KZ750 not running correctly.

Ituen wrote:

...took it to my mechanic. It was the fuel tap. I had it pointed to the "ON" position. He said I should have it pointing at the "PRI" position. Once we did that and I cleared it out, the power is back! I rode it around the block and it runs great. Thanks to everyone for all of your help.

A properly functioning vacuum petcock is supposed to be operated in the ON position until fuel in the tank gets low enough to require the RES position.

PRI allows fuel flow regardless of vacuum, and basically by-passes the ON and RES positions.

When ya run out of gas late at night, alone, on a desolate stretch of road, miles from an open service station, remember to thank the mechanic. :lol:

Good Fortune!

Another problem with keeping it on PRI is that you have the full "head" of your fuel tank pressuring your fuel system when it's off and the only thing keeping your fuel from overflowing your carbs are your float valves.

I'd recommend seeing if you can get a rebuild kit for your petcock, or simply get a manual one. That's what I did on my 400.

I'll order a rebuild kit for the fuel tap. Why was it flooding the carbs and running like it was on two cylinders in the "ON" position?

Ituen wrote:

I'll order a rebuild kit for the fuel tap. Why was it flooding the carbs and running like it was on two cylinders in the "ON" position?

Improperly functioning float valve and/or float.

Good Fortune!

bountyhunter wrote:

Clear fuel line should get tossed. You need real fuel hose. That clear stuff causes no end of problems.

Absolutely. That also goes for the non-see-through urethane out there too.

Patton wrote:

Improperly functioning float valve and/or float.

Good Fortune!

So would rebuilding the fuel tap solve the "ON" Vs. the "PRI" issue or is it still the float in the carbs?

Ituen wrote:

Patton wrote:

Improperly functioning float valve and/or float.

Good Fortune!

So would rebuilding the fuel tap solve the "ON" Vs. the "PRI" issue or is it still the float in the carbs?

Restoring the petcock to proper function won't resolve whatever is allowing excess fuel to get past the float valve.

But when the engine isn't running, a properly functioning petcock in ON or RES position will disallow fuel flow into the carb. Whereas PRI position will allow fuel flow into the carb when the engine isn't running.

In the situation at hand, it would seem that both the petcock and carb (fuel valve and/or float function) need attention.

Ideally, with a correctly functioning carb, the float valve should disallow excess fuel into to the float bowl even when the petcock is in PRI position.

Good Fortune!

So the problem lies within the carbs? I'll have to look into having the carbs checked out again. My petcock repair kit came in, but no instructions. Is this an easy job to do?