Feul injection?

So, I have a 1979 kz750 twin that had been nothing but problems since I bought it in 2013. I have had it tuned by professionals a couple times and it will run great for a couple weeks after. But then, it starts running crappy again.

My most recent issue is that it idles great, buy cuts out under load. I know this means I'm running lean, but I'm at the point where I'm working on it more than riding it. It's always something.

My question is, would it be worth it, or even possible, to switch the bike over to an injection system. If so, hire would I go about this?

Any help would be great. I really enjoy the bike when it's running, but that's a rarity anymore.

There's a first time for everything. :laugh: Ed

Are you sure your timing advance is working properly?

A weak coil or other ignition problem can cut out under load as well. Idle and run fine until you put a load on them.

Perhaps fuel starvation due to clogged tank venting.
When symptoms appear, test run with the fuel cap ajar (loosened and not fastened down) to assure sufficient venting.

Was an aftermarket in-line fuel filter installed before any gasoline was allowed to enter the freshly cleaned carbs?
If not, it's likely that the carbs were quickly re-contaminated by rust particulate in the incoming gasoline.

Good Fortune!

This statement suggests it's contaminated fuel or a rusty tank w/o fuel filter:

AjKZBobber wrote: So, I have a 1979 kz750 twin ..(snip) it will run great for a couple weeks after. But then, it starts running crappy again. ...

Does it cut out at a certain throttle position OR certain rpm? Is there rust or debris in the gas tank?

Sure fuel injection is possible. Source suitable throttle bodies, injectors, and some way to attach them to the head. Get a fuel pump. Create some sort of crank trigger, maybe off a cam lobe. Perhaps a microsquirt to control it all.

Fixing your carbs will be much less work.

The microsquirt FI system is an amazing system, and while not being as complitcated to install as one might think, still not at all cost effective. Beyond the $300 for the control sytem itself(not including the other sensors and throttle bodies and such u have to get), most end up taking it to have it dyno'd when done. It does allow the user to add a wide band o2 sensor in the exhaust so you can achieve a 'closed loop' system where it reads the exhaust and adjusts itself as needed. Also, a very popular thing to do with it, is get a ford EDIS ignition system and coil from scrapyard(as they are very bullet proof systems) and use a 36-1 tooth trigger wheel, enabling the microsquirt to manage everything.

Do you have any links with info on how to do any of this?

Sure, luckily there's tons of info and articles out there on how to install/convert over to megasquirt or microsquirt. There's also a couple of forums with tons of amazing info(much like like this site ) as well.

Places I have bookmarked are:

www.useasydocs.com/quickstart.htm
www.diyautotune.com/support/tech/install/
www.diyautotune.com/support/tech/
forums.hybridz.org/topic/56329-megasquirt-overview-for-newbies/

www.fintechcommunications.com/funstuff/

www.msefi.com/index.php

From a different medium, I found this book to be incredibly insightful, down from the basics, on up, to much, much more:
www.amazon.com/Performance-Fuel-Injectio...rsion*=1&*entries*=0

Is the intake and exhaust stock? I have an 82 750 twin and it runs great even with uni pods and a partially gutted stock exhaust. As previously mentioned, if it runs ok and then doesn't your carbs are likely getting crap in them.