]

You're not giving us enough information.

In order to fire, an engine needs the following:

FUEL mixed with air in the proper ratio, which is sucked into the engine and placed under COMPRESSION and then, undergoes IGNITION at the proper TIME.

If all 4 of those factors are met correctly, it is almost certain the engine will run.

Start with Compression, then check your Timing and Ignition and last but not least, make sure you are getting enough fuel.

[Dark Jedi]

Open the airbox and spray in a shot of starter fluid while cranking the bike. (A bungee holding the clutch for you makes this WAY easier..)

If it tries to fire, you have a fuel/air problem. If you get nothing, I'd suspect spark or timing.

Pull the plugs after cranking. Are they wet?

Take that pulled plug, re-attatch it to the plug wire and sit the electrode on the engine casing. Crank it and watch for a nice fat blue spark in the gap.

A weak, yellow spark will not do the job, check your connection to the coils and your gap.

Get a compression tester, and check the cylindars. maybe the new gasket was too thick. i've seen this before, and compression was WAY down. look for >120psi in each cylindar.
Also, do a wet and dry leakdown test, and see how well it holds compression.

[lhanscom]

Check for spark, if I were to guess, I'd say you might have disconnected the positive wire to the coils. It would be easy to do.

[Anonymous]

There is compression, but I do need to get a gauge to see if it is correct. The timing I set according to the manual and rechecked it so that should be fine. I will try everything suggested.
Thanks for the help.

[Anonymous]

Also, do a wet and dry leakdown test, and see how well it holds compression.

Don't know how to do this.

[Anonymous]

O.K. so I checked the spark on all the plugs and every one is very weak. Just a faint yellow spark. Since the bike started well before I worked on it. I don't believe that the coils are the problem I checked all the connections.

Would you say that the timing is the culprit.
If so what is the best way to set it. I have a Clymer manual that has instructions, I think maybe I am confused about the TDC mark.

[Dark Jedi]

Well, first check all the connections to and from the points/ignition module.
82 650GL? That would be ignition module. Make sure the connections are all clean and firmly seated. Those barrel and spade connectors are easy to work with, but they corrode way too easy.

I bet you have a loose or dirty connection in there somewhere.

And FYI:

Dry leakdown test: Compress the cylindar with a compression gage in it. see how long it takes to bleed down from your compression pressure. (My bike was 124 across the board.) It should take a bit to go down. if it just swings back to zero fairly quick, you have a leak somewhere.

Wet: Do the same, but put about a teaspoon of oil in the cylindar before starting. if it leaks down a lot slower, you have ring problems. If no difference, you have valve problems. Do a wet test if a problem is found on a dry test.