[Rob52]

All of the sudden yesterday my old sled strted a high idle and kill switch would not stall it nor ignition switch would stop it......only after I choked it did it stall.....I let it cool down and it started up, ran fine until it got heated up again then it did the same thing????
Any ideas where to look first?
Thanks

 

[skidoo33]

i would start by checking the throttle cable is releasing all the way, and if is, then check the carb boot's for crack's, and check the crank seal's for leak's if it's sucking air in could cause high idle.

 

[Rob52]

96 Formula SL

Cable is free and carb-boots are in exceptional shape, it seemed like an electrical issue as idle stuck high and the ignition nor kill switches would kill the motor, just flooding it out stalled it!
I ran it while the idle was high and it still accelerated and backed down to that high idle, but nothing would stop the motor except full choke?? By then the engine was pretty damn hot and I had to shut it down somehow....
I guess what I don't understand is why switch and kills were rendered useless?

 

[skidoo33]

I would pull the plugs and check th electrode if it is grey or white it's an air leak. to check while running spray starting fluid around both crank seal's, the head, and base of the cyclinder if the idle rev's higher it's sucking air. I would also double check the carb's that the slider, and needle is not stuck or out of place, i already had a needle come up to high and stick wide open. just a thought. It does not really sound like an electrical issue.

 

[Dbl R]

check for broke or unhooked wire in the kill circuit

 

[Rob52]

96 Formula SL

OK I'll check those thing out!
When it cooled down and I restarted, everthing functioned properly....ignition switch and kill switch, but after high idle kicked in nothing operated!!
Thanks for all the help and input! I will look at it closer in the AM and let you know what I find!!

 

[smallengineguy]

You may have a wire problem, or the stator may be going on it.

 

[Rob52]

96 Formula SL

I talked to another guy who thought this! Sounds to me like it is "dieseling" . Pre ignition getting the head
temperatures up high enough that it is firing the fuel all by itself and not
needing spark to combust .....

But what would cause this? Kind of explains the electrical issue or non reponse to kill or ignition!! Kind of explains what the sucking air would do and heating the motor way up with high idle being air cooled??

Am I to assume right or am I looking down the wrong avenue?

 

[musicfreako]

Exactly ^^^

 

[Rob52]

:thumbsup:Awesome I'll start digging into it tomorrow and see what I can find, want to pull it into a warm garage!!
Thanks for all the help guys!
Greatly appreciated!!
I'll let you know what I find!!

 

[Rob52]

How about a simple v-belt for the cooling fan? Opened up the plastic over the head and was looking around and saw that little belt laying in there not looking right......I would say that might heat things up?? DAAAA!!!!
Hope it could only be this simple!
Thanks for all the help, If it decides too be more I'll follow up a post!
Great Help Guys

 

[Rob52]

Pulled it apart replaced the v-belt for the fan and it is operating fine but it is still running idle up and causing the "dieseling" isssue! I will start looking for air leaks now as it seems to be pointing this way now???!!!
What exactly should the idle run at for this machine?

Its running up to about 2800 almost 3000 during itd diesel fits----higher before I changed that fan belt....