Any fixits for my barely running 99 750C?

[The Tone]

Several months ago I cranked up my bike and was pulling out and it killed. I cranked it over and over and it wouln't even cough. It had been running fine,  so I figured it was electrical to just have died like that. I still had spark at my NGK plugs, but it seemed a little weak (sparking to the side, not the tip). Did all theignition tests in my manual and everything checked out which meant if it was ignition related, it was a faulty ignition control module. I let it sit for a few more months(didn't drain the carbs) and started tinkering with it again. I was finally able to get it to start and run with ether continuously sprayed into the carbs. Figured it may be fuel related so I bypassed the vac. fuel valve with clean fuel from a rigged up tank. No dice. Finally before throwing in the towel I got new Champion plugs. I never replaced the plugs before, cuz the bike had started right up before, which implied the plugs were ok. Anyway, I am now able to start and run it with the choke out, but it has no power and dies when I start to push the choke. I still feel it is an  ICM issue. Any suggestions? Thanks

[Gloveberg]

I will not claim to be a mechanic but I still think you have a fuel delivery problem.  The fact that is runs with the choke out and/or with spraying ether in the carbs seems to say the ignition is doing it's job, it's just not getting fuel.  Possibly a pinched vacuum line.  Where are you located?

[roboto65]

Well I am going to have to say that the first thing you need to check is the carbs after sitting for a couple months with the bowls full of fuel well that just tells me that those jets are clogged I have the same problem I can almost say for sure thats what it is after sitting plugs just don't go bad fuel on the other hand does and when it evaporates its leaves gum that is bad especially for the idle or slow jet you could try a fresh tank of fuel and some techron or the like.I have heard transmission fluid works have not tryed it yet for I am working off shore right now. When I get home I have to tackle mine but I would most definatly check the carbs it is not electrical almost 99.9 % sure..... Good luck

[Greg Cothern]

Yep your problem it completely the carbs!  You will need to pull them and clean them if you want it to run right.  Sure running cleaner through it may actually get it running enough to ride to which it will get better.  But you are making it very lean which makes it run very hot and that is not good.
Running with the choke all the way out will only succeed in fowling the plugs and making the situation worse!
Where are you located?  I have cleaned quite a few of them to date I am more than willing to help out, let me know.

[The Tone]

Well ya'll, I'm in New Orleans, actually. I found your group and saw ya'll were pretty active, helpfull dudes, so I posted. Thanks for the offers.

I still feel the poor running is due to the problems that initially caused the bike to kill in the first place. I find it weird that replacing the plug got it started and running if it is a fuel issue. Someone recommended Sea Foam for cleaning the carbs, so I'm gonna try that. I've also gotta check the timing to verify the ICM is getting that right and check for some loose vac hoses or something.

[roboto65]

I am now able to start and run it with the choke out, but it has no power and dies when I start to push the choke.


This alone would tell me that the carbs are clogged Had the same exact prob with mine when I got her from her prev owner had to pull the choke and run it that way up and down the street but she still won't idle have to work on that when I get home......

[Gloveberg]

I still feel the poor running is due to the problems that initially caused the bike to kill in the first place. I find it weird that replacing the plug got it started and running if it is a fuel issue.

Here's the thing.  If you had a fuel delivery problem to start with you could have easily fouled the plugs trying to start it.  Then it sat for a while which worsened the plug situation so when you changed them out it cured THAT problem which was probably caused by the initial issue.

If it will run with the choke then you are getting spark.  If it was ignition problems then it should not matter what the choke was doing.

Bottom line is the carbs should probably be pulled and cleaned and vacuum lines checked for holes or kinks as well as fuel lines.

[The Tone]

Well, I'm gonna drown the carbs in Sea Foam cleaner first and the run it with that stuff and see what happens. If that doesn't work, I'll get a little more drastic in my cleaning procedures (using Yamaha carb cleaner and a vacuum). We shall see. Thanks.

[rjb/AKA Bob Barram]

When cleaning the carb be sure to spray plenty of cleaner around the trumpets feed air into the chamber. There are about four brass looking holes around each trumpet and they need to be sprayed as well, hopefully while it is running.
rjb