HELP!!!, runnin out of options

[kurtj]

I have a 1980 GS750ET, 12,000 miles and in nice shape. I have had running issues with the engine quitting just above idle and losing power off the high end. Found original coils on 2nd side at 26 and 27 ohms with cracked wires. Replaced with new dynatek 3 ohm coils, 7 mm wires and new plugs. Engine idles great, doesn't quit. Still losing power at high speed, like it's bleeding off power. Pulled new plugs, dry, black and sooted up from maybe a 20 mile ride. The engine smells of raw fuel when started.I tested the s generator and found it measured 326 ohms Good. Battery fully charged. engine generator charges charges at 14.4 volts at 3500 rpm's. Good. No missing or misfiring.when starting or running. The other issue with this bike is that the starter will work great one time and drag the next before start up. I cleaned the communicator nice and shinny and the brushes are within specs. The fuel petcock works properly. I tested it on vacuum and in the prime position. I pulled it ans found the screen clean. I am getting tired of cleaning new plugs. Don't know where else to look other than test the main ground wire from the negative post to frame and engine block. The ground looks clean and solid.

Any suggestions? Here in florida in december, it's prime riding weather and I don't trust my ride past 10 to 15 miles from the house!

[chef1366]

What's the battery read not running?

[jabberjoe87]

did you test the rectifier/regulator? Are you sure its not a fuel problem

[kurtj]

battery is new. Reads 12.6 volts. Not sure if it's a fuel problem. Had the bike for 2 months now. Spent alot of time reading on this website. Don't want to get in to the carbs unless it's a last resort.

[chef1366]

Carbs are a first resort.

12.6 is low. Should be closer to 13.

[kurtj]

I thought the regulator/rectifier was for charging conversion. How would it effect running performance or plug fouling?

[chef1366]

Check the voltage where the hot wires go into the coils with the kill switch on and ignition on. Should be close to the battery voltage.
I unplug the headlight to do this unless you can turn it off.
If it is closer to ten volts do a search for coil mod.

[jabberjoe87]

my bud had a yamaha r5, one of them two stroke buggers, he had a charging problem/running problem. It would idle and rev, but had no power. Other than this, for the 750 we are talking about it could be a fuel problem

[kurtj]

Thanks, I'll give the the coil voltage test a check.

[BassCliff]

Greetings and Salutations!

Hi Mr. kurtj,

Please click here for your mega-welcome, chock full of suggestions and links to vendors and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Thanks for joining us.

Clean carbs, new intake boots and O-rings will go a long way towards solving a myriad of headaches. How about float height? In unusual cases, I've heard that if your cam timing is off by a tooth it can cause loss at the top end. Keep us informed.


Thank you for your indulgence,

BassCliff

[bikerfox]

i miss the old mega welcome where new people got that giant post sorry ill be on my way :P

[kurtj]

Thanks BassCliff, glad to be a part of this group! You guys are great!!!!

[jwhelan65]

Kinda obvious but sometimes over looked, make sure all your connections are tight. My 1100 was acting similar.. my connection at the regulator was wiggle loose..

[Nessism]

Sounds like either a carb issue or the ignitor. Doing the carbs is first priority since even if that's not the problem, the o-rings are sure to be hard and brittle anyway so it won't be a waste of time to refresh them.

[49er]

Are you running an airbox or pods?

If it's badly sooting up new plugs, that raw fuel smell could be caused through incorrect float heights, incorrect needle clip position and/or too big a main jet. Does the exhaust show black smoke when you blip the throttle?

As Nessism said, looks more like a carb isssue, than electrical!