trouts2

   I have a similar problem drive problem with an old Ariens 724.  The factory numbers are rubbed off but 924028’ish. 

I put in a hardware store tensioner spring last year but it fell out on the first storm so no drive.  I have other machines so sidelined it until warm weather.  I forgot how I installed it so back to Abby’s and found the answer. 

  Nice post so I’ll get the spring placed in a few days.  I remember most of the posters so know it’s reliable info.     I learned a ton on Abby’s over the years.  Where is Borat these days?

   No, don't bump the rev's on the HMSK80.  Many two strokes get a boost in hp by a rev bump but that should not be done with your
4 cycle HMSK80.  The rpms on the 80 and 100 are both 3600  and should stay there. 

  At least the way I remember is the block size is different between 80 and 100, bigger piston, beefier crank & etc.  I rebuilt 3 10hps and they were very different than 8hp's
   
   The 100 will get you a slight increase in power.

Toro factory model 51936 string trimmer
Carb: Walboro 3074501
25cc

The carb is about $100 and all that is needed is a diaphragm which is has a leak.
The carb is only sold as an assembly and I can't find a kit for it.  I can't find a number
on the Walboro and googling 3074501 for a kit does not get anything.

If anyone knows how to get a diaphragm for this carb please let me know.  

 

The governor adjust is very likely.   You have not given an overview of how it came to run like this i.e sudden,
over time & etc.  If you have not messed with the governor and it was running fine then you "noticed" this
or it's something that happened on the first use of the season then it could be dirt or a starved situation.
Did you spray all carb holes, spray into removed jet/idle ports, throat holes, emulsion tube, and prod
all those places with a stripped tie wrap wire.  Dip the carb in a tank overnight?

Drive clutch, PTO clutch?  Issue as in not turning? 

Does the tractor drive during the 1.5 hours?  Do the deck blades spin during the 1.5 hours.

How many belts have been gone through?  What condition are they in?  My machine had a frozen
tensioner pulley and the belt heated up to an extreme heat, heating up the transmissin pulley to
such an extent it would blister my fingers.  Even with that heat the belt would cool, work and not
split/seperate layers or break.  The edges of the belt became slick and polished.

The thing to have done was check it out as best you could before getting it to a dealer.  Worse case
remove the deck, check that.  Look at all the pulleys, PTO, guides, break, drive clutch & etc.,
and see what is going on.  Since it's at a dealer you might as well have them give an estimate.