The parking brake switch is broken or you have a short somewhere in the wires coming from it.
My switch broke and I have been looking for a way to bypass it altogether. Both wires need to be connected to start, but they need to be disconnected for the secondary rev limited to be removed.

Anyone know how to bypass it or remove the secondary rev limit?

 

Sounds just like the problem I had. I did just about everything you mentioned as well. Turned out a dead battery was the culprit! Apparently the charging system alone is too weak to operate the engine above a certain rpm since a higher rpm requires more electrical power (it is also possible that a faulty component in the charging system is resulting in low output). Charge/replace the battery, I'll bet that's your problem! Or as a test you can start the engine and then attach a battery charger to the battery and see if the problem goes away.

 

Look, this has to be a common problem with the Suzuki LT-Z50.. I have the same exact problem, every time we take the quad out my daughter might be ok on it for the first few minutes then it starts doing that bog stuff.. Other times we cant get it running right in the beginning and then its just starts running fine a little while later.. The whole experience of owning the bike which fits her size like a glove is draining my patience.. If there was another manufacturer that I trusted (Like yamaha, Kawasaki, Honda) that made the same size tiny 50 with the tiny levers and grips etc, I would sell this one and buy one but the Raptor and KFX etc are just too big and too fast for her right now..
Ive always been partial to Suzuki but this throttle problem is just plain dumb for such a basic little 50cc bike to have constantly..
Ive tried all the stuff mentioned, cleaned spark arrester, had carb apart about 4 times now, new fuel, new battery, etc..
Please somebody with experience with this bike chime in and help us all..
Im a veteran mechanic of 20 years on heavy equipment and this little booger has me stumped..

 

I would also recommend checking the parking brake switch located directly below the lever you press to set the parking brake. This switch started giving me problems as well. I believe this problem is due to poor design which causes the switch to become jammed if a little dirt or debris gets into the hole that the plunger on the switch slides through. The switch cannot be bypassed since it must be closed to start and open to run. I eliminated the problem with the switch by simply replacing it with a toggle switch that I mounted on the gas tank shroud opposite the ignition switch. With this configuration, you turn the toggle switch on in order to start the engine, then turn it back off in order to run once engine has started.

 

Im not understanding how an off/on parking brake switch would make it bog intermittantly?
Did yours do this?
Wouldnt a faulty switch just make it not start?

Ill try anything, season here in AZ is fast aproaching and its time to get this booger ready to ride again but i just dont understand how that switch could cause these symptoms....

The bike literaly dies if you give it too much throttle when its running poor, if I were to leave the p-brake switch on and rev it that wouldnt make it die would it? To me it seems the switch would either work or not work..

Also weird is when it runs fine, it runs great. No hesitation, no dying, no bogging... I just wish it ran fine more than it ran crappy.

 

If the parking brake switch is stuck with the plunger down, then the bike
would still start even without the parking brake lever being pulled. The issue comes when you go to rev the engine, because these bikes have a built-in safety that engages a secondary rev limiter when the parking brake switch is depressed. So if the parking brake switch is stuck at a point where the internal contacts are just barely touching, then that could cause intermittent starting and bogging issues as the switch pulses back and forth between open and closed.

In my situation (once the switch problem was fixed) the engine seemed to hit the rev limiter way too soon and would die back down to just above idle before allowing me to accelerate again. This problem went away when I put in a new fully charged battery. Apparently the electronic rev limiter goes haywire if the battery/charging system isn't providing sufficient power.

Just like all the guys who mentioned cleaning carburetors and replacing spark plugs, I thought the problem sounded like fuel/spark problem. But after fixing the parking switch and replacing the battery, I'm running smooth as ever!

 

Never has this happend. That pain in the butt thing works more consistantly than I would like it to. I know this because I always have to walk to her to restart it after it stalls because my daughter isnt strong enoupgh to set the brake for it to be able to start again.

What you said here makes sense.. But without any symptoms or problems occuring that would ever make me suspect the switch in the first place, I have to just go hacking into into bypassing it just to verify its not the problem.. Kinda sucks but its a place to check i guess..



I put a new interstate battery at the end of last season (not even a year ago), I do throw the battery tender on it to top it off even though I never need to because the bike keeps it charged just fine. So no problems with batteries or anything like that.


Thats me, ive had my carb off like 4 times now bound and determined that the problem is a fuel problem but cant find anything wrong in there..
Online I can find this problem with these ltz50's everywhere, but no definitive answers from anybody experiencing the same exact problems.
When I find the answer, I will surely post it everywhere..

 

here's an "old" 2007 post about the same thing, i think, they talk about changing the cdi to a ltz 90? y'all read it...........

http://forums.atvconnection.com/suzu...o-power-5.html

 

I can tell you one thing it is not and that is the battery. I have been running our LTZ50 without a battery for about 2 years now. Just use the pull start and it runs fine...

WHen it bogs have you tried loosening the gas cap? Maybe the hose is pinched and not letting air into the tank causing a fuel starvation problem.

If you could post a video somewhere showing the problem I think that would help a lot in diagnosing.

 

Yep, while out riding and when it started acting up, I kept removing the fuel cap thinking the same thing...
At home Ive removed and cleaned the fuel petcock when I cleaned the carb as well.