Bike ran fairly well then....

So I had the bike out today for a quick scoot. I'm still waiting for some new carbs so I know it's not tuned correctly, but I wanted to try out the new seat on the road.

Anyhow, the bike was hard to start - as usual, but once it got going it revved pretty strong. I went aroudn the block 3 or 4 times and right as I was on my way home, it started losing power. It would idle pretty good, but as soon as I hit the gas it would give me barly any power and almost die. I didn't even know if I would make it home. Managed ot get back to the driveway where I let it run a few minutes on the center stand until finally it ust chugged a little and then dies and now it won't start again.

All the plugs looked like they are pretty carbon fouled, but what i want to know is would they get so bad that it'd just cut out and not even start again, and what else could it possibly be?

Any and all opinions are welcome. And yes there is gas in it.

I'm new to KZ's but have over 15 years automotive/cycle savvy so I'll give ya my 2¢ worth.

As you probably already know, an internal combustion engine needs four basic things to function:
FUEL
FIRE
AIR
COMPRESSION--(Not as vital as the first three, but is a major factor at times)
If you take away/starve the motor of one or more of the first three, it cannot run right, or will not run at all.
You noticed power loss after riding for a few minutes, so first check the simple stuff:
I would check for spark first, you prolly know how to do that, should be a strong blue spark, not a brownish weak one.
Spark? yes?
Ok, is fuel getting from tank to carbs?
Petcocks clog and become useless over time (long storage ect)
Fuel to carbs? yes?
Ok, is fuel getting from carbs to motor?
Clogged carb/s is a common prob.
Oh, and check your airfilter/air box for cleaness and proper airflow.
Was the fuel old? older than six months is stretching it.
Did the bike sit for awhile? if so, its time for a tune-up/full maintinence regimen.

carbon fouled plugs : weak ignition, dirty airfilter, too rich.

Try new plugs.

Finally the harder stuff:
Ignition: contact breaker points in good condition?
Timing correct? (refer to manual, if you don't have one get one as soon as possible!)
Wires shorted/burnt/came loose?
OHM test for coils checks out? (don't need to go to this extreme, if your getting fat blue spark from both coils, your good to go.
Battery in good condition/full charge?
Lastly: do a compression test.
Thats about it, if one or more of the above is not "good to go"
Then your bike won't run
I just got my KZ650 about a month ago, and it was a hard starting, sniveling little bastard, (last guy let it sit in his yard for ten months!)
After my dyna-s upgrade, fresh gas, new plugs, and an oil change she's running almost 100% I'm gonna re-jet 'cus I'm running a tad lean (4-1 header, K&N filter)
Rebuild the carbs, sync 'em, and then its vroom vroom time! (hopefully)

I hope I've helped......good luck!!


Post edited by: fallenknight308, at: 2006/05/01 10:20

Post edited by: fallenknight308, at: 2006/05/01 10:25

Post edited by: fallenknight308, at: 2006/05/01 10:26

Whoops, dang double post :whistle:

Post edited by: fallenknight308, at: 2006/05/01 10:13

I would pop off the cam/valve cover and check the clearances. If the valve clearances are tight they will hold open the valves a bit when it gets hot, and you really lose power. It's most noticeable at idle after running around and getting the motor hot.

Just remembered, make sure your gas tank cap is venting, and double check your carb float levels, using the wet method outlined in your manual.

Post edited by: OKC_Kent, at: 2006/05/01 10:47

I had the same symptoms only after the engine got good and hot.Run engine and get to operating temp.and check your valve clearance.After the engine cooled down did it restart and run as before it died?As said earlier tight valve adjustments will cause this.Check the obvious first fuel delevery,spark and so on.