TOPIC:

I've just been reintroduced to the world of streetbiking as of last Saterday when I purchased a 1983 KZ750 LTD for $500. This bike is bone stock including those ape-hanger bars (those really have to go) with the only exception being the travelcade seat cover and some bolt-on highway pegs. It has about 13.5k miles. It started right up when I first came by to check it out and idled well on all 4 cylinders. The chrome and aluminum all looks pretty good with a few minor blemishes, and paint looks good except a few issues on the tank.

When I test rode it, it was only 30 degrees out, so i didn't expect it to run perfect. I did notice it when I gave it more than half throttle it did bog down. I figured for 500 bucks, I'll figure it out.

Yesterday I took it out when the weather warmed to a "Michigan" balmy 50. Unfortunately, same bogging issue. I tried it at different RPM's, same deal either way. When I leave the choke on, it goes to about 1/2 throttle running perfect. As I go from 1/2 to 3/4 throttle, it doesn't pull any harder as it should. The last 1/4 trottle is when it really starts to bogg down.

It's worse with the choke off. It seems like after about 1/4 to 1/3 throttle it's bogging, and nearing full throttle it really boggs down.

The previous owner mentioned the carbs were just synchronized, and didn't notice any issues when riding over summer.

I just purchased a carb rebuild kit from Z1 enterprises, and I figure I should start with rebuilding the carbs.

Am I on the right track? The fact that the issue is consistance regardless of the engine RPM leads me to believe it's a carb issue. Any feedback is appreciated.

Thanks!!!!
John

Nice bike! You will love riding it (especially after you get some better shaped handlebars).

I know that others here will chime in, but let me be the first to tell you that you should not touch the carbs until you have checked everything else. I would run a little fuel system cleaner additive through the gas tank, to help break up any gunk from the bike sitting too long. I would remove the cover plate and the ignition advance unit and make sure it is well lubed and functioning. I would also make sure all of the vacuum hose connections are tight, and that you are not sucking air anywhere other than through the intake filter. Finally, I would make sure that you have a clean fuel filter, a properly operating petcock, and no kinks in the fuel supply lines. Then I would check the valve clearances, and the camchain tensioner adjustment. If that all checks out, I would look on this site for wiredgeorge's advice on carb troubleshooting.

You were gonna do all that stuff anyway, right?
\

Great looking bike - with the exception of the handlebars
Looks like you have the original 4 -> 2 exhaust system

I would do everything apeman said before rebuilding the carbs. Do you have a manual ? you can download one here
www.mbsween.com/kz750l3/index.html
mbsween is a member here

Good luck

Post edited by: JR, at: 2006/12/20 21:23

Just my 2 cents, but sounds like it's starving for fuel. Has it been sitting? I agree with the other guys too, check out everything else first. Let us know how it goes...

Wow!

What great feedback. I'm going to try the fuel filter first (sure does seem like it's starving), and go through the ignition, hoses, valves etc. as you guys suggested. Thanks for the link to the manual!

I have spent more rime riding than tinkering up until now, but it's time I learn (plus the weather sucks in Michigan).

I'll let you know how it goes.....

Thanks again.

If its been sittin for awhile, check your jets. Might be a lil clogged. Not much to breakin em down.