Mantis tiller compression

[tkos115]

I have a mantis tiller that is a bit hard to start and won't run at idle. I usually have to hold it around 1/4 throttle or more. I have put a new plug in as well as a new carb since it sat for several years. After checking compression it's making approximately 70-75psi pulling in over with the throttle held open. I'm assuming that's too low but wanted a second opinion. I haven't looked in the cylinder bore yet.

 

[sgkent]

I would think that psi would work. My mantiss went thru those Zama carbs like a kid eats popcorn at a movie and the carbs only lasted six to eight months if I left ethanol fuel in them. If I drained it and ran it dry I could get 2 years out of one. The diaphragm under the carb that doubles as a fuel pump would warp so that the flap that acts as the pressure valve for the fuel pump portion would not seal and would be the culprit. Those carbs are really inexpensive unless you buy them at full retail. The repair kits for them are only a couple dollars less than a new carb. Literally I could replace one, run the tiller perfectly in March, then go to use it again in October and it ran poorly even with new fuel. Swap the carb to the spare one I kept in 5 minutes, and it would run perfectly until I needed it again the next spring. But drain the fuel and run it dry it would work 2 more seasons. My Toro mower is on the same carb since 2006. My edger carb was just replaced after 25 years. Same for my pressure washer which just got a new carb after 25 years. My Echo leaf blower uses the same carb as the Mantis tiller, and it lasts 3 to 5 years if I drain the fuel each time. If I don't it fails every year. I just started using canned fuel this year cause I am tired of having carbs fail due to swollen rubber and corroded metal parts.