Strong Smell of Gas and Exhaust

650ed wrote: The KZ650 bikes ran perfectly fine in stock trim (mine still does after owning it for 41 years). Changing a bunch of stuff around rather than identifying and correcting a specific problem will usually will lead to more problems, frustration, and plenty of money spent and is still unlikely to make the bike perform as well as it did in stock trim. My stock KZ650-C1 will still starts very easily and will happily run up to 120 mph without a hiccup. I believe the key is simply to perform normal maintenance as described in the manual. But as TexasKZ stated it is your money, time and motorcycle. Ed

Im not throwing money at it to make the problem go away. I always wanted to upgrade to CR carbs like I did on my CB900f below. It was the best decision I ever made and I am strongly considering them for the KZ650. Sooner or later ALL of my bikes will have them. To me $1000 isnt a lot. My CB900F below had a problem NO ONE could figure out. Bike WOULD NOT go over 100mph. A guy in another forum told me it was probably carb, not spark related and highly recommended the CR carbs. I dropped the total of $1,400 on them and the pods and now the bike hits its top speed of 135-140. Im changing the spark plugs in the KZ650 tomorrow to NGK Iridiums. A friend and I looked at it (the bike) last night and could not find an issue, but one of the spark plugs was black as night - fouled.

TexasKZ wrote: If you wish to spend $1,000 to solve a $50 problem, that is certainly your choice. However, the carbs and the sparkplugs may not be the problem. As Nessism mentioned, adding an additional resistance in the high tension side of the ignition may actually create a new problem or make an existing one worse.
It is generally best to identify the problem before randomly installing new parts that may complicate matters, but it is your money, time amd motorcycle.

All of my research indicates using resistor plugs wont cause an issue. I even called NGK and they had an old timer on staff. He said plenty of ppl iridiums on old Hondas and Kawas and its not a problem. He said Harley bikes with ion sensors would have a problem. Also, he said the Dyna S was good to have on my bike, which I have.

When was the last time the valves were adjusted?
Steve

SWest wrote: When was the last time the valves were adjusted?
Steve

Valves were adjusted 3-4 weeks ago when I had the other issue that was sorted. Carbs were synched, valves were adjusted.

LOL. The NGK guy called me back and said for sure I wont have any issues with a dyna s ignition, but to keep my eyes peeled for any top end shenanigans.

Check your oil level to see if you have got fuel in the sump from a shot petcock, quite a common thing.

I’ll still give you $500 for it.

kevski wrote: Check your oil level to see if you have got fuel in the sump from a shot petcock, quite a common thing.

I know youre trying to be helpful but I have said several times none of the fuel lines or the petcock have leaks and I may have mentioned there is no gas in the oil. .

waktaylor wrote: I’ll still give you $500 for it.

'

Dude. We text all the time. You could have texted me that and last time we texted I told you Im not selling it. Not funny and Id like this post to stay clear of "jokes" and tangents.

I will be POURING money in to this bike to make it more stunning than it is:

CR Special Carbs
New paint job on fender tank and side covers
M Unit
New handlebars
and some expensive shocks I havent decided on yet.

I get a kick out of spending. Its sad but Im thankful I have the $

You have one sooty plug...sounds like fuel is flowing right through the carb and into the combustion chamber. I would check the choke mechanism and the float valve, along with the fuel height.

Oh..and I would check the throttle body action, and the needle jet.

hardrockminer wrote: You have one sooty plug...sounds like fuel is flowing right through the carb and into the combustion chamber. I would check the choke mechanism and the float valve, along with the fuel height.

Oh..and I would check the throttle body action, and the needle jet.

Thanks for this. So can I ask a dumb question?

On my Honda CB500 I had a similar issue as the previous owner used jets that were too big. The bike smelled of gas as well, and kept fouling plugs. The situation was fixed with I had the carbs rejetted.

These carbs are properly jetted and were synched about a month ago. Maybe something got stuck?

Im going to tap the carb as i know sometimes things get stuck.

Would all that fuel going into the combustion chamber taint the oil in a way that could causes hydrolock?

Maybe something got stuck?

Im going to tap the carb as i know sometimes things get stuck.

Would all that fuel going into the combustion chamber taint the oil in a way that could causes hydrolock?

Seriously?

You have repeatedly said there is no possibility that this has happened.

1 as noted you have at least one fouled plug and are now changing them all. Good.. Personally I never use a fouled plug once discovered as they never seem to perform properly after they are fouled. I call it gas soaked , and they never give complete combustion after becoming fouled. My educated guess is at least some or all of the gas smell is raw fuel passing thru the motor and puking out the exhaust pipe.
2 Now this doesnt account for what caused the fouling in the first place . So its time to check all systems . Logic is something that was recently touched is not right.
Carbs is where I would look first as dirt or bad fuel may be at fault. Also checking all tune up items and rebuilt areas ( Did something loosen or get overlooked ? )
3 So now once the plugs are replaced run the bike and see if the problem still occurs , and if so is it from the same cylinder that fouled the 1rst plug ?
A broad statement is to tell you to recheck all adjustment which keep a motor running properly. Compression , timing ,good spark, valves, fuel flow from tank, carbs done right?
If you want the CR carbs , thats fine , but I would still want to get the bike running back to its normal baseline of performance. As otherwise the bike with new carbs may still have the same current problem
Hope this helps
Happy New Years
Dave