Green Tractor Talk banner

1 - 8 of 8 Posts

·
Registered
Joined
·
440 Posts
Discussion Starter #1 (Edited)
Three or four weeks ago I posted that I had left my ignition switch in the "on" position on my Z710A. One or two replied that they had done the same. Well!. that is not good, and here's why.

When I found that I had left the key on, I started the engine and "white/Blue" smoke bellowed out the exhaust for a minute or so. Not good. Didn't think too much of the matter at the time. I connected the Battery Tender to the battery and recharged it.
Today, I went out to start the Z710A and "again" white/blue smoke showed it ugly head. So, I checked the oil, and there Gentlemen came the words...."Not Good" as the oil level show about two quarts over-fil on the dipstick. Results....gasoline. And would you like to know where it came from? I get the Z71-A repair manual out and here's what happens when the key it left on the "on/run position" The voltage is sent to the "engine shutoff solenoid " and it opens to allow fuel to the carburetor. And somehow the gasoline gets past the float-bowl and into the engine.

I remembered that I ran the engine about three or four minutes when the fuel in the crankcase. So, I must change the oil and filter, hoping that I didn't damaged the cylinder walls and all the rod bearing, etc.


However, should it come down to replacing the engine. I'll just snap in a new Kohler ECV730 Command Pro EFI 23 HP 747cc at a cost of about $2000.00. EFI that sounds like a Electronic Fuel Injection dude.
 

·
Old Pa-pa
Joined
·
11,844 Posts
Kind of doubt you did any damage with running just 3 or 4 minutes, thinned out oil, but none the less oil.

Not sure the type of engine you have, but would have thought a good needle valve and seat with the float properly set
should have prevented this even with the fuel shutoff valve engaged in the open position.
 

·
Premium Member
Joined
·
5,818 Posts
Kind of doubt you did any damage with running just 3 or 4 minutes, thinned out oil, but none the less oil.

Not sure the type of engine you have, but would have thought a good needle valve and seat with the float properly set
should have prevented this even with the fuel shutoff valve engaged in the open position.
I doubt you caused any issues. I did something similar in my HPX gator a few years ago. No issues.
 

·
Registered
Joined
·
440 Posts
Discussion Starter #5
Thanks to all for your advice and concerns.

I made a trip to the local John Deere dealer today. Talk to some length about what happen to my Z710A with the key left on and the full shut-off solenoid pumped gas into the crankcase. He said., "that rarely happens and if it wasn't ran at full throttle for a length of time, there probably wasn't any damage to the internals parts of the engine." He also said., "some of the Kohler CVS680 V-twins had a model carburetor (and didn't remember the carb number) that had problems with the needle seat bore not true and there allowed gas to flow into the combustion chamber and into the crankcase even after the engine was shut down after use." He said., "if I have white smoke at each start-up...(And I do at times) I have one of those carburetors with the bad needle seat bore." He told me they replaced many of those carburetors under warrenty on the Z710A.

I mentioned to him that I was installing a fuel shut-off valve near the fuel tank and would shut the fuel off and let the engine die from starvastion. sp.
 

·
Premium Member
Joined
·
808 Posts
And....you're going to replace the faulty carb too right?
 
  • Like
Reactions: H-D dealer dude

·
Registered
Joined
·
440 Posts
Discussion Starter #7 (Edited)
And....you're going to replace the faulty carb too right?
I'm going to us the fuel shut-off valve for now to keep the fuel from getting into the crankcase. On this Kohler PS-CV680-3043 engine, it shows they installed four different Nikki carburetor models. It is also very difficult to find the carburetor number without tearing apart the intake assembly. I've also installed a "red indicator light" near the ignition switch to make sure I don't leave the key on again.
There's no problem with the engine performance during mowing... it runs very smooth, so, the float/needle seat doesn't do any damage.

BTW: A new Nikki carburetor is roughly $170.00 to $250.00
 

·
Super Moderator
Joined
·
8,152 Posts
You should be OK. :yahoo:

Plenty of GM automotive engines suffered similar oil dilution when the purge control valves failed. The symptoms were similar. Smoke on start-up, bad gasoline mileage and an odor due to unburned fuel being cooked-off in the catalytic converter.
 
1 - 8 of 8 Posts
Top