Need Help Craftsman yd4000 Runs too fast after normal start and run for a few mins.

[ToolmanTony]

I need to find why my tractor 2008 yt4000 Craftsman is gaining very strong power after using it for a few mins on normal setting. as if it had a turbo charger on it.
I am not able to reduce throttle speed back to a low idle it remains high.
Any thoughts, very weird , it runs great but sounds as if the engine is about to self destruct.

 

[StarTech]

Without the engine model number I suspect you v-twin OHV Briggs with govern idle setup or at Searspartdirect pulls up a Briggs 44 series engine used on one version of the YT4000. These must tuned using a tach and the service manual at hand. When adjustments are not correct the engine will try to run at full throttle and you can't get it to idle back down.

 

[ToolmanTony]

Without the engine model number I suspect you v-twin OHV Briggs with govern idle setup or at Searspartdirect pulls up a Briggs 44 series engine used on one version of the YT4000. These must tuned using a tach and the service manual at hand. When adjustments are not correct the engine will try to run at full throttle and you can't get it to idle back down.

Yes sorry the model is 4456 77 1188 B1
I have worked on engines all my 63 yrs and never saw one do this.
Is it something I can do with tech and dwell meter ( that is a old tool ) LOL

 

[ToolmanTony]

Yes sorry the model is 4456 77 1188 B1
I have worked on engines all my 63 yrs and never saw one do this.
Is it something I can do with tech and dwell meter ( that is a old tool ) LOL

OK as far as adjustments I have never touched anything other them basic tune ups over the yrs. It is a hard start and choke does work properly, I am going to adjust the valves tomorrow >.04-.06 . Thank You

 

[ToolmanTony]

Without the engine model number I suspect you v-twin OHV Briggs with govern idle setup or at Searspartdirect pulls up a Briggs 44 series engine used on one version of the YT4000. These must tuned using a tach and the service manual at hand. When adjustments are not correct the engine will try to run at full throttle and you can't get it to idle back down.

Im sorry folks
The model is 4456771188B1 / 445677 it is twin cylinder ohv. 2009/march
When it starts up throttle works fine low to high speed. When warmed up after cutting 15 mins the engine revs like it is on nitro, that is when I pull throttle to slow position and it hardly drops RPMs or powr.
I did remove carb last year but it was fine after install, The problem was from the end of seaqson last yr .
I wonder if I bent the linkage? But if I did would it not be high speed all the time?

 

[ToolmanTony]

Without the engine model number I suspect you v-twin OHV Briggs with govern idle setup or at Searspartdirect pulls up a Briggs 44 series engine used on one version of the YT4000. These must tuned using a tach and the service manual at hand. When adjustments are not correct the engine will try to run at full throttle and you can't get it to idle back down.

I found this video What do you think?

 

[ToolmanTony]

Follow up
All fixed , runs great now
Needed the idle spring adjusted, the tang needed to be bent up a bit. Boom like a new machine again
Thks All
Tony