Saving a '81 KZ750-E

Oh, then no worries - you'll be out for a drive next weekend, eh?

Yeah, next weekend in, like, 2026!
 

I finally got the replacement fuses.  All appears to be fine now.  I got two extra fuses in case the last one went bad due to other reasons than age.  At least that way I should be able to make it home on my own.  I am going for my first mountain ride today up around Lake Tahoe.  I have laid out a loop that's about 50 miles or so.  First time on the twisties! 

Hopefully I will make it home under power instead of a trailer sometime.  It ran great for 30 miles, now it's barely running.  Sounds like fuel starvation.  

 

You're nt having much luck  Hope you find the problem and get a good ride in!

I took off the tank and drained the float bowls.  A normal amount of fuel came out, leading me to believe none of the float needles are stuck closed.  There was a small amount of particles in the fuel filter, but not enough to show serious concern.  When I blew through it, it seemed a bit restrictive, though.  I blew through a new one, then back to the one that was on the bike.  Once the old one was dry, it seemed to have the same restriction as the new one.  When it had some fuel in it, the first blow through seemed more restrictive.  There is no direction of flow anywhere on these filters.  Is this too cheap of a filter?  Is there better ones out there rated for a higher flow?  I chose this type so I could easily see any debris coming from the tank.  The only things left I can think of doing is to drain the tank and pull the Pingel petcock, and pull the carbs and remove the float bowls and inspect the inside of the carbs.  The petcock is flowing full force in both main and reserve positions, so I don't think it's screens are being blocked.  That just leaves the pulling the carbs and float bowls.  Thoughts? 

I may be barking up the wrong tree.  I decided to pull the spark plugs and do a compression test.  I have around 100 miles on this fresh motor, so I thought it would be good to check.  From #1 to #4 the readings are 120, 120, 130, 130.  That doesn't seem abnormal to me for a new motor with so few miles.  I did find, however, that the #2 and #3 spark plugs were fouled.  When the bike started running poorly, I was going down a fairly steep stretch of road and did some decelerating on the motor.  Why would only the #2 and #3 plugs foul? I have brand new Dyna coils (3.0 ohm, green), but both of those cylinders are on the same coil.  Is it possible for a new coil to fail?  Is there a method for testing to see if the coil is still good with a multimeter?

 

Fuel filter don´t like those kind of hose clamps. You will deform the filter connector pipe and restric the fuel flow.
Only use spring circlip clamps or special fuel hose clamps.

 
 
 

Cyl. 2 and 3 running to rich, choke or enricher circuit not fully closed?

So just a coincidence both fouled plugs are on the same coil?  The choke seem to operate smoothly.  Enricher circuit?  As far as I know the choke lever only closes the butterflies.  No other mechanical connection to the choke lever on Keihin CV34's. 

Pulled this from Dyna website to test coils

I went to test the coils, and I found one of the wires broken.  I think I found my smoking gun!